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


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 Also visit my Pinscape Resources page for more about this project and other virtual pinball projects I'm working on.


  • 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.


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 potentionmeter (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 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 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 VirtuaPin kit uses the same KL25Z microcontroller that Pinscape uses, but the rest of its hardware is different and incompatible. In particular, the Pinscape firmware doesn't include support for the IR proximity sensor used in the VirtuaPin plunger kit, so you won't be able to use your plunger device with the Pinscape firmware. In addition, the VirtuaPin setup uses a different set of GPIO pins for the button inputs from the Pinscape defaults, so if you do install the Pinscape firmware, you'll have to go into the Config Tool and reassign all of the buttons to match the VirtuaPin wiring.

Fri Dec 27 20:14:23 2019 +0000
AEAT-6012, TCD1103 updates

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mjr 82:4f6209cb5c33 1 // Plunger Sensor Interface
mjr 82:4f6209cb5c33 2 //
mjr 82:4f6209cb5c33 3 // This module defines the abstract interface to the plunger sensors.
mjr 82:4f6209cb5c33 4 // We support several different physical sensor types, so we need a
mjr 82:4f6209cb5c33 5 // common interface for use in the main code.
mjr 82:4f6209cb5c33 6 //
mjr 82:4f6209cb5c33 7 // In case it's helpful in developing code for new sensor types, I've
mjr 82:4f6209cb5c33 8 // measured the maximum instantaneous speed of a plunger at .175 inches
mjr 82:4f6209cb5c33 9 // per millisecond, or 4.46 mm/ms. (I measured that with an AEDR-8300;
mjr 82:4f6209cb5c33 10 // see that code for more details.)
mjr 82:4f6209cb5c33 11 //
mjr 82:4f6209cb5c33 12
mjr 82:4f6209cb5c33 13 #ifndef PLUNGER_H
mjr 82:4f6209cb5c33 14 #define PLUNGER_H
mjr 82:4f6209cb5c33 15
mjr 87:8d35c74403af 16 #include "config.h"
mjr 87:8d35c74403af 17
mjr 82:4f6209cb5c33 18 // Plunger reading with timestamp
mjr 82:4f6209cb5c33 19 struct PlungerReading
mjr 82:4f6209cb5c33 20 {
mjr 82:4f6209cb5c33 21 // Raw sensor reading, normalied to 0x0000..0xFFFF range
mjr 82:4f6209cb5c33 22 int pos;
mjr 82:4f6209cb5c33 23
mjr 82:4f6209cb5c33 24 // Rimestamp of reading, in microseconds, relative to an arbitrary
mjr 82:4f6209cb5c33 25 // zero point. Note that a 32-bit int can only represent about 71.5
mjr 82:4f6209cb5c33 26 // minutes worth of microseconds, so this value is only meaningful
mjr 82:4f6209cb5c33 27 // to compute a delta from other recent readings. As long as two
mjr 82:4f6209cb5c33 28 // readings are within 71.5 minutes of each other, the time difference
mjr 82:4f6209cb5c33 29 // calculated from the timestamps using 32-bit math will be correct
mjr 82:4f6209cb5c33 30 // *even if a rollover occurs* between the two readings, since the
mjr 82:4f6209cb5c33 31 // calculation is done mod 2^32-1.
mjr 82:4f6209cb5c33 32 uint32_t t;
mjr 82:4f6209cb5c33 33 };
mjr 82:4f6209cb5c33 34
mjr 82:4f6209cb5c33 35 class PlungerSensor
mjr 82:4f6209cb5c33 36 {
mjr 82:4f6209cb5c33 37 public:
mjr 86:e30a1f60f783 38 PlungerSensor(int nativeScale)
mjr 86:e30a1f60f783 39 {
mjr 86:e30a1f60f783 40 // use the joystick scale as our native scale by default
mjr 86:e30a1f60f783 41 this->nativeScale = nativeScale;
mjr 86:e30a1f60f783 42
mjr 86:e30a1f60f783 43 // figure the scaling factor
mjr 86:e30a1f60f783 44 scalingFactor = (65535UL*65536UL) / nativeScale;
mjr 86:e30a1f60f783 45
mjr 86:e30a1f60f783 46 // presume no jitter filter
mjr 86:e30a1f60f783 47 jfWindow = 0;
mjr 86:e30a1f60f783 48
mjr 86:e30a1f60f783 49 // initialize the jitter filter
mjr 86:e30a1f60f783 50 jfLo = jfHi = jfLast = 0;
mjr 91:ae9be42652bf 51
mjr 91:ae9be42652bf 52 // presume normal orientation
mjr 91:ae9be42652bf 53 reverseOrientation = false;
mjr 86:e30a1f60f783 54 }
mjr 82:4f6209cb5c33 55
mjr 82:4f6209cb5c33 56 // ---------- Abstract sensor interface ----------
mjr 82:4f6209cb5c33 57
mjr 82:4f6209cb5c33 58 // Initialize the physical sensor device. This is called at startup
mjr 82:4f6209cb5c33 59 // to set up the device for first use.
