An I/O controller for virtual pinball machines: accelerometer nudge sensing, analog plunger input, button input encoding, LedWiz compatible output controls, and more.

Dependencies:   mbed FastIO FastPWM USBDevice

Fork of Pinscape_Controller by Mike R

/media/uploads/mjr/pinscape_no_background_small_L7Miwr6.jpg

This is Version 2 of the Pinscape Controller, an I/O controller for virtual pinball machines. (You can find the old version 1 software here.) Pinscape is software for the KL25Z that turns the board into a full-featured I/O controller for virtual pinball, with support for accelerometer-based nudging, a real plunger, button inputs, and feedback device control.

In case you haven't heard of the concept before, a "virtual pinball machine" is basically a video pinball simulator that's built into a real pinball machine body. A TV monitor goes in place of the pinball playfield, and a second TV goes in the backbox to serve as the "backglass" display. A third smaller monitor can serve as the "DMD" (the Dot Matrix Display used for scoring on newer machines), or you can even install a real pinball plasma DMD. A computer is hidden inside the cabinet, running pinball emulation software that displays a life-sized playfield on the main TV. The cabinet has all of the usual buttons, too, so it not only looks like the real thing, but plays like it too. That's a picture of my own machine to the right. On the outside, it's built exactly like a real arcade pinball machine, with the same overall dimensions and all of the standard pinball cabinet hardware.

A few small companies build and sell complete, finished virtual pinball machines, but I think it's more fun as a DIY project. If you have some basic wood-working skills and know your way around PCs, you can build one from scratch. The computer part is just an ordinary Windows PC, and all of the pinball emulation can be built out of free, open-source software. In that spirit, the Pinscape Controller is an open-source software/hardware project that offers a no-compromises, all-in-one control center for all of the unique input/output needs of a virtual pinball cabinet. If you've been thinking about building one of these, but you're not sure how to connect a plunger, flipper buttons, lights, nudge sensor, and whatever else you can think of, this project might be just what you're looking for.

You can find much more information about DIY Pin Cab building in general in the Virtual Cabinet Forum on vpforums.org. Also visit my Pinscape Resources page for more about this project and other virtual pinball projects I'm working on.

Downloads

  • Pinscape Release Builds: This page has download links for all of the Pinscape software. To get started, install and run the Pinscape Config Tool on your Windows computer. It will lead you through the steps for installing the Pinscape firmware on the KL25Z.
  • Config Tool Source Code. The complete C# source code for the config tool. You don't need this to run the tool, but it's available if you want to customize anything or see how it works inside.

Documentation

The new Version 2 Build Guide is now complete! This new version aims to be a complete guide to building a virtual pinball machine, including not only the Pinscape elements but all of the basics, from sourcing parts to building all of the hardware.

You can also refer to the original Hardware Build Guide (PDF), but that's out of date now, since it refers to the old version 1 software, which was rather different (especially when it comes to configuration).

System Requirements

The new Config Tool requires a fairly up-to-date Microsoft .NET installation. If you use Windows Update to keep your system current, you should be fine. A modern version of Internet Explorer (IE) is required, even if you don't use it as your main browser, because the Config Tool uses some system components that Microsoft packages into the IE install set. I test with IE11, so that's known to work. IE8 doesn't work. IE9 and 10 are unknown at this point.

The Windows requirements are only for the config tool. The firmware doesn't care about anything on the Windows side, so if you can make do without the config tool, you can use almost any Windows setup.

Main Features

Plunger: The Pinscape Controller started out as a "mechanical plunger" controller: a device for attaching a real pinball plunger to the video game software so that you could launch the ball the natural way. This is still, of course, a central feature of the project. The software supports several types of sensors: a high-resolution optical sensor (which works by essentially taking pictures of the plunger as it moves); a slide potentiometer (which determines the position via the changing electrical resistance in the pot); a quadrature sensor (which counts bars printed on a special guide rail that it moves along); and an IR distance sensor (which determines the position by sending pulses of light at the plunger and measuring the round-trip travel time). The Build Guide explains how to set up each type of sensor.

Nudging: The KL25Z (the little microcontroller that the software runs on) has a built-in accelerometer. The Pinscape software uses it to sense when you nudge the cabinet, and feeds the acceleration data to the pinball software on the PC. This turns physical nudges into virtual English on the ball. The accelerometer is quite sensitive and accurate, so we can measure the difference between little bumps and hard shoves, and everything in between. The result is natural and immersive.

Buttons: You can wire real pinball buttons to the KL25Z, and the software will translate the buttons into PC input. You have the option to map each button to a keyboard key or joystick button. You can wire up your flipper buttons, Magna Save buttons, Start button, coin slots, operator buttons, and whatever else you need.

Feedback devices: You can also attach "feedback devices" to the KL25Z. Feedback devices are things that create tactile, sound, and lighting effects in sync with the game action. The most popular PC pinball emulators know how to address a wide variety of these devices, and know how to match them to on-screen action in each virtual table. You just need an I/O controller that translates commands from the PC into electrical signals that turn the devices on and off. The Pinscape Controller can do that for you.

Expansion Boards

There are two main ways to run the Pinscape Controller: standalone, or using the "expansion boards".

In the basic standalone setup, you just need the KL25Z, plus whatever buttons, sensors, and feedback devices you want to attach to it. This mode lets you take advantage of everything the software can do, but for some features, you'll have to build some ad hoc external circuitry to interface external devices with the KL25Z. The Build Guide has detailed plans for exactly what you need to build.

The other option is the Pinscape Expansion Boards. The expansion boards are a companion project, which is also totally free and open-source, that provides Printed Circuit Board (PCB) layouts that are designed specifically to work with the Pinscape software. The PCB designs are in the widely used EAGLE format, which many PCB manufacturers can turn directly into physical boards for you. The expansion boards organize all of the external connections more neatly than on the standalone KL25Z, and they add all of the interface circuitry needed for all of the advanced software functions. The big thing they bring to the table is lots of high-power outputs. The boards provide a modular system that lets you add boards to add more outputs. If you opt for the basic core setup, you'll have enough outputs for all of the toys in a really well-equipped cabinet. If your ambitions go beyond merely well-equipped and run to the ridiculously extravagant, just add an extra board or two. The modular design also means that you can add to the system over time.

Expansion Board project page

Update notes

If you have a Pinscape V1 setup already installed, you should be able to switch to the new version pretty seamlessly. There are just a couple of things to be aware of.

First, the "configuration" procedure is completely different in the new version. Way better and way easier, but it's not what you're used to from V1. In V1, you had to edit the project source code and compile your own custom version of the program. No more! With V2, you simply install the standard, pre-compiled .bin file, and select options using the Pinscape Config Tool on Windows.

Second, if you're using the TSL1410R optical sensor for your plunger, there's a chance you'll need to boost your light source's brightness a little bit. The "shutter speed" is faster in this version, which means that it doesn't spend as much time collecting light per frame as before. The software actually does "auto exposure" adaptation on every frame, so the increased shutter speed really shouldn't bother it, but it does require a certain minimum level of contrast, which requires a certain minimal level of lighting. Check the plunger viewer in the setup tool if you have any problems; if the image looks totally dark, try increasing the light level to see if that helps.

New Features

V2 has numerous new features. Here are some of the highlights...

Dynamic configuration: as explained above, configuration is now handled through the Config Tool on Windows. It's no longer necessary to edit the source code or compile your own modified binary.

Improved plunger sensing: the software now reads the TSL1410R optical sensor about 15x faster than it did before. This allows reading the sensor at full resolution (400dpi), about 400 times per second. The faster frame rate makes a big difference in how accurately we can read the plunger position during the fast motion of a release, which allows for more precise position sensing and faster response. The differences aren't dramatic, since the sensing was already pretty good even with the slower V1 scan rate, but you might notice a little better precision in tricky skill shots.

Keyboard keys: button inputs can now be mapped to keyboard keys. The joystick button option is still available as well, of course. Keyboard keys have the advantage of being closer to universal for PC pinball software: some pinball software can be set up to take joystick input, but nearly all PC pinball emulators can take keyboard input, and nearly all of them use the same key mappings.

Local shift button: one physical button can be designed as the local shift button. This works like a Shift button on a keyboard, but with cabinet buttons. It allows each physical button on the cabinet to have two PC keys assigned, one normal and one shifted. Hold down the local shift button, then press another key, and the other key's shifted key mapping is sent to the PC. The shift button can have a regular key mapping of its own as well, so it can do double duty. The shift feature lets you access more functions without cluttering your cabinet with extra buttons. It's especially nice for less frequently used functions like adjusting the volume or activating night mode.

Night mode: the output controller has a new "night mode" option, which lets you turn off all of your noisy devices with a single button, switch, or PC command. You can designate individual ports as noisy or not. Night mode only disables the noisemakers, so you still get the benefit of your flashers, button lights, and other quiet devices. This lets you play late into the night without disturbing your housemates or neighbors.

Gamma correction: you can designate individual output ports for gamma correction. This adjusts the intensity level of an output to make it match the way the human eye perceives brightness, so that fades and color mixes look more natural in lighting devices. You can apply this to individual ports, so that it only affects ports that actually have lights of some kind attached.

IR Remote Control: the controller software can transmit and/or receive IR remote control commands if you attach appropriate parts (an IR LED to send, an IR sensor chip to receive). This can be used to turn on your TV(s) when the system powers on, if they don't turn on automatically, and for any other functions you can think of requiring IR send/receive capabilities. You can assign IR commands to cabinet buttons, so that pressing a button on your cabinet sends a remote control command from the attached IR LED, and you can have the controller generate virtual key presses on your PC in response to received IR commands. If you have the IR sensor attached, the system can use it to learn commands from your existing remotes.