mjr 82:4f6209cb5c33 60 virtual void init() { }
mjr 82:4f6209cb5c33 61
mjr 82:4f6209cb5c33 62 // Auto-zero the plunger. Relative sensor types, such as quadrature
mjr 82:4f6209cb5c33 63 // sensors, can lose sync with the absolute position over time if they
mjr 82:4f6209cb5c33 64 // ever miss any motion. We can automatically correct for this by
mjr 82:4f6209cb5c33 65 // resetting to the park position after periods of inactivity. It's
mjr 82:4f6209cb5c33 66 // usually safe to assume that the plunger is at the park position if it
mjr 82:4f6209cb5c33 67 // hasn't moved in a long time, since the spring always returns it to
mjr 82:4f6209cb5c33 68 // that position when it isn't being manipulated. The main loop monitors
mjr 82:4f6209cb5c33 69 // for motion, and calls this after a long enough time goes by without
mjr 82:4f6209cb5c33 70 // seeing any movement. Sensor types that are inherently absolute
mjr 82:4f6209cb5c33 71 // (TSL1410, potentiometers) shouldn't do anything here.
mjr 82:4f6209cb5c33 72 virtual void autoZero() { }
mjr 82:4f6209cb5c33 73
mjr 82:4f6209cb5c33 74 // Is the sensor ready to take a reading? The optical sensor requires
mjr 82:4f6209cb5c33 75 // a fairly long time (2.5ms) to transfer the data for each reading, but
mjr 82:4f6209cb5c33 76 // this is done via DMA, so we can carry on other work while the transfer
mjr 82:4f6209cb5c33 77 // takes place. This lets us poll the sensor to see if it's still busy
mjr 82:4f6209cb5c33 78 // working on the current reading's data transfer.
mjr 82:4f6209cb5c33 79 virtual bool ready() { return true; }
mjr 82:4f6209cb5c33 80
mjr 82:4f6209cb5c33 81 // Read the sensor position, if possible. Returns true on success,
mjr 82:4f6209cb5c33 82 // false if it wasn't possible to take a reading. On success, fills
mjr 86:e30a1f60f783 83 // in 'r' with the current reading and timestamp and returns true.
mjr 86:e30a1f60f783 84 // Returns false if a reading couldn't be taken.
mjr 82:4f6209cb5c33 85 //
mjr 86:e30a1f60f783 86 // r.pos is set to the normalized position reading, and r.t is set to
mjr 86:e30a1f60f783 87 // the timestamp of the reading.
mjr 82:4f6209cb5c33 88 //
mjr 86:e30a1f60f783 89 // The normalized position is the sensor reading, corrected for jitter,
mjr 86:e30a1f60f783 90 // and adjusted to the abstract 0x0000..0xFFFF range.
mjr 86:e30a1f60f783 91 //
mjr 86:e30a1f60f783 92 // The timestamp is the time the sensor reading was taken, relative to
mjr 86:e30a1f60f783 93 // an arbitrary zero point. The arbitrary zero point makes this useful
mjr 86:e30a1f60f783 94 // only for calculating the time between readings. Note that the 32-bit
mjr 86:e30a1f60f783 95 // timestamp rolls over about every 71 minutes, so it should only be
mjr 86:e30a1f60f783 96 // used for time differences between readings taken fairly close together.
mjr 86:e30a1f60f783 97 // In practice, the higher level code only uses this for a few consecutive
mjr 86:e30a1f60f783 98 // readings to calculate (nearly) instantaneous velocities, so the time
mjr 86:e30a1f60f783 99 // spans are only tens of milliseconds.
mjr 82:4f6209cb5c33 100 //
mjr 82:4f6209cb5c33 101 // Timing requirements: for best results, readings should be taken
mjr 86:e30a1f60f783 102 // in well under 5ms. The release motion of the physical plunger
mjr 86:e30a1f60f783 103 // takes from 30ms to 50ms, so we need to collect samples much faster
mjr 86:e30a1f60f783 104 // than that to avoid aliasing during the bounce.
mjr 86:e30a1f60f783 105 bool read(PlungerReading &r)
mjr 86:e30a1f60f783 106 {
mjr 101:755f44622abc 107 // fail if the hardware scan isn't ready
mjr 101:755f44622abc 108 if (!ready())
mjr 101:755f44622abc 109 return false;
mjr 101:755f44622abc 110
mjr 86:e30a1f60f783 111 // get the raw reading
mjr 86:e30a1f60f783 112 if (readRaw(r))
mjr 86:e30a1f60f783 113 {
mjr 91:ae9be42652bf 114 // adjust for orientation
mjr 91:ae9be42652bf 115 r.pos = applyOrientation(r.pos);
mjr 91:ae9be42652bf 116
mjr 86:e30a1f60f783 117 // process it through the jitter filter
mjr 87:8d35c74403af 118 r.pos = jitterFilter(r.pos);
mjr 86:e30a1f60f783 119
mjr 86:e30a1f60f783 120 // adjust to the abstract scale via the scaling factor
mjr 86:e30a1f60f783 121 r.pos = uint16_t(uint32_t((scalingFactor * r.pos) + 32768) >> 16);
mjr 86:e30a1f60f783 122
mjr 86:e30a1f60f783 123 // success
mjr 86:e30a1f60f783 124 return true;
mjr 86:e30a1f60f783 125 }
mjr 86:e30a1f60f783 126 else
mjr 86:e30a1f60f783 127 {
mjr 86:e30a1f60f783 128 // no reading is available
mjr 86:e30a1f60f783 129 return false;
mjr 86:e30a1f60f783 130 }
mjr 86:e30a1f60f783 131 }
mjr 86:e30a1f60f783 132
mjr 86:e30a1f60f783 133 // Get a raw plunger reading. This gets the raw sensor reading with
mjr 86:e30a1f60f783 134 // timestamp, without jitter filtering and without any scale adjustment.
mjr 86:e30a1f60f783 135 virtual bool readRaw(PlungerReading &r) = 0;
mjr 82:4f6209cb5c33 136
mjr 100:1ff35c07217c 137 // Restore the saved calibration data from the configuration. The main
mjr 100:1ff35c07217c 138 // loop calls this at startup to let us initialize internals from the
mjr 100:1ff35c07217c 139 // saved calibration data. This is called even if the plunger isn't
mjr 100:1ff35c07217c 140 // calibrated, which is flagged in the config.
mjr 100:1ff35c07217c 141 virtual void restoreCalibration(Config &) { }
mjr 100:1ff35c07217c 142
mjr 82:4f6209cb5c33 143 // Begin calibration. The main loop calls this when the user activates
mjr 82:4f6209cb5c33 144 // calibration mode. Sensors that work in terms of relative positions,
mjr 82:4f6209cb5c33 145 // such as quadrature-based sensors, can use this to set the reference
mjr 82:4f6209cb5c33 146 // point for the park position internally.
mjr 100:1ff35c07217c 147 virtual void beginCalibration(Config &) { }
mjr 100:1ff35c07217c 148
mjr 100:1ff35c07217c 149 // End calibration. The main loop calls this when calibration mode is
mjr 100:1ff35c07217c 150 // completed.
mjr 100:1ff35c07217c 151 virtual void endCalibration(Config &) { }
mjr 82:4f6209cb5c33 152
mjr 82:4f6209cb5c33 153 // Send a sensor status report to the host, via the joystick interface.
mjr 82:4f6209cb5c33 154 // This provides some common information for all sensor types, and also
mjr 82:4f6209cb5c33 155 // includes a full image snapshot of the current sensor pixels for
mjr 82:4f6209cb5c33 156 // imaging sensor types.
mjr 82:4f6209cb5c33 157 //
mjr 82:4f6209cb5c33 158 // The default implementation here sends the common information
mjr 82:4f6209cb5c33 159 // packet, with the pixel size set to 0.