Yet more USB fixes: I've been gradually finding and fixing USB bugs in the mbed library for months now. This version has all of the fixes of the last couple of releases, of course, plus some new ones. It also has a new "last resort" feature, since there always seems to be "just one more" USB bug. The last resort is that you can tell the device to automatically reboot itself if it loses the USB connection and can't restore it within a given time limit.

More Downloads

  • Custom VP builds: I created modified versions of Visual Pinball 9.9 and Physmod5 that you might want to use in combination with this controller. The modified versions have special handling for plunger calibration specific to the Pinscape Controller, as well as some enhancements to the nudge physics. If you're not using the plunger, you might still want it for the nudge improvements. The modified version also works with any other input controller, so you can get the enhanced nudging effects even if you're using a different plunger/nudge kit. The big change in the modified versions is a "filter" for accelerometer input that's designed to make the response to cabinet nudges more realistic. It also makes the response more subdued than in the standard VP, so it's not to everyone's taste. The downloads include both the updated executables and the source code changes, in case you want to merge the changes into your own custom version(s).

    Note! These features are now standard in the official VP releases, so you don't need my custom builds if you're using 9.9.1 or later and/or VP 10. I don't think there's any reason to use my versions instead of the latest official ones, and in fact I'd encourage you to use the official releases since they're more up to date, but I'm leaving my builds available just in case. In the official versions, look for the checkbox "Enable Nudge Filter" in the Keys preferences dialog. My custom versions don't include that checkbox; they just enable the filter unconditionally.
  • Output circuit shopping list: This is a saved shopping cart at mouser.com with the parts needed to build one copy of the high-power output circuit for the LedWiz emulator feature, for use with the standalone KL25Z (that is, without the expansion boards). The quantities in the cart are for one output channel, so if you want N outputs, simply multiply the quantities by the N, with one exception: you only need one ULN2803 transistor array chip for each eight output circuits. If you're using the expansion boards, you won't need any of this, since the boards provide their own high-power outputs.
  • Cary Owens' optical sensor housing: A 3D-printable design for a housing/mounting bracket for the optical plunger sensor, designed by Cary Owens. This makes it easy to mount the sensor.
  • Lemming77's potentiometer mounting bracket and shooter rod connecter: Sketchup designs for 3D-printable parts for mounting a slide potentiometer as the plunger sensor. These were designed for a particular slide potentiometer that used to be available from an Aliexpress.com seller but is no longer listed. You can probably use this design as a starting point for other similar devices; just check the dimensions before committing the design to plastic.

Copyright and License

The Pinscape firmware is copyright 2014, 2021 by Michael J Roberts. It's released under an MIT open-source license. See License.

Warning to VirtuaPin Kit Owners

This software isn't designed as a replacement for the VirtuaPin plunger kit's firmware. If you bought the VirtuaPin kit, I recommend that you don't install this software. The KL25Z can only run one firmware program at a time, so if you install the Pinscape firmware on your KL25Z, it will replace and erase your existing VirtuaPin proprietary firmware. If you do this, the only way to restore your VirtuaPin firmware is to physically ship the KL25Z back to VirtuaPin and ask them to re-flash it. They don't allow you to do this at home, and they don't even allow you to back up your firmware, since they want to protect their proprietary software from copying. For all of these reasons, if you want to run the Pinscape software, I strongly recommend that you buy a "blank" retail KL25Z to use with Pinscape. They only cost about $15 and are available at several online retailers, including Amazon, Mouser, and eBay. The blank retail boards don't come with any proprietary firmware pre-installed, so installing Pinscape won't delete anything that you paid extra for.

With those warnings in mind, if you're absolutely sure that you don't mind permanently erasing your VirtuaPin firmware, it is at least possible to use Pinscape as a replacement for the VirtuaPin firmware. Pinscape uses the same button wiring conventions as the VirtuaPin setup, so you can keep your buttons (although you'll have to update the GPIO pin mappings in the Config Tool to match your physical wiring). As of the June, 2021 firmware, the Vishay VCNL4010 plunger sensor that comes with the VirtuaPin v3 plunger kit is supported, so you can also keep your plunger, if you have that chip. (You should check to be sure that's the sensor chip you have before committing to this route, if keeping the plunger sensor is important to you. The older VirtuaPin plunger kits came with different IR sensors that the Pinscape software doesn't handle.)

Revision:
17:ab3cec0c8bf4
Parent:
16:c35f905c3311
Child:
18:5e890ebd0023
--- a/main.cpp	Mon Dec 29 19:27:52 2014 +0000
+++ b/main.cpp	Fri Feb 27 04:14:04 2015 +0000
@@ -19,96 +19,81 @@
 //
 // Pinscape Controller
 //
-// "Pinscape" is the name of my custom-built virtual pinball cabinet.  I wrote this
-// software to perform a number of tasks that I needed for my cabinet.  It runs on a
-// Freescale KL25Z microcontroller, which is a small and inexpensive device that
-// attaches to the host PC via USB and can interface with numerous types of external
-// hardware.
+// "Pinscape" is the name of my custom-built virtual pinball cabinet, so I call this
+// software the Pinscape Controller.  I wrote it to handle several tasks that I needed
+// for my cabinet.  It runs on a Freescale KL25Z microcontroller, which is a small and 
+// inexpensive device that attaches to the cabinet PC via a USB cable, and can attach
+// via custom wiring to sensors, buttons, and other devices in the cabinet.
 //
-// I designed the software and hardware in this project especially for Pinscape, but 
-// it uses standard interfaces in Windows and Visual Pinball, so it should be
-// readily usable in anyone else's VP-based cabinet.  I've tried to document the
-// hardware in enough detail for anyone else to duplicate the entire project, and
-// the full software is open source.
+// I designed the software and hardware in this project especially for my own
+// cabinet, but it uses standard interfaces in Windows and Visual Pinball, so it should
+// work in any VP-based cabinet, as long as you're using the usual VP software suite.  
+// I've tried to document the hardware in enough detail for anyone else to duplicate 
+// the entire project, and the full software is open source.
 //
-// The device appears to the host computer as a USB joystick.  This works with the
-// standard Windows joystick device drivers, so there's no need to install any
-// software on the PC - Windows should recognize it as a joystick when you plug
-// it in and shouldn't ask you to install anything.  If you bring up the control
-// panel for USB Game Controllers, this device will appear as "Pinscape Controller".
-// *Don't* do any calibration with the Windows control panel or third-part 
-// calibration tools.  The device calibrates itself automatically for the
-// accelerometer data, and has its own special calibration procedure for the
-// plunger (see below).
-//
-// The controller provides the following functions.  It should be possible to use
-// any subet of the features without using all of them.  External hardware for any
-// particular function can simply be omitted if that feature isn't needed.
+// The Freescale board appears to the host PC as a standard USB joystick.  This works 
+// with the built-in Windows joystick device drivers, so there's no need to install any
+// new drivers or other software on the PC.  Windows should recognize the Freescale
+// as a joystick when you plug it into the USB port, and Windows shouldn't ask you to 
+// install any drivers.  If you bring up the Windows control panel for USB Game 
+// Controllers, this device will appear as "Pinscape Controller".  *Don't* do any 
+// calibration with the Windows control panel or third-part calibration tools.  The 
+// software calibrates the accelerometer portion automatically, and has its own special
+// calibration procedure for the plunger sensor, if you're using that (see below).
 //
-//  - Nudge sensing via the KL25Z's on-board accelerometer.  Nudge accelerations are
-//    processed into a physics model of a rolling ball, and changes to the ball's
-//    motion are sent to the host computer via the joystick interface.  This is designed
-//    especially to work with Visuall Pinball's nudge handling to produce realistic 
-//    on-screen results in VP.  By doing some physics modeling right on the device, 
-//    rather than sending raw accelerometer data to VP, we can produce better results
-//    using our awareness of the real physical parameters of a pinball cabinet.
-//    VP's nudge handling has to be more generic, so it can't make the same sorts
-//    of assumptions that we can about the dynamics of a real cabinet.
+// This software provides a whole bunch of separate features.  You can use any of these 
+// features individually or all together.  If you're not using a particular feature, you
+// can simply omit the extra wiring and/or hardware for that feature.  You can use
+// the nudging feature by itself without any extra hardware attached, since the
+// accelerometer is built in to the KL25Z board.
 //
-//    The nudge data reports are compatible with the built-in Windows USB joystick 
-//    drivers and with VP's own joystick input scheme, so the nudge sensing is almost 
-//    plug-and-play.  There are no Windiows drivers to install, and the only VP work 
-//    needed is to customize a few global preference settings.
+//  - Nudge sensing via the KL25Z's on-board accelerometer.  Nudging the cabinet
+//    causes small accelerations that the accelerometer can detect; these are sent to
+//    Visual Pinball via the joystick interface so that VP can simulate the effect
+//    of the real physical nudges on its simulated ball.  VP has native handling for
+//    this type of input, so all you have to do is set some preferences in VP to tell 
+//    it that an accelerometer is attached.
 //
 //  - Plunger position sensing via an attached TAOS TSL 1410R CCD linear array sensor.  
-//    The sensor must be wired to a particular set of I/O ports on the KL25Z, and must 
-//    be positioned adjacent to the plunger with proper lighting.  The physical and
-//    electronic installation details are desribed in the project documentation.  We read 
-//    the CCD to determine how far back the plunger is pulled, and report this to Visual 
-//    Pinball via the joystick interface.  As with the nudge data, this is all nearly
-//    plug-and-play, in that it works with the default Windows USB drivers and works 
-//    with the existing VP handling for analog plunger input.  A few VP settings are
-//    needed to tell VP to allow the plunger.
+//    To use this feature, you need to buy the TAOS device (it's not built in to the
+//    KL25Z, obviously), wire it to the KL25Z (5 wire connections between the two
+//    devices are required), and mount the TAOS sensor in your cabinet so that it's
+//    positioned properly to capture images of the physical plunger shooter rod.
+//
+//    The physical mounting and wiring details are desribed in the project 
+//    documentation.  
+//
+//    If the CCD is attached, the software constantly captures images from the CCD
+//    and analyzes them to determine how far back the plunger is pulled.  It reports
+//    this to Visual Pinball via the joystick interface.  This allows VP to make the
+//    simulated on-screen plunger track the motion of the physical plunger in real
+//    time.  As with the nudge data, VP has native handling for the plunger input, 
+//    so you just need to set the VP preferences to tell it that an analog plunger 
+//    device is attached.  One caveat, though: although VP itself has built-in 
+//    support for an analog plunger, not all existing tables take advantage of it.  
+//    Many existing tables have their own custom plunger scripting that doesn't
+//    cooperate with the VP plunger input.  All tables *can* be made to work with
+//    the plunger, and in most cases it only requires some simple script editing,
+//    but in some cases it requires some more extensive surgery.
 //
 //    For best results, the plunger sensor should be calibrated.  The calibration
 //    is stored in non-volatile memory on board the KL25Z, so it's only necessary
 //    to do the calibration once, when you first install everything.  (You might
 //    also want to re-calibrate if you physically remove and reinstall the CCD 
-//    sensor or the mechanical plunger, since their alignment might change slightly 
-//    when you put everything back together.)  To calibrate, you have to attach a
-//    momentary switch (e.g., a push-button switch) between one of the KL25Z ground
-//    pins (e.g., jumper J9 pin 12) and PTE29 (J10 pin 9).  Press and hold the
-//    button for about two seconds - the LED on the KL25Z wlil flash blue while
-//    you hold the button, and will turn solid blue when you've held it down long
-//    enough to enter calibration mode.  This mode will last about 15 seconds.
-//    Simply pull the plunger all the way back, hold it for a few moments, and
-//    gradually return it to the starting position.  *Don't* release it - we want
-//    to measure the maximum retracted position and the rest position, but NOT
-//    the maximum forward position when the outer barrel spring is compressed.
-//    After about 15 seconds, the device will save the new calibration settings
-//    to its flash memory, and the LED will return to the regular "heartbeat" 
-//    flashes.  If this is the first time you calibrated, you should observe the
-//    color of the flashes change from yellow/green to blue/green to indicate
-//    that the plunger has been calibrated.
+//    sensor or the mechanical plunger, since their alignment shift change slightly 
+//    when you put everything back together.)  You can optionally install a
+//    dedicated momentary switch or pushbutton to activate the calibration mode;
+//    this is describe in the project documentation.  If you don't want to bother
+//    with the extra button, you can also trigger calibration using the Windows 
+//    setup software, which you can find on the Pinscape project page.
 //
-//    Note that while Visual Pinball itself has good native support for analog 
-//    plungers, most of the VP tables in circulation don't implement the necessary
-//    scripting features to make this work properly.  Therefore, you'll have to do
-//    a little scripting work for each table you download to add the required code
-//    to that individual table.  The work has to be customized for each table, so
-//    I haven't been able to automate this process, but I have tried to reduce it
-//    to a relatively simple recipe that I've documented separately.
-//
-//  - In addition to the CCD sensor, a button should be attached (also described in 
-//    the project documentation) to activate calibration mode for the plunger.  When 
-//    calibration mode is activated, the software reads the plunger position for about 
-//    10 seconds when to note the limits of travel, and uses these limits to ensure
-//    accurate reports to VP that properly report the actual position of the physical
-//    plunger.  The calibration is stored in non-volatile memory on the KL25Z, so it's
-//    only necessary to calibrate once - the calibration will survive power cycling
-//    and reboots of the PC.  It's only necessary to recalibrate if the CCD sensor or
-//    the plunger are removed and reinstalled, since the relative alignment of the
-//    parts could cahnge slightly when reinstalling.
+//    The calibration procedure is described in the project documentation.  Briefly,
+//    when you trigger calibration mode, the software will scan the CCD for about
+//    15 seconds, during which you should simply pull the physical plunger back
+//    all the way, hold it for a moment, and then slowly return it to the rest
+//    position.  (DON'T just release it from the retracted position, since that
+//    let it shoot forward too far.  We want to measure the range from the park
+//    position to the fully retracted position only.)
 //
 //  - Button input wiring.  24 of the KL25Z's GPIO ports are mapped as digital inputs
 //    for buttons and switches.  The software reports these as joystick buttons when
@@ -229,13 +214,20 @@
 #include "FreescaleIAP.h"
 #include "crc32.h"
 
+// our local configuration file
+#include "config.h"
+
 
 // ---------------------------------------------------------------------------
-//
-// Configuration details
+// utilities
+
+// number of elements in an array
+#define countof(x) (sizeof(x)/sizeof((x)[0]))
+
+
+// ---------------------------------------------------------------------------
+// USB device vendor ID, product ID, and version.  
 //
-
-// Our USB device vendor ID, product ID, and version.  
 // We use the vendor ID for the LedWiz, so that the PC-side software can
 // identify us as capable of performing LedWiz commands.  The LedWiz uses
 // a product ID value from 0xF0 to 0xFF; the last four bits identify the
@@ -249,13 +241,6 @@
 // single LedWiz already installed in your cabinet, and you didn't ask for
 // a non-default unit number, your existing LedWiz will be unit 0.
 //
-// We use unit #7 by default.  There doesn't seem to be a requirement that
-// unit numbers be contiguous (DirectOutput Framework and other software
-// seem happy to have units 0 and 7 installed, without 1-6 existing).
-// Marking this unit as #7 should work for almost everybody out of the box;
-// the most common case seems to be to have a single LedWiz installed, and
-// it's probably extremely rare to more than two.
-//
 // Note that the USB_PRODUCT_ID value set here omits the unit number.  We
 // take the unit number from the saved configuration.  We provide a
 // configuration command that can be sent via the USB connection to change
@@ -266,235 +251,29 @@
 const uint16_t USB_VENDOR_ID = 0xFAFA;
 const uint16_t USB_PRODUCT_ID = 0x00F0;
 const uint16_t USB_VERSION_NO = 0x0006;
-const uint8_t DEFAULT_LEDWIZ_UNIT_NUMBER = 0x07;
 