mjr 82:4f6209cb5c33 160 //
mjr 82:4f6209cb5c33 161 // 'flags' is a combination of bit flags:
mjr 82:4f6209cb5c33 162 // 0x01 -> low-res scan (default is high res scan)
mjr 82:4f6209cb5c33 163 //
mjr 82:4f6209cb5c33 164 // Low-res scan mode means that the sensor should send a scaled-down
mjr 82:4f6209cb5c33 165 // image, at a reduced size determined by the sensor subtype. The
mjr 82:4f6209cb5c33 166 // default if this flag isn't set is to send the full image, at the
mjr 82:4f6209cb5c33 167 // sensor's native pixel size. The low-res version is a reduced size
mjr 82:4f6209cb5c33 168 // image in the normal sense of scaling down a photo image, keeping the
mjr 82:4f6209cb5c33 169 // image intact but at reduced resolution. Note that low-res mode
mjr 82:4f6209cb5c33 170 // doesn't affect the ongoing sensor operation at all. It only applies
mjr 82:4f6209cb5c33 171 // to this single pixel report. The purpose is simply to reduce the USB
mjr 82:4f6209cb5c33 172 // transmission time for the image, to allow for a faster frame rate for
mjr 82:4f6209cb5c33 173 // displaying the sensor image in real time on the PC. For a high-res
mjr 82:4f6209cb5c33 174 // sensor like the TSL1410R, sending the full pixel array by USB takes
mjr 82:4f6209cb5c33 175 // so long that the frame rate is way below regular video rates.
mjr 82:4f6209cb5c33 176 //
mjr 101:755f44622abc 177 virtual void sendStatusReport(class USBJoystick &js, uint8_t flags)
mjr 82:4f6209cb5c33 178 {
mjr 82:4f6209cb5c33 179 // read the current position
mjr 82:4f6209cb5c33 180 int pos = 0xFFFF;
mjr 82:4f6209cb5c33 181 PlungerReading r;
mjr 86:e30a1f60f783 182 if (readRaw(r))
mjr 82:4f6209cb5c33 183 {
mjr 91:ae9be42652bf 184 // adjust for reverse orientation
mjr 91:ae9be42652bf 185 r.pos = applyOrientation(r.pos);
mjr 91:ae9be42652bf 186
mjr 86:e30a1f60f783 187 // success - apply the jitter filter
mjr 86:e30a1f60f783 188 pos = jitterFilter(r.pos);
mjr 82:4f6209cb5c33 189 }
mjr 82:4f6209cb5c33 190
mjr 82:4f6209cb5c33 191 // Send the common status information, indicating 0 pixels, standard
mjr 82:4f6209cb5c33 192 // sensor orientation, and zero processing time. Non-imaging sensors
mjr 86:e30a1f60f783 193 // usually don't have any way to detect the orientation, so assume
mjr 86:e30a1f60f783 194 // normal orientation (flag 0x01). Also assume zero analysis time,
mjr 86:e30a1f60f783 195 // as most non-image sensors don't have to do anything CPU-intensive
mjr 86:e30a1f60f783 196 // with the raw readings (all they usually have to do is scale the
mjr 86:e30a1f60f783 197 // value to the abstract reporting range).
mjr 86:e30a1f60f783 198 js.sendPlungerStatus(0, pos, 0x01, getAvgScanTime(), 0);
mjr 86:e30a1f60f783 199 js.sendPlungerStatus2(nativeScale, jfLo, jfHi, r.pos, 0);
mjr 82:4f6209cb5c33 200 }
mjr 82:4f6209cb5c33 201
mjr 101:755f44622abc 202 // Set extra image integration time, in microseconds. This is only
mjr 101:755f44622abc 203 // meaningful for image-type sensors. This allows the PC client to
mjr 101:755f44622abc 204 // manually adjust the exposure time for testing and debugging
mjr 101:755f44622abc 205 // purposes.
mjr 101:755f44622abc 206 virtual void setExtraIntegrationTime(uint32_t us) { }
mjr 101:755f44622abc 207
mjr 82:4f6209cb5c33 208 // Get the average sensor scan time in microseconds
mjr 82:4f6209cb5c33 209 virtual uint32_t getAvgScanTime() = 0;
mjr 91:ae9be42652bf 210
mjr 91:ae9be42652bf 211 // Apply the orientation filter. The position is in unscaled
mjr 91:ae9be42652bf 212 // native sensor units.