-// Number of pixels we read from the sensor on each frame.  This can be
-// less than the physical pixel count if desired; we'll read every nth
-// piexl if so.  E.g., with a 1280-pixel physical sensor, if npix is 320,
-// we'll read every 4th pixel.  It takes time to read each pixel, so the
-// fewer pixels we read, the higher the refresh rate we can achieve.
-// It's therefore better not to read more pixels than we have to.
-//
-// VP seems to have an internal resolution in the 8-bit range, so there's
-// no apparent benefit to reading more than 128-256 pixels when using VP.
-// Empirically, 160 pixels seems about right.  The overall travel of a
-// standard pinball plunger is about 3", so 160 pixels gives us resolution
-// of about 1/50".  This seems to take full advantage of VP's modeling
-// ability, and is probably also more precise than a human player's
-// perception of the plunger position.
-const int npix = 160;
-
-// On-board RGB LED elements - we use these for diagnostic displays.
-DigitalOut ledR(LED1), ledG(LED2), ledB(LED3);
-
-// calibration button - switch input and LED output
-DigitalIn calBtn(PTE29);
-DigitalOut calBtnLed(PTE23);
-
-// Joystick button input pin assignments.  You can wire up to
-// 32 GPIO ports to buttons (equipped with momentary switches).
-// Connect each switch between the desired GPIO port and ground
-// (J9 pin 12 or 14).  When the button is pressed, we'll tell the
-// host PC that the corresponding joystick button is pressed.  We
-// debounce the keystrokes in software, so you can simply wire
-// directly to pushbuttons with no additional external hardware.
-//
-// Note that we assign 24 buttons by default, even though the USB
-// joystick interface can handle up to 32 buttons.  VP itself only
-// allows mapping of up to 24 buttons in the preferences dialog 
-// (although it can recognize 32 buttons internally).  If you want 
-// more buttons, you can reassign pins that are assigned by default
-// as LedWiz outputs.  To reassign a pin, find the pin you wish to
-// reassign in the LedWizPortMap array below, and change the pin name 
-// there to NC (for Not Connected).  You can then change one of the
-// "NC" entries below to the reallocated pin name.  The limit is 32
-// buttons total.
-//
-// Note: PTD1 (pin J2-12) should NOT be assigned as a button input,
-// as this pin is physically connected on the KL25Z to the on-board
-// indicator LED's blue segment.  This precludes any other use of
-// the pin.
-PinName buttonMap[] = {
-    PTC2,      // J10 pin 10, joystick button 1
-    PTB3,      // J10 pin 8,  joystick button 2
-    PTB2,      // J10 pin 6,  joystick button 3
-    PTB1,      // J10 pin 4,  joystick button 4
-    
-    PTE30,     // J10 pin 11, joystick button 5
-    PTE22,     // J10 pin 5,  joystick button 6
-    
-    PTE5,      // J9 pin 15,  joystick button 7
-    PTE4,      // J9 pin 13,  joystick button 8
-    PTE3,      // J9 pin 11,  joystick button 9
-    PTE2,      // J9 pin 9,   joystick button 10
-    PTB11,     // J9 pin 7,   joystick button 11
-    PTB10,     // J9 pin 5,   joystick button 12
-    PTB9,      // J9 pin 3,   joystick button 13
-    PTB8,      // J9 pin 1,   joystick button 14
-    
-    PTC12,     // J2 pin 1,   joystick button 15
-    PTC13,     // J2 pin 3,   joystick button 16
-    PTC16,     // J2 pin 5,   joystick button 17
-    PTC17,     // J2 pin 7,   joystick button 18
-    PTA16,     // J2 pin 9,   joystick button 19
-    PTA17,     // J2 pin 11,  joystick button 20
-    PTE31,     // J2 pin 13,  joystick button 21
-    PTD6,      // J2 pin 17,  joystick button 22
-    PTD7,      // J2 pin 19,  joystick button 23
-    
-    PTE1,      // J2 pin 20,  joystick button 24
-
-    NC,        // not used,   joystick button 25
-    NC,        // not used,   joystick button 26
-    NC,        // not used,   joystick button 27
-    NC,        // not used,   joystick button 28
-    NC,        // not used,   joystick button 29
-    NC,        // not used,   joystick button 30
-    NC,        // not used,   joystick button 31
-    NC         // not used,   joystick button 32
-};
-
-// LED-Wiz emulation output pin assignments.  
-//
-// The LED-Wiz protocol allows setting individual intensity levels
-// on all outputs, with 48 levels of intensity.  This can be used
-// to control lamp brightness and motor speeds, among other things.
-// Unfortunately, the KL25Z only has 10 PWM channels, so while we 
-// can support the full complement of 32 outputs, we can only provide 
-// PWM dimming/speed control on 10 of them.  The remaining outputs 
-// can only be switched fully on and fully off - we can't support
-// dimming on these, so they'll ignore any intensity level setting 
-// requested by the host.  Use these for devices that don't have any
-// use for intensity settings anyway, such as contactors and knockers.
-//
-// Ports with pins assigned as "NC" are not connected.  That is,
-// there's no physical pin for that LedWiz port number.  You can
-// send LedWiz commands to turn NC ports on and off, but doing so
-// will have no effect.  The reason we leave some ports unassigned
-// is that we don't have enough physical GPIO pins to fill out the
-// full LedWiz complement of 32 ports.  Many pins are already taken
-// for other purposes, such as button inputs or the plunger CCD
-// interface.
-//
-// The mapping between physical output pins on the KL25Z and the
-// assigned LED-Wiz port numbers is essentially arbitrary - you can
-// customize this by changing the entries in the array below if you
-// wish to rearrange the pins for any reason.  Be aware that some
-// of the physical outputs are already used for other purposes
-// (e.g., some of the GPIO pins on header J10 are used for the
-// CCD sensor - but you can of course reassign those as well by
-// changing the corresponding declarations elsewhere in this module).
-// The assignments we make here have two main objectives: first,
-// to group the outputs on headers J1 and J2 (to facilitate neater
-// wiring by keeping the output pins together physically), and
-// second, to make the physical pin layout match the LED-Wiz port
-// numbering order to the extent possible.  There's one big wrench
-// in the works, though, which is the limited number and discontiguous
-// placement of the KL25Z PWM-capable output pins.  This prevents
-// us from doing the most obvious sequential ordering of the pins,
-// so we end up with the outputs arranged into several blocks.
-// Hopefully this isn't too confusing; for more detailed rationale,
-// read on...
-// 
-// With the LED-Wiz, the host software configuration usually 
-// assumes that each RGB LED is hooked up to three consecutive ports
-// (for the red, green, and blue components, which need to be 
-// physically wired to separate outputs to allow each color to be 
-// controlled independently).  To facilitate this, we arrange the 
-// PWM-enabled outputs so that they're grouped together in the 
-// port numbering scheme.  Unfortunately, these outputs aren't
-// together in a single group in the physical pin layout, so to
-// group them logically in the LED-Wiz port numbering scheme, we
-// have to break up the overall numbering scheme into several blocks.
-// So our port numbering goes sequentially down each column of
-// header pins, but there are several break points where we have
-// to interrupt the obvious sequence to keep the PWM pins grouped
-// logically.
-//
-// In the list below, "pin J1-2" refers to pin 2 on header J1 on
-// the KL25Z, using the standard pin numbering in the KL25Z 
-// documentation - this is the physical pin that the port controls.
-// "LW port 1" means LED-Wiz port 1 - this is the LED-Wiz port
-// number that you use on the PC side (in the DirectOutput config
-// file, for example) to address the port.  PWM-capable ports are
-// marked as such - we group the PWM-capable ports into the first
-// 10 LED-Wiz port numbers.
-//
-// If you wish to reallocate a pin in the array below to some other
-// use, such as a button input port, simply change the pin name in
-// the entry to NC (for Not Connected).  This will disable the given
-// logical LedWiz port number and free up the physical pin.
-//
-// If you wish to reallocate a pin currently assigned to the button
-// input array, simply change the entry for the pin in the buttonMap[]
-// array above to NC (for "not connected"), and plug the pin name into
-// a slot of your choice in the array below.
-//
-// Note: PTD1 (pin J2-12) should NOT be assigned as an LedWiz output,
-// as this pin is physically connected on the KL25Z to the on-board
-// indicator LED's blue segment.  This precludes any other use of
-// the pin.
-// 
-struct {
-    PinName pin;
-    bool isPWM;
-} ledWizPortMap[32] = {
-    { PTA1, true },      // pin J1-2,  LW port 1  (PWM capable - TPM 2.0 = channel 9)
-    { PTA2, true },      // pin J1-4,  LW port 2  (PWM capable - TPM 2.1 = channel 10)
-    { PTD4, true },      // pin J1-6,  LW port 3  (PWM capable - TPM 0.4 = channel 5)
-    { PTA12, true },     // pin J1-8,  LW port 4  (PWM capable - TPM 1.0 = channel 7)
-    { PTA4, true },      // pin J1-10, LW port 5  (PWM capable - TPM 0.1 = channel 2)
-    { PTA5, true },      // pin J1-12, LW port 6  (PWM capable - TPM 0.2 = channel 3)
-    { PTA13, true },     // pin J2-2,  LW port 7  (PWM capable - TPM 1.1 = channel 13)
-    { PTD5, true },      // pin J2-4,  LW port 8  (PWM capable - TPM 0.5 = channel 6)
-    { PTD0, true },      // pin J2-6,  LW port 9  (PWM capable - TPM 0.0 = channel 1)
-    { PTD3, true },      // pin J2-10, LW port 10 (PWM capable - TPM 0.3 = channel 4)
-    { PTD2, false },     // pin J2-8,  LW port 11
-    { PTC8, false },     // pin J1-14, LW port 12
-    { PTC9, false },     // pin J1-16, LW port 13
-    { PTC7, false },     // pin J1-1,  LW port 14
-    { PTC0, false },     // pin J1-3,  LW port 15
-    { PTC3, false },     // pin J1-5,  LW port 16
-    { PTC4, false },     // pin J1-7,  LW port 17
-    { PTC5, false },     // pin J1-9,  LW port 18
-    { PTC6, false },     // pin J1-11, LW port 19
-    { PTC10, false },    // pin J1-13, LW port 20
-    { PTC11, false },    // pin J1-15, LW port 21
-    { PTE0, false },     // pin J2-18, LW port 22
-    { NC, false },       // Not used,  LW port 23
-    { NC, false },       // Not used,  LW port 24
-    { NC, false },       // Not used,  LW port 25
-    { NC, false },       // Not used,  LW port 26
-    { NC, false },       // Not used,  LW port 27
-    { NC, false },       // Not used,  LW port 28
-    { NC, false },       // Not used,  LW port 29
-    { NC, false },       // Not used,  LW port 30
-    { NC, false },       // Not used,  LW port 31
-    { NC, false }        // Not used,  LW port 32
-};
-
-
-// I2C address of the accelerometer (this is a constant of the KL25Z)
-const int MMA8451_I2C_ADDRESS = (0x1d<<1);
-
-// SCL and SDA pins for the accelerometer (constant for the KL25Z)
-#define MMA8451_SCL_PIN   PTE25
-#define MMA8451_SDA_PIN   PTE24
-
-// Digital in pin to use for the accelerometer interrupt.  For the KL25Z,
-// this can be either PTA14 or PTA15, since those are the pins physically
-// wired on this board to the MMA8451 interrupt controller.
-#define MMA8451_INT_PIN   PTA15
 
 // Joystick axis report range - we report from -JOYMAX to +JOYMAX
 #define JOYMAX 4096
 
 
-// ---------------------------------------------------------------------------
-// utilities
+// --------------------------------------------------------------------------
+//
+// Potentiometer configuration
+//
+#ifdef POT_SENSOR_ENABLED
+#define IF_POT(x) x
+#else
+#define IF_POT(x)
+#endif
 
-// number of elements in an array
-#define countof(x) (sizeof(x)/sizeof((x)[0]))
+
+// ---------------------------------------------------------------------------
+//
+// On-board RGB LED elements - we use these for diagnostic displays.
+//
+DigitalOut ledR(LED1), ledG(LED2), ledB(LED3);
+
 
 // ---------------------------------------------------------------------------
 //
@@ -701,48 +480,79 @@
     return buttons;
 }
 
-// Read buttons with debouncing.  We keep a circular buffer
-// of recent input readings.  We'll AND together the status of
-// each button over the past 50ms.  A button that has been on
-// continuously for 50ms will be reported as ON.  All others
-// will be reported as OFF.
+// Read buttons with debouncing.  
+//
+// Debouncing is the process of filtering out transients from button
+// state changes.  When an electrical switch is closed or opened, the
+// signal can have a brief period of instability that makes the switch
+// appear to turn on and off very rapidly.  This is known as "bouncing".
+//
+// To remove the transients, we filter the signal by requiring each 
+// change to stick for at least a minimum interval (we use 50ms).  We
+// keep a short recent history of each button's state for this purpose.
+// If we see a button change state, we ignore the change if we saw the
+// same button make another change within the same interval.
 uint32_t readButtonsDebounced()
 {
     struct reading {
-        int dt;           // time since previous reading
-        uint32_t b;       // button state at this reading
+        // elapsed time between this reading and the previous reading
+        int dt;
+        
+        // Final button state for each button that changed on this
+        // report.  OR this with a new report (after applying the
+        // mask 'm') to carry forward the changes that occurred in
+        // this report to the new report.
+        uint32_t b;
+        
+        // Change mask at this report.  This is a bit mask of the buttons
+        // that *didn't* change on this report.  AND this mask with a
+        // new reading to filter buttons out of the new reading that
+        // changed on this report.
+        uint32_t m;
     };
     static reading readings[8];  // circular buffer of readings
     static int ri = 0;    // reading buffer index (next write position)
+    static int bPrv = 0;  // immediately previous report
         