mjr 91:ae9be42652bf 213 int applyOrientation(int pos)
mjr 91:ae9be42652bf 214 {
mjr 91:ae9be42652bf 215 return (reverseOrientation ? nativeScale - pos : pos);
mjr 91:ae9be42652bf 216 }
mjr 82:4f6209cb5c33 217
mjr 91:ae9be42652bf 218 // Apply the jitter filter. The position is in unscaled native
mjr 91:ae9be42652bf 219 // sensor units.
mjr 86:e30a1f60f783 220 int jitterFilter(int pos)
mjr 86:e30a1f60f783 221 {
mjr 86:e30a1f60f783 222 // Check to see where the new reading is relative to the
mjr 86:e30a1f60f783 223 // current window
mjr 86:e30a1f60f783 224 if (pos < jfLo)
mjr 86:e30a1f60f783 225 {
mjr 86:e30a1f60f783 226 // the new position is below the current window, so move
mjr 86:e30a1f60f783 227 // the window down such that the new point is at the bottom
mjr 86:e30a1f60f783 228 // of the window
mjr 86:e30a1f60f783 229 jfLo = pos;
mjr 86:e30a1f60f783 230 jfHi = pos + jfWindow;
mjr 87:8d35c74403af 231
mjr 87:8d35c74403af 232 // figure the new position as the centerpoint of the new window
mjr 87:8d35c74403af 233 jfLast = pos = (jfHi + jfLo)/2;
mjr 86:e30a1f60f783 234 return pos;
mjr 86:e30a1f60f783 235 }
mjr 86:e30a1f60f783 236 else if (pos > jfHi)
mjr 86:e30a1f60f783 237 {
mjr 86:e30a1f60f783 238 // the new position is above the current window, so move
mjr 86:e30a1f60f783 239 // the window up such that the new point is at the top of
mjr 86:e30a1f60f783 240 // the window
mjr 86:e30a1f60f783 241 jfHi = pos;
mjr 86:e30a1f60f783 242 jfLo = pos - jfWindow;
mjr 87:8d35c74403af 243
mjr 87:8d35c74403af 244 // figure the new position as the centerpoint of the new window
mjr 87:8d35c74403af 245 jfLast = pos = (jfHi + jfLo)/2;
mjr 86:e30a1f60f783 246 return pos;
mjr 86:e30a1f60f783 247 }
mjr 86:e30a1f60f783 248 else
mjr 86:e30a1f60f783 249 {
mjr 86:e30a1f60f783 250 // the new position is inside the current window, so repeat
mjr 86:e30a1f60f783 251 // the last reading
mjr 86:e30a1f60f783 252 return jfLast;
mjr 86:e30a1f60f783 253 }
mjr 86:e30a1f60f783 254 }
mjr 86:e30a1f60f783 255
mjr 87:8d35c74403af 256 // Process a configuration variable change. 'varno' is the
mjr 87:8d35c74403af 257 // USB protocol variable number being updated; 'cfg' is the
mjr 87:8d35c74403af 258 // updated configuration.
mjr 87:8d35c74403af 259 virtual void onConfigChange(int varno, Config &cfg)
mjr 87:8d35c74403af 260 {
mjr 87:8d35c74403af 261 switch (varno)
mjr 87:8d35c74403af 262 {
mjr 87:8d35c74403af 263 case 19:
mjr 91:ae9be42652bf 264 // Plunger filters - jitter window and reverse orientation.
mjr 87:8d35c74403af 265 setJitterWindow(cfg.plunger.jitterWindow);
mjr 91:ae9be42652bf 266 setReverseOrientation((cfg.plunger.reverseOrientation & 0x01) != 0);
mjr 87:8d35c74403af 267 break;
mjr 87:8d35c74403af 268 }
mjr 87:8d35c74403af 269 }
mjr 87:8d35c74403af 270
mjr 86:e30a1f60f783 271 // Set the jitter filter window size. This is specified in native
mjr 86:e30a1f60f783 272 // sensor units.