     // get the write pointer
     reading *r = &readings[ri];
 
     // figure the time since the last reading, and read the raw button state
-    r->dt = buttonTimer.read_ms();
-    uint32_t b = r->b = readButtonsRaw();
+    int ms = r->dt = buttonTimer.read_ms();
+    uint32_t b = readButtonsRaw();
     
     // start timing the next interval
     buttonTimer.reset();
     
-    // AND together readings over 25ms
-    int ms = 0;
-    for (int i = 1 ; i < countof(readings) && ms < 25 ; ++i)
+    // mask out changes for any buttons that changed state within the
+    // past 50ms
+    for (int i = 1 ; i < countof(readings) && ms < 50 ; ++i)
     {
         // find the next prior reading, wrapping in the circular buffer
         int j = ri - i;
         if (j < 0) 
             j = countof(readings) - 1;
-            
         reading *rj = &readings[j];
-        
-        // AND the buttons for this reading
-        b &= rj->b;
-        
-        // count the time
+
+        // For any button that changed state in the prior reading 'rj',
+        // remove any new change and restore it to its 'rj' state.
+        b &= rj->m;
+        b |= rj->b;
+                
+        // add in the time to the next prior report
         ms += rj->dt;
     }
     
+    // figure which buttons changed on this report vs the prior report
+    uint32_t m = b ^ bPrv;
+    
+    // save the change mask and changed button vector in our history entry
+    r->m = ~m;
+    r->b = b & m;
+    
+    // save this as the prior report
+    bPrv = b;
+    
     // advance the write position for next time
     ri += 1;
     if (ri >= countof(readings)) 
@@ -754,88 +564,6 @@
 
 // ---------------------------------------------------------------------------
 //
-// Non-volatile memory (NVM)
-//
-
-// Structure defining our NVM storage layout.  We store a small
-// amount of persistent data in flash memory to retain calibration
-// data when powered off.
-struct NVM
-{
-    // checksum - we use this to determine if the flash record
-    // has been properly initialized
-    uint32_t checksum;
-
-    // signature value
-    static const uint32_t SIGNATURE = 0x4D4A522A;
-    static const uint16_t VERSION = 0x0003;
-    
-    // Is the data structure valid?  We test the signature and 
-    // checksum to determine if we've been properly stored.
-    int valid() const
-    {
-        return (d.sig == SIGNATURE 
-                && d.vsn == VERSION
-                && d.sz == sizeof(NVM)
-                && checksum == CRC32(&d, sizeof(d)));
-    }
-    
-    // save to non-volatile memory
-    void save(FreescaleIAP &iap, int addr)
-    {
-        // update the checksum and structure size
-        checksum = CRC32(&d, sizeof(d));
-        d.sz = sizeof(NVM);
-        
-        // erase the sector
-        iap.erase_sector(addr);
-
-        // save the data
-        iap.program_flash(addr, this, sizeof(*this));
-    }
-    
-    // reset calibration data for calibration mode
-    void resetPlunger()
-    {
-        // set extremes for the calibration data
-        d.plungerMax = 0;
-        d.plungerZero = npix;
-        d.plungerMin = npix;
-    }
-    
-    // stored data (excluding the checksum)
-    struct
-    {
-        // Signature, structure version, and structure size - further verification 
-        // that we have valid initialized data.  The size is a simple proxy for a
-        // structure version, as the most common type of change to the structure as
-        // the software evolves will be the addition of new elements.  We also
-        // provide an explicit version number that we can update manually if we
-        // make any changes that don't affect the structure size but would affect
-        // compatibility with a saved record (e.g., swapping two existing elements).
-        uint32_t sig;
-        uint16_t vsn;
-        int sz;
-        
-        // has the plunger been manually calibrated?
-        int plungerCal;
-        
-        // plunger calibration min and max
-        int plungerMin;
-        int plungerZero;
-        int plungerMax;
-        
-        // is the CCD enabled?
-        int ccdEnabled;
-        
-        // LedWiz unit number
-        uint8_t ledWizUnitNo;
-    } d;
-};
-
-
-// ---------------------------------------------------------------------------
-//
 // Customization joystick subbclass
 //
 
@@ -904,6 +632,19 @@
 // of nudging, say).
 //
 
+// I2C address of the accelerometer (this is a constant of the KL25Z)
+const int MMA8451_I2C_ADDRESS = (0x1d<<1);
+
+// SCL and SDA pins for the accelerometer (constant for the KL25Z)
+#define MMA8451_SCL_PIN   PTE25
+#define MMA8451_SDA_PIN   PTE24
+
+// Digital in pin to use for the accelerometer interrupt.  For the KL25Z,
+// this can be either PTA14 or PTA15, since those are the pins physically
+// wired on this board to the MMA8451 interrupt controller.
+#define MMA8451_INT_PIN   PTA15
+
+
 // accelerometer input history item, for gathering calibration data
 struct AccHist
 {
@@ -1191,6 +932,113 @@
 
 // ---------------------------------------------------------------------------
 //
+// Include the appropriate plunger sensor definition.  This will define a
+// class called PlungerSensor, with a standard interface that we use in
+// the main loop below.  This is *kind of* like a virtual class interface,
+// but it actually defines the methods statically, which is a little more
+// efficient at run-time.  There's no need for a true virtual interface
+// because we don't need to be able to change sensor types on the fly.
+//
+
+#ifdef ENABLE_CCD_SENSOR
+#include "ccdSensor.h"
+#elif ENABLE_POT_SENSOR
+#include "potSensor.h"
+#else
+#include "nullSensor.h"
+#endif
+
+
+// ---------------------------------------------------------------------------
+//
+// Non-volatile memory (NVM)
+//
+
+// Structure defining our NVM storage layout.  We store a small
+// amount of persistent data in flash memory to retain calibration
+// data when powered off.
+struct NVM
+{
+    // checksum - we use this to determine if the flash record
+    // has been properly initialized
+    uint32_t checksum;
+
+    // signature value
+    static const uint32_t SIGNATURE = 0x4D4A522A;
+    static const uint16_t VERSION = 0x0003;
+    
+    // Is the data structure valid?  We test the signature and 
+    // checksum to determine if we've been properly stored.
+    int valid() const
+    {
+        return (d.sig == SIGNATURE 
+                && d.vsn == VERSION
+                && d.sz == sizeof(NVM)
+                && checksum == CRC32(&d, sizeof(d)));
+    }
+    
+    // save to non-volatile memory
+    void save(FreescaleIAP &iap, int addr)
+    {
+        // update the checksum and structure size
+        checksum = CRC32(&d, sizeof(d));
+        d.sz = sizeof(NVM);
+        
+        // erase the sector
+        iap.erase_sector(addr);
+
+        // save the data
+        iap.program_flash(addr, this, sizeof(*this));
+    }
+    
+    // reset calibration data for calibration mode
+    void resetPlunger()
+    {
+        // set extremes for the calibration data
+        d.plungerMax = 0;
+        d.plungerZero = npix;
+        d.plungerMin = npix;
+    }
+    
+    // stored data (excluding the checksum)
+    struct
+    {
+        // Signature, structure version, and structure size - further verification 
+        // that we have valid initialized data.  The size is a simple proxy for a
+        // structure version, as the most common type of change to the structure as
+        // the software evolves will be the addition of new elements.  We also
+        // provide an explicit version number that we can update manually if we
+        // make any changes that don't affect the structure size but would affect
+        // compatibility with a saved record (e.g., swapping two existing elements).
+        uint32_t sig;
+        uint16_t vsn;
+        int sz;
+        
+        // has the plunger been manually calibrated?
+        int plungerCal;
+        
+        // Plunger calibration min, zero, and max.  The zero point is the 
+        // rest position (aka park position), where it's in equilibrium between 
+        // the main spring and the barrel spring.  It can travel a small distance
+        // forward of the rest position, because the barrel spring can be
+        // compressed by the user pushing on the plunger or by the momentum
+        // of a release motion.  The minimum is the maximum forward point where
+        // the barrel spring can't be compressed any further.
+        int plungerMin;
+        int plungerZero;
+        int plungerMax;
+        
+        // is the plunger sensor enabled?
+        int plungerEnabled;
+        
+        // LedWiz unit number
+        uint8_t ledWizUnitNo;
+    } d;
+};
+
+
+// ---------------------------------------------------------------------------
+//
 // Main program loop.  This is invoked on startup and runs forever.  Our
 // main work is to read our devices (the accelerometer and the CCD), process
 // the readings into nudge and plunger position data, and send the results
@@ -1239,11 +1087,11 @@
         cfg.d.sig = cfg.SIGNATURE;
         cfg.d.vsn = cfg.VERSION;
         cfg.d.plungerCal = 0;
-        cfg.d.plungerZero = 0;
-        cfg.d.plungerMin = 0;
-        cfg.d.plungerMax = npix;
+        cfg.d.plungerMin = 0;        // assume we can go all the way forward...
+        cfg.d.plungerMax = npix;     // ...and all the way back
+        cfg.d.plungerZero = npix/6;  // the rest position is usually around 1/2" back
         cfg.d.ledWizUnitNo = DEFAULT_LEDWIZ_UNIT_NUMBER;
-        cfg.d.ccdEnabled = true;
+        cfg.d.plungerEnabled = true;
     }
     
     // Create the joystick USB client.  Note that we use the LedWiz unit
@@ -1252,6 +1100,15 @@
         USB_VENDOR_ID, 
         USB_PRODUCT_ID | cfg.d.ledWizUnitNo,
         USB_VERSION_NO);
+        
+    // last report timer - we use this to throttle reports, since VP
+    // doesn't want to hear from us more than about every 10ms
+    Timer reportTimer;
+    reportTimer.start();
+
+    // initialize the calibration buttons, if present
+    DigitalIn *calBtn = (CAL_BUTTON_PIN == NC ? 0 : new DigitalIn(CAL_BUTTON_PIN));
+    DigitalOut *calBtnLed = (CAL_BUTTON_LED == NC ? 0 : new DigitalOut(CAL_BUTTON_LED));
 
     // plunger calibration button debounce timer
     Timer calBtnTimer;
@@ -1278,32 +1135,108 @@
     // create the accelerometer object
     Accel accel(MMA8451_SCL_PIN, MMA8451_SDA_PIN, MMA8451_I2C_ADDRESS, MMA8451_INT_PIN);
     
-    // create the CCD array object
-    TSL1410R ccd(PTE20, PTE21, PTB0);
+    // last accelerometer report, in joystick units (we report the nudge
+    // acceleration via the joystick x & y axes, per the VP convention)
+    int x = 0, y = 0;
+    
+    // create our plunger sensor object
+    PlungerSensor plungerSensor;
+
+    // last plunger report position, in 'npix' normalized pixel units
+    int pos = 0;
+    
+    // last plunger report, in joystick units (we report the plunger as the
+    // "z" axis of the joystick, per the VP convention)
+    int z = 0;
+    
+    // most recent prior plunger readings, for tracking release events(z0 is
+    // reading just before the last one we reported, z1 is the one before that, 
+    // z2 the next before that)
+    int z0 = 0, z1 = 0, z2 = 0;
+    
+    // Simulated "bounce" position when firing.  We model the bounce off of
+    // the barrel spring when the plunger is released as proportional to the
+    // distance it was retracted just before being released.
+    int zBounce = 0;
     
-    // last accelerometer report, in mouse coordinates
-    int x = 0, y = 0, z = 0;
+    // Simulated Launch Ball button state.  If a "ZB Launch Ball" port is
+    // defined for our LedWiz port mapping, any time that port is turned ON,
+    // we'll simulate pushing the Launch Ball button if the player pulls 
+    // back and releases the plunger, or simply pushes on the plunger from
+    // the rest position.  This allows the plunger to be used in lieu of a
+    // physical Launch Ball button for tables that don't have plungers.
+    //
+    // States:
+    //   0 = default
+    //   1 = cocked (plunger has been pulled back about 1" from state 0)
+    //   2 = uncocked (plunger is pulled back less than 1" from state 1)
+    //   3 = launching (plunger has been released from state 1 or 2, or 
+    //       pushed forward about 1/4" from state 0)
+    //   4 = launching, plunger is no longer pushed forward
+    int lbState = 0;
     
-    // previous two plunger readings, for "debouncing" the results (z0 is
-    // the most recent, z1 is the one before that)
-    int z0 = 0, z1 = 0, z2 = 0;
+    // Time since last lbState transition.  Some of the states are time-
+    // sensitive.  In the "uncocked" state, we'll return to state 0 if
+    // we remain in this state for more than a few milliseconds, since
+    // it indicates that the plunger is being slowly returned to rest
+    // rather than released.  In the "launching" state, we need to release 
+    // the Launch Ball button after a moment, and we need to wait for 
+    // the plunger to come to rest before returning to state 0.
+    Timer lbTimer;
+    lbTimer.start();
+    
+    // Simulated button states.  This is a vector of button states
+    // for the simulated buttons.  We combine this with the physical
+    // button states on each USB joystick report, so we will report
+    // a button as pressed if either the physical button is being pressed
+    // or we're simulating a press on the button.  This is used for the
+    // simulated Launch Ball button.
+    uint32_t simButtons = 0;
     
     // Firing in progress: we set this when we detect the start of rapid 
     // plunger movement from a retracted position towards the rest position.
-    // The actual plunger spring return speed seems to be too slow for VP, 
-    // so when we detect the start of this motion, we immediately tell VP
-    // to return the plunger to rest, then we monitor the real plunger 
-    // until it atcually stops.
+    //
+    // When we detect a firing event, we send VP a series of synthetic
+    // reports simulating the idealized plunger motion.  The actual physical
+    // motion is much too fast to report to VP; in the time between two USB
+    // reports, the plunger can shoot all the way forward, rebound off of
+    // the barrel spring, bounce back part way, and bounce forward again,
+    // or even do all of this more than once.  This means that sampling the 
+    // physical motion at the USB report rate would create a misleading 
+    // picture of the plunger motion, since our samples would catch the 
+    // plunger at random points in this oscillating motion.  From the 
+    // user's perspective, the physical action that occurred is simply that 
+    // the plunger was released from a particular distance, so it's this 
+    // high-level event that we want to convey to VP.  To do this, we
+    // synthesize a series of reports to convey an idealized version of
+    // the release motion that's perfectly synchronized to the VP reports.  
+    // Essentially we pretend that our USB position samples are exactly 
+    // aligned in time with (1) the point of retraction just before the 
+    // user released the plunger, (2) the point of maximum forward motion 
+    // just after the user released the plunger (the point of maximum 
+    // compression as the plunger bounces off of the barrel spring), and 
+    // (3) the plunger coming to rest at the park position.  This series
+    // of reports is synthetic in the sense that it's not what we actually
+    // see on the CCD at the times of these reports - the true plunger
+    // position is oscillating at high speed during this period.  But at
+    // the same time it conveys a more faithful picture of the true physical
+    // motion to VP, and allows VP to reproduce the true physical motion 
+    // more faithfully in its simulation model, by correcting for the
+    // relatively low sampling rate in the communication path between the
+    // real plunger and VP's model plunger.
+    //
+    // If 'firing' is non-zero, it's the index of our current report in
+    // the synthetic firing report series.
     int firing = 0;
 
     // start the first CCD integration cycle
-    ccd.clear();
+    plungerSensor.init();
     
     // Device status.  We report this on each update so that the host config
     // tool can detect our current settings.  This is a bit mask consisting
     // of these bits:
     //    0x01  -> plunger sensor enabled
-    uint16_t statusFlags = (cfg.d.ccdEnabled ? 0x01 : 0x00);
+    uint16_t statusFlags = (cfg.d.plungerEnabled ? 0x01 : 0x00);
     
     // flag: send a pixel dump after the next read
     bool reportPix = false;
@@ -1366,13 +1299,13 @@
                         
                         // set the configuration parameters from the message
                         cfg.d.ledWizUnitNo = newUnitNo;
-                        cfg.d.ccdEnabled = data[3] & 0x01;
+                        cfg.d.plungerEnabled = data[3] & 0x01;
                         
                         // update the status flags
                         statusFlags = (statusFlags & ~0x01) | (data[3] & 0x01);
                         
                         // if the ccd is no longer enabled, use 0 for z reports
-                        if (!cfg.d.ccdEnabled)
+                        if (!cfg.d.plungerEnabled)
                             z = 0;
                         
                         // save the configuration
@@ -1425,7 +1358,7 @@
         }
        
         // check for plunger calibration
-        if (!calBtn)
+        if (calBtn != 0 && !calBtn->read())
         {
             // check the state
             switch (calBtnState)
@@ -1516,283 +1449,321 @@
         {
             calBtnLit = newCalBtnLit;
             if (calBtnLit) {
-                calBtnLed = 1;
+                if (calBtnLed != 0)
+                    calBtnLed->write(1);
                 ledR = 1;
                 ledG = 1;
                 ledB = 0;
             }
             else {
-                calBtnLed = 0;
+                if (calBtnLed != 0)
+                    calBtnLed->write(0);
                 ledR = 1;
                 ledG = 1;
                 ledB = 1;
             }
         }
         
+        // If the plunger is enabled, and we're not already in a firing event,
+        // and the last plunger reading had the plunger pulled back at least
+        // a bit, watch for plunger release events until it's time for our next
+        // USB report.
+        if (!firing && cfg.d.plungerEnabled && z >= JOYMAX/6)
+        {
+            // monitor the plunger until it's time for our next report
+            while (reportTimer.read_ms() < 15)
+            {
+                // do a fast low-res scan; if it's at or past the zero point,
+                // start a firing event
+                if (plungerSensor.lowResScan() <= cfg.d.plungerZero)
+                    firing = 1;
+            }
+        }
+
         // read the plunger sensor, if it's enabled
-        uint16_t pix[npix];
-        if (cfg.d.ccdEnabled)
+        if (cfg.d.plungerEnabled)
         {
             // start with the previous reading, in case we don't have a
             // clear result on this frame
             int znew = z;
-
-            // read the array
-            ccd.read(pix, npix, ccdReadCB, 0, 3);
-    
-            // get the average brightness at each end of the sensor
-            long avg1 = (long(pix[0]) + long(pix[1]) + long(pix[2]) + long(pix[3]) + long(pix[4]))/5;
-            long avg2 = (long(pix[npix-1]) + long(pix[npix-2]) + long(pix[npix-3]) + long(pix[npix-4]) + long(pix[npix-5]))/5;
-            
-            // figure the midpoint in the brightness; multiply by 3 so that we can
-            // compare sums of three pixels at a time to smooth out noise
-            long midpt = (avg1 + avg2)/2 * 3;
-            
-            // Work from the bright end to the dark end.  VP interprets the
-            // Z axis value as the amount the plunger is pulled: zero is the
-            // rest position, and the axis maximum is fully pulled.  So we 
-            // essentially want to report how much of the sensor is lit,
-            // since this increases as the plunger is pulled back.
-            int si = 1, di = 1;
-            if (avg1 < avg2)
-                si = npix - 2, di = -1;
-    
-            // If the bright end and dark end don't differ by enough, skip this
-            // reading entirely - we must have an overexposed or underexposed frame.
-            // Otherwise proceed with the scan.
-            if (labs(avg1 - avg2) > 0x1000)
+            if (plungerSensor.highResScan(pos))
             {
-                uint16_t *pixp = pix + si;           
-                for (int n = 1 ; n < npix - 1 ; ++n, pixp += di)
+                // We got a new reading.  If we're in calibration mode, use it
+                // to figure the new calibration, otherwise adjust the new reading
+                // for the established calibration.
+                if (calBtnState == 3)
                 {
-                    // if we've crossed the midpoint, report this position
-                    if (long(pixp[-1]) + long(pixp[0]) + long(pixp[1]) < midpt)
-                    {
-                        // note the new position
-                        int pos = n;
+                    // Calibration mode.  If this reading is outside of the current
+                    // calibration bounds, expand the bounds.
+                    if (pos < cfg.d.plungerMin)
+                        cfg.d.plungerMin = pos;
+                    if (pos < cfg.d.plungerZero)
+                        cfg.d.plungerZero = pos;
+                    if (pos > cfg.d.plungerMax)
+                        cfg.d.plungerMax = pos;
                         