mjr 86:e30a1f60f783 273 void setJitterWindow(int w)
mjr 86:e30a1f60f783 274 {
mjr 86:e30a1f60f783 275 // set the new window size
mjr 86:e30a1f60f783 276 jfWindow = w;
mjr 86:e30a1f60f783 277
mjr 86:e30a1f60f783 278 // reset the running window
mjr 86:e30a1f60f783 279 jfHi = jfLo = jfLast;
mjr 86:e30a1f60f783 280 }
mjr 91:ae9be42652bf 281
mjr 91:ae9be42652bf 282 // Set reverse orientation
mjr 91:ae9be42652bf 283 void setReverseOrientation(bool f) { reverseOrientation = f; }
mjr 86:e30a1f60f783 284
mjr 82:4f6209cb5c33 285 protected:
mjr 86:e30a1f60f783 286 // Native scale of the device. This is the scale used for the position
mjr 86:e30a1f60f783 287 // reading in status reports. This lets us report the position in the
mjr 86:e30a1f60f783 288 // same units the sensor itself uses, to avoid any rounding error
mjr 86:e30a1f60f783 289 // converting to an abstract scale.
mjr 86:e30a1f60f783 290 //
mjr 91:ae9be42652bf 291 // The nativeScale value is the number of units in the range of raw
mjr 91:ae9be42652bf 292 // sensor readings returned from readRaw(). Raw readings thus have a
mjr 91:ae9be42652bf 293 // valid range of 0 to nativeScale-1.
mjr 91:ae9be42652bf 294 //
mjr 86:e30a1f60f783 295 // Image edge detection sensors use the pixel size of the image, since
mjr 86:e30a1f60f783 296 // the position is determined by the pixel position of the shadow in
mjr 86:e30a1f60f783 297 // the image. Quadrature sensors and other sensors that report the
mjr 86:e30a1f60f783 298 // distance in terms of physical distance units should use the number
mjr 86:e30a1f60f783 299 // of quanta in the approximate total plunger travel distance of 3".
mjr 86:e30a1f60f783 300 // For example, the VL6180X uses millimeter quanta, so can report
mjr 86:e30a1f60f783 301 // about 77 quanta over 3"; a quadrature sensor that reports at 1/300"
mjr 86:e30a1f60f783 302 // intervals has about 900 quanta over 3". Absolute encoders (e.g.,
mjr 86:e30a1f60f783 303 // bar code sensors) should use the bar code range.
mjr 86:e30a1f60f783 304 //
mjr 86:e30a1f60f783 305 // Sensors that are inherently analog (e.g., potentiometers, analog
mjr 86:e30a1f60f783 306 // distance sensors) can quantize on any arbitrary scale. In most cases,
mjr 86:e30a1f60f783 307 // it's best to use the same 0..65535 scale used for the regular plunger
mjr 86:e30a1f60f783 308 // reports.
mjr 86:e30a1f60f783 309 uint16_t nativeScale;
mjr 86:e30a1f60f783 310
mjr 86:e30a1f60f783 311 // Scaling factor to convert native readings to abstract units on the
mjr 86:e30a1f60f783 312 // 0x0000..0xFFFF scale used in the higher level sensor-independent
mjr 86:e30a1f60f783 313 // code. Multiply a raw sensor position reading by this value to
mjr 86:e30a1f60f783 314 // get the equivalent value on the abstract scale. This is expressed
mjr 86:e30a1f60f783 315 // as a fixed-point real number with a scale of 65536: calculate it as
mjr 86:e30a1f60f783 316 //
mjr 86:e30a1f60f783 317 // (65535U*65536U) / (nativeScale - 1);
mjr 86:e30a1f60f783 318 uint32_t scalingFactor;
mjr 86:e30a1f60f783 319
mjr 86:e30a1f60f783 320 // Jitter filtering
mjr 86:e30a1f60f783 321 int jfWindow; // window size, in native sensor units
mjr 86:e30a1f60f783 322 int jfLo, jfHi; // bounds of current window
mjr 86:e30a1f60f783 323 int jfLast; // last filtered reading
mjr 91:ae9be42652bf 324
mjr 91:ae9be42652bf 325 // Reverse the raw reading orientation. If set, raw readings will be
mjr 91:ae9be42652bf 326 // switched to the opposite orientation. This allows flipping the sensor
mjr 91:ae9be42652bf 327 // orientation virtually to correct for installing the physical device
mjr 91:ae9be42652bf 328 // backwards.