-                        // Calibrate, or apply calibration, depending on the mode.
-                        // In either case, normalize to our range.  VP appears to
-                        // ignore negative Z axis values.
-                        if (calBtnState == 3)
-                        {
-                            // calibrating - note if we're expanding the calibration envelope
-                            if (pos < cfg.d.plungerMin)
-                                cfg.d.plungerMin = pos;
-                            if (pos < cfg.d.plungerZero)
-                                cfg.d.plungerZero = pos;
-                            if (pos > cfg.d.plungerMax)
-                                cfg.d.plungerMax = pos;
-                                
-                            // normalize to the full physical range while calibrating
-                            znew = int(round(float(pos)/npix * JOYMAX));
-                        }
-                        else
-                        {
-                            // Running normally - normalize to the calibration range.  Note
-                            // that values below the zero point are allowed - the zero point
-                            // represents the park position, where the plunger sits when at
-                            // rest, but a mechanical plunger has a smmall amount of travel
-                            // in the "push" direction.  We represent forward travel with
-                            // negative z values.
-                            if (pos > cfg.d.plungerMax)
-                                pos = cfg.d.plungerMax;
-                            znew = int(round(float(pos - cfg.d.plungerZero)
-                                / (cfg.d.plungerMax - cfg.d.plungerZero + 1) * JOYMAX));
-                        }
-                        
-                        // done
-                        break;
-                    }
+                    // normalize to the full physical range while calibrating
+                    znew = int(round(float(pos)/npix * JOYMAX));
+                }
+                else
+                {
+                    // Not in calibration mode, so normalize the new reading to the 
+                    // established calibration range.  
+                    //
+                    // Note that negative values are allowed.  Zero represents the
+                    // "park" position, where the plunger sits when at rest.  A mechanical 
+                    // plunger has a smmall amount of travel in the "push" direction,
+                    // since the barrel spring can be compressed slightly.  Negative
+                    // values represent travel in the push direction.
+                    if (pos > cfg.d.plungerMax)
+                        pos = cfg.d.plungerMax;
+                    znew = int(round(float(pos - cfg.d.plungerZero)
+                        / (cfg.d.plungerMax - cfg.d.plungerZero + 1) * JOYMAX));
                 }
             }
 
-            // Determine if the plunger is being fired - i.e., if the player
-            // has just released the plunger from a retracted position.
-            //
-            // We treat firing as an event.  That is, we tell VP when the
-            // plunger is fired, and then stop sending data until the firing
-            // is complete, allowing VP to carry out the firing motion using
-            // its internal model plunger rather than trying to track the
-            // intermediate positions of the mechanical plunger throughout
-            // the firing motion.  This is essential because the firing
-            // motion is too fast for us to track - in the time it takes us
-            // to read one frame, the plunger can make it all the way to the
-            // zero position and bounce back halfway.  Fortunately, the range
-            // of motions for the plunger is limited, so if we see any rapid
-            // change of position toward the rest position, it's reasonably
-            // safe to interpret it as a firing event.  
-            //
-            // This isn't foolproof.  The user can trick us by doing a 
-            // controlled rapid forward push but stopping short of the rest 
-            // position.  We'll misinterpret that as a firing event.  But 
-            // that's not a natural motion that a user would make with a
-            // plunger, so it's probably an acceptable false positive.
-            //
-            // Possible future enhancement: we could add a second physical
-            // sensor that detects when the plunger reaches the zero position
-            // and asserts an interrupt.  In the interrupt handler, set a
-            // flag indicating the zero position signal.  On each scan of
-            // the CCD, also check that flag; if it's set, enter firing
-            // event mode just as we do now.  The key here is that the
-            // secondary sensor would have to be something much faster
-            // than our CCD scan - it would have to react on, say, the
-            // millisecond time scale.  A simple mechanical switch or a
-            // proximity sensor could work.  This would let us detect
-            // with certainty when the plunger physically fires, eliminating
-            // the case where the use can fool us with motion that's fast
-            // enough to look like a release but doesn't actually reach the
-            // starting position.
+            // If we're not already in a firing event, check to see if the
+            // new position is forward of the last report.  If it is, a firing
+            // event might have started during the high-res scan.  This might
+            // seem unlikely given that the scan only takes about 5ms, but that
+            // 5ms represents about 25-30% of our total time between reports,
+            // there's about a 1 in 4 chance that a release starts during a
+            // scan.  
+            if (!firing && z0 > 0 && znew < z0)
+            {
+                // The plunger has moved forward since the previous report.
+                // Watch it for a few more ms to see if we can get a stable
+                // new position.
+                int pos1 = plungerSensor.lowResScan();
+                Timer tw;
+                tw.start();
+                while (tw.read_ms() < 6)
+                {
+                    // if we've crossed the rest position, it's a firing event
+                    if (pos1 < cfg.d.plungerZero)
+                    {
+                        firing = 1;
+                        break;
+                    }
+                    
+                    // read the new position
+                    int pos2 = plungerSensor.lowResScan();
+                    
+                    // if it's stable, stop looping
+                    if (abs(pos2 - pos1) < int(npix/(3.2*8)))
+                        break;
+                        
+                    // the new reading is now the prior reading
+                    pos1 = pos2;
+                }
+            }
+            
+            // Check for a simulated Launch Ball button press, if enabled
+            if (ZBLaunchBallPort != 0 && wizOn[ZBLaunchBallPort-1])
+            {
+                int newState = lbState;
+                switch (lbState)
+                {
+                case 0:
+                    // Base state.  If the plunger is pulled back by an inch
+                    // or more, go to "cocked" state.  If the plunger is pushed
+                    // forward by 1/4" or more, go to "launch" state.
+                    if (znew >= JOYMAX/3)
+                        newState = 1;
+                    else if (znew < -JOYMAX/12)
+                        newState = 3;
+                    break;
+                    
+                case 1:
+                    // Cocked state.  If a firing event is now in progress,
+                    // go to "launch" state.  Otherwise, if the plunger is less
+                    // than 1" retracted, go to "uncocked" state - the player
+                    // might be slowly returning the plunger to rest so as not
+                    // to trigger a launch.
+                    if (firing || znew <= 0)
+                        newState = 3;
+                    else if (znew < JOYMAX/3)
+                        newState = 2;
+                    break;
+                    
+                case 2:
+                    // Uncocked state.  If the plunger is more than an inch
+                    // retracted, return to cocked state.  If we've been in
+                    // the uncocked state for more than half a second, return
+                    // to the base state.
+                    if (znew >= JOYMAX/3)
+                        newState = 1;
+                    else if (lbTimer.read_ms() > 500)
+                        newState = 0;
+                    break;
+                    
+                case 3:
+                    // Launch state.  If the plunger is no longer pushed
+                    // forward, switch to launch rest state.
+                    if (znew > -JOYMAX/24)
+                        newState = 4;
+                    break;    
+                    
+                case 4:
+                    // Launch rest state.  If the plunger is pushed forward
+                    // again, switch back to launch state.  If not, and we've
+                    // been in this state for at least 200ms, return to the
+                    // default state.
+                    if (znew < -JOYMAX/12)
+                        newState = 3;
+                    else if (lbTimer.read_ms() > 200)
+                        newState = 0;                    
+                    break;
+                }
+                
+                // change states if desired
+                if (newState != lbState)
+                {
+                    // if we're entering Launch state, press the Launch Ball button
+                    if (newState == 3 && lbState != 4)
+                        simButtons |= (1 << (LaunchBallButton - 1));
+                        
+                    // if we're switching to state 0, release the button
+                    if (newState == 0)
+                        simButtons &= ~(1 << (LaunchBallButton - 1));
+                    
+                    // switch to the new state
+                    lbState = newState;
+                    
+                    // start timing in the new state
+                    lbTimer.reset();
+                }
+            }
+                
+            // If a firing event is in progress, generate synthetic reports to 
+            // describe an idealized version of the plunger motion to VP rather 
+            // than reporting the actual physical plunger position.
             //
-            // To detremine when a firing even occurs, we watch for rapid
-            // motion from a retracted position towards the rest position -
-            // that is, large position changes in the negative direction over
-            // a couple of consecutive readings.  When we see a rapid move
-            // toward zero, we set our internal 'firing' flag, immediately
-            // report to VP that the plunger has returned to the zero 
-            // position, and then suspend reports until the mechanical
-            // readings indicate that the plunger has come to rest (indicated
-            // by several readings in a row at roughly the same position).
+            // We use the synthetic reports during a release event because the
+            // physical plunger motion when released is too fast for VP to track.
+            // VP only syncs its internal physics model with the outside world 
+            // about every 10ms.  In that amount of time, the plunger moves
+            // fast enough when released that it can shoot all the way forward,
+            // bounce off of the barrel spring, and rebound part of the way
+            // back.  The result is the classic analog-to-digital problem of
+            // sample aliasing.  If we happen to time our sample during the
+            // release motion so that we catch the plunger at the peak of a
+            // bounce, the digital signal incorrectly looks like the plunger
+            // is moving slowly forward - VP thinks we went from fully
+            // retracted to half retracted in the sample interval, whereas
+            // we actually traveled all the way forward and half way back,
+            // so the speed VP infers is about 1/3 of the actual speed.
             //
-            // Tolerance for firing is 1/3 of the current pull distance, or
-            // about 1/2", whichever is greater.  Making this value too small
-            // makes for too many false positives.  Empirically, 1/4" is too
-            // twitchy, so set a floor at about 1/2".  But we can be less
-            // sensitive the further back the plunger is pulled, since even
-            // a long pull will snap back quickly.  Note that JOYMAX always
-            // corresponds to about 3", no matter how many pixels we're
-            // reading, since the physical sensor is about 3" long; so we
-            // factor out the pixel count calculate (approximate) physical
-            // distances based on the normalized axis range.
-            // 
-            // Firing pattern: when firing, don't simply report a solid 0,
-            // but instead report a series of pseudo-bouces.  This looks
-            // more realistic, beacause the real plunger is also bouncing
-            // around during this time.  To get maximum firing power in
-            // the simulation, though, our pseudo-bounces are tiny cmopared
-            // to the real thing.
-            const int restTol = JOYMAX/24;
-            int fireTol = z/3 > JOYMAX/6 ? z/3 : JOYMAX/6;
-            static const int firePattern[] = { 
-                -JOYMAX/12, -JOYMAX/12, -JOYMAX/12, 
-            };
-            if (firing != 0)
+            // To correct this, we take advantage of our ability to sample 
+            // the CCD image several times in the course of a VP report.  If
+            // we catch the plunger near the origin after we've seen it
+            // retracted, we go into Release Event mode.  During this mode,
+            // we stop reporting the true physical plunger position, and
+            // instead report an idealized pattern: we report the plunger
+            // immediately shooting forward to a position in front of the
+            // park position that's in proportion to how far back the plunger
+            // was just before the release, and we then report it stationary
+            // at the park position.  We continue to report the stationary
+            // park position until the actual physical plunger motion has
+            // stabilized on a new position.  We then exit Release Event
+            // mode and return to reporting the true physical position.
+            if (firing)
             {
-                // Firing in progress - we've already told VP to send its
-                // model plunger all the way back to the rest position, so
-                // send no further reports until the mechanical plunger
-                // actually comes to rest somewhere.
-                if (abs(z0 - z2) < restTol && abs(znew - z2) < restTol)
+                // Firing in progress.  Keep reporting the park position
+                // until the physical plunger position comes to rest.
+                const int restTol = JOYMAX/24;
+                if (firing == 1)
                 {
-                    // the plunger is back at rest - firing is done
-                    firing = 0;
-                    
-                    // resume normal reporting
-                    z = z2;
+                    // For the first couple of frames, show the plunger shooting
+                    // forward past the zero point, to simulate the momentum carrying
+                    // it forward to bounce off of the barrel spring.  Show the 
+                    // bounce as proportional to the distance it was retracted
+                    // in the prior report.
+                    z = zBounce = -z0/6;
+                    ++firing;
                 }
-                else if (firing < countof(firePattern))
+                else if (firing == 2)
                 {
-                    // firing - report the next position in the pseudo-bounce 
-                    // pattern
-                    z = firePattern[firing++];
+                    // second frame - keep the bounce a little longer
+                    z = zBounce;
+                    ++firing;
+                }
+                else if (firing > 4
+                    && abs(znew - z0) < restTol
+                    && abs(znew - z1) < restTol 
+                    && abs(znew - z2) < restTol)
+                {
+                    // The physical plunger has come to rest.  Exit firing
+                    // mode and resume reporting the actual position.
+                    firing = false;
+                    z = znew;
                 }
                 else
                 {
-                    // firing, out of pseudo-bounce items - just report the
-                    // rest position
+                    // until the physical plunger comes to rest, simply 
+                    // report the park position
                     z = 0;
+                    ++firing;
                 }
             }
-            else if (z0 < z2 && z1 < z2 && znew < z2
-                     && (z0 < z2 - fireTol 
-                         || z1 < z2 - fireTol
-                         || znew < z2 - fireTol))
-            {
-                // Big jumps toward rest position in last two readings - 
-                // firing has begun.  Report an immediate return to the
-                // rest position, and send no further reports until the
-                // physical plunger has come to rest.  This effectively
-                // detaches VP's model plunger from the real world for
-                // the duration of the spring return, letting VP evolve
-                // its model without trying to synchronize with the
-                // mechanical version.  The release motion is too fast
-                // for that to work well; we can't take samples quickly
-                // enough to get prcise velocity or acceleration
-                // readings.  It's better to let VP figure the speed
-                // and acceleration through modeling.  Plus, that lets
-                // each virtual table set the desired parameters for its
-                // virtual plunger, rather than imposing the actual
-                // mechanical charateristics of the physical plunger on
-                // every table.
-                firing = 1;
-                
-                // report the first firing pattern position
-                z = firePattern[0];
-            }
             else
             {
-                // everything normal; report the 3rd recent position on
-                // tape delay
-                z = z2;
+                // not in firing mode - report the true physical position
+                z = znew;
             }
-        
-            // shift in the new reading
+
+            // shift the new reading into the recent history buffer
             z2 = z1;
             z1 = z0;
             z0 = znew;
         }
-        else
-        {
-            // plunger disabled - pause 10ms to throttle updates to a
-            // reasonable pace
-            wait_ms(10);
-        }
 