mjr 91:ae9be42652bf 329 bool reverseOrientation;
mjr 82:4f6209cb5c33 330 };
mjr 82:4f6209cb5c33 331
mjr 87:8d35c74403af 332
mjr 87:8d35c74403af 333 // --------------------------------------------------------------------------
mjr 87:8d35c74403af 334 //
mjr 101:755f44622abc 335 // Generic image sensor interface for image-based plungers.
mjr 101:755f44622abc 336 //
mjr 101:755f44622abc 337 // This interface is designed to allow the underlying sensor code to work
mjr 101:755f44622abc 338 // asynchronously to transfer pixels from the sensor into memory using
mjr 101:755f44622abc 339 // multiple buffers arranged in a circular list. We have a "ready" state,
mjr 101:755f44622abc 340 // which lets the sensor tell us when a buffer is available, and we have
mjr 101:755f44622abc 341 // the notion of "ownership" of the buffer. When the client is done with
mjr 101:755f44622abc 342 // a frame, it must realease the frame back to the sensor so that the sensor
mjr 101:755f44622abc 343 // can use it for a subsequent frame transfer.
mjr 87:8d35c74403af 344 //
mjr 87:8d35c74403af 345 class PlungerSensorImageInterface
mjr 87:8d35c74403af 346 {
mjr 87:8d35c74403af 347 public:
mjr 87:8d35c74403af 348 PlungerSensorImageInterface(int npix)
mjr 87:8d35c74403af 349 {
mjr 87:8d35c74403af 350 native_npix = npix;
mjr 87:8d35c74403af 351 }
mjr 87:8d35c74403af 352
mjr 87:8d35c74403af 353 // initialize the sensor
mjr 87:8d35c74403af 354 virtual void init() = 0;
mjr 87:8d35c74403af 355
mjr 87:8d35c74403af 356 // is the sensor ready?
mjr 87:8d35c74403af 357 virtual bool ready() = 0;
mjr 87:8d35c74403af 358
mjr 101:755f44622abc 359 // Read the image. This retrieves a pointer to the current frame
mjr 101:755f44622abc 360 // buffer, which is in memory space managed by the sensor. This
mjr 101:755f44622abc 361 // MUST only be called when ready() returns true. The buffer is
mjr 101:755f44622abc 362 // locked for the client's use until the client calls releasePix().
mjr 101:755f44622abc 363 // The client MUST call releasePix() when done with the buffer, so
mjr 101:755f44622abc 364 // that the sensor can reuse it for another frame.
mjr 101:755f44622abc 365 virtual void readPix(uint8_t* &pix, uint32_t &t) = 0;
mjr 87:8d35c74403af 366
mjr 101:755f44622abc 367 // Release the current frame buffer back to the sensor.
mjr 101:755f44622abc 368 virtual void releasePix() = 0;
mjr 87:8d35c74403af 369
mjr 87:8d35c74403af 370 // get the average sensor pixel scan time (the time it takes on average
mjr 87:8d35c74403af 371 // to read one image frame from the sensor)
mjr 87:8d35c74403af 372 virtual uint32_t getAvgScanTime() = 0;
mjr 87:8d35c74403af 373
mjr 101:755f44622abc 374 // Set the minimum integration time (microseconds)
mjr 101:755f44622abc 375 virtual void setMinIntTime(uint32_t us) = 0;
mjr 101:755f44622abc 376
mjr 87:8d35c74403af 377 protected:
mjr 87:8d35c74403af 378 // number of pixels on sensor
mjr 87:8d35c74403af 379 int native_npix;
mjr 87:8d35c74403af 380 };
mjr 87:8d35c74403af 381
mjr 87:8d35c74403af 382
mjr 87:8d35c74403af 383 // ----------------------------------------------------------------------------
mjr 87:8d35c74403af 384 //
mjr 87:8d35c74403af 385 // Plunger base class for image-based sensors
mjr 87:8d35c74403af 386 //
mjr 104:6e06e0f4b476 387 template<typename ProcessResult>
mjr 87:8d35c74403af 388 class PlungerSensorImage: public PlungerSensor
mjr 87:8d35c74403af 389 {
mjr 87:8d35c74403af 390 public:
mjr 104:6e06e0f4b476 391 PlungerSensorImage(PlungerSensorImageInterface &sensor,
mjr 104:6e06e0f4b476 392 int npix, int nativeScale, bool negativeImage = false) :
mjr 104:6e06e0f4b476 393 PlungerSensor(nativeScale),
mjr 104:6e06e0f4b476 394 sensor(sensor),
mjr 104:6e06e0f4b476 395 native_npix(npix),
mjr 104:6e06e0f4b476 396 negativeImage(negativeImage),
mjr 104:6e06e0f4b476 397 axcTime(0),
mjr 104:6e06e0f4b476 398 extraIntTime(0)
mjr 87:8d35c74403af 399 {
mjr 87:8d35c74403af 400 }
mjr 87:8d35c74403af 401
mjr 87:8d35c74403af 402 // initialize the sensor
mjr 87:8d35c74403af 403 virtual void init() { sensor.init(); }
mjr 87:8d35c74403af 404
mjr 87:8d35c74403af 405 // is the sensor ready?