-        // read the accelerometer
-        int xa, ya;
-        accel.get(xa, ya);
-        
-        // confine the results to our joystick axis range
-        if (xa < -JOYMAX) xa = -JOYMAX;
-        if (xa > JOYMAX) xa = JOYMAX;
-        if (ya < -JOYMAX) ya = -JOYMAX;
-        if (ya > JOYMAX) ya = JOYMAX;
-        
-        // store the updated accelerometer coordinates
-        x = xa;
-        y = ya;
-        
         // update the buttons
         uint32_t buttons = readButtonsDebounced();
-        
-        // Send the status report.  Note that the nominal x and y axes
-        // are reversed - this makes it more intuitive to set up in VP.
-        // If we mount the Freesale card flat on the floor of the cabinet
-        // with the USB connectors facing the front of the cabinet, this
-        // arrangement of our nominal axes aligns with VP's standard
-        // setting, so that we can configure VP with X Axis = X on the
-        // joystick and Y Axis = Y on the joystick.
-        js.update(y, x, z, buttons, statusFlags);
+
+        // If it's been long enough since our last USB status report,
+        // send the new report.  We throttle the report rate because
+        // it can overwhelm the PC side if we report too frequently.
+        // VP only wants to sync with the real world in 10ms intervals,
+        // so reporting more frequently only creates i/o overhead
+        // without doing anything to improve the simulation.
+        if (reportTimer.read_ms() > 15)
+        {
+            // read the accelerometer
+            int xa, ya;
+            accel.get(xa, ya);
+            
+            // confine the results to our joystick axis range
+            if (xa < -JOYMAX) xa = -JOYMAX;
+            if (xa > JOYMAX) xa = JOYMAX;
+            if (ya < -JOYMAX) ya = -JOYMAX;
+            if (ya > JOYMAX) ya = JOYMAX;
+            
+            // store the updated accelerometer coordinates
+            x = xa;
+            y = ya;
+            
+            // Send the status report.  Note that the nominal x and y axes
+            // are reversed - this makes it more intuitive to set up in VP.
+            // If we mount the Freesale card flat on the floor of the cabinet
+            // with the USB connectors facing the front of the cabinet, this
+            // arrangement of our nominal axes aligns with VP's standard
+            // setting, so that we can configure VP with X Axis = X on the
+            // joystick and Y Axis = Y on the joystick.
+            js.update(y, x, z, buttons | simButtons, statusFlags);
+            
+            // we've just started a new report interval, so reset the timer
+            reportTimer.reset();
+        }
         
         // If we're in pixel dump mode, report all pixel exposure values
         if (reportPix)
         {
+            // send the report            
+            plungerSensor.sendExposureReport(js);
+
             // we have satisfied this request
             reportPix = false;
-            
-            // send reports for all pixels
-            int idx = 0;
-            while (idx < npix)
-                js.updateExposure(idx, npix, pix);
-                
-            // The pixel dump requires many USB reports, since each report
-            // can only send a few pixel values.  An integration cycle has
-            // been running all this time, since each read starts a new
-            // cycle.  Our timing is longer than usual on this round, so
-            // the integration won't be comparable to a normal cycle.  Throw
-            // this one away by doing a read now, and throwing it away - that 
-            // will get the timing of the *next* cycle roughly back to normal.
-            ccd.read(pix, npix);
         }
         
 #ifdef DEBUG_PRINTF
@@ -1832,7 +1803,7 @@
                 ledG = (hb ? 1 : 0);
                 ledB = 0;
             }
-            else if (cfg.d.ccdEnabled && !cfg.d.plungerCal)
+            else if (cfg.d.plungerEnabled && !cfg.d.plungerCal)
             {
                 // connected, plunger calibration needed - flash yellow/green
                 hb = !hb;