mjr 87:8d35c74403af 406 virtual bool ready() { return sensor.ready(); }
mjr 87:8d35c74403af 407
mjr 87:8d35c74403af 408 // get the pixel transfer time
mjr 87:8d35c74403af 409 virtual uint32_t getAvgScanTime() { return sensor.getAvgScanTime(); }
mjr 87:8d35c74403af 410
mjr 101:755f44622abc 411 // set extra integration time
mjr 101:755f44622abc 412 virtual void setExtraIntegrationTime(uint32_t us) { extraIntTime = us; }
mjr 101:755f44622abc 413
mjr 87:8d35c74403af 414 // read the plunger position
mjr 87:8d35c74403af 415 virtual bool readRaw(PlungerReading &r)
mjr 87:8d35c74403af 416 {
mjr 87:8d35c74403af 417 // read pixels from the sensor
mjr 87:8d35c74403af 418 uint8_t *pix;
mjr 87:8d35c74403af 419 uint32_t tpix;
mjr 101:755f44622abc 420 sensor.readPix(pix, tpix);
mjr 87:8d35c74403af 421
mjr 87:8d35c74403af 422 // process the pixels
mjr 87:8d35c74403af 423 int pixpos;
mjr 87:8d35c74403af 424 ProcessResult res;
mjr 101:755f44622abc 425 bool ok = process(pix, native_npix, pixpos, res);
mjr 101:755f44622abc 426
mjr 101:755f44622abc 427 // release the buffer back to the sensor
mjr 101:755f44622abc 428 sensor.releasePix();
mjr 101:755f44622abc 429
mjr 101:755f44622abc 430 // adjust the exposure time
mjr 101:755f44622abc 431 sensor.setMinIntTime(axcTime + extraIntTime);
mjr 101:755f44622abc 432
mjr 101:755f44622abc 433 // if we successfully processed the frame, read the position
mjr 101:755f44622abc 434 if (ok)
mjr 87:8d35c74403af 435 {
mjr 87:8d35c74403af 436 r.pos = pixpos;
mjr 87:8d35c74403af 437 r.t = tpix;
mjr 87:8d35c74403af 438 }
mjr 101:755f44622abc 439
mjr 101:755f44622abc 440 // return the result
mjr 101:755f44622abc 441 return ok;
mjr 87:8d35c74403af 442 }
mjr 87:8d35c74403af 443
mjr 87:8d35c74403af 444 // Send a status report to the joystick interface.
mjr 87:8d35c74403af 445 // See plunger.h for details on the arguments.
mjr 101:755f44622abc 446 virtual void sendStatusReport(USBJoystick &js, uint8_t flags)
mjr 87:8d35c74403af 447 {
mjr 104:6e06e0f4b476 448 // start a timer to measure the processing time
mjr 104:6e06e0f4b476 449 Timer pt;
mjr 104:6e06e0f4b476 450 pt.start();
mjr 104:6e06e0f4b476 451
mjr 87:8d35c74403af 452 // get pixels
mjr 87:8d35c74403af 453 uint8_t *pix;
mjr 87:8d35c74403af 454 uint32_t t;
mjr 101:755f44622abc 455 sensor.readPix(pix, t);
mjr 87:8d35c74403af 456
mjr 87:8d35c74403af 457 // process the pixels and read the position
mjr 87:8d35c74403af 458 int pos, rawPos;
mjr 87:8d35c74403af 459 int n = native_npix;
mjr 87:8d35c74403af 460 ProcessResult res;
mjr 87:8d35c74403af 461 if (process(pix, n, rawPos, res))
mjr 87:8d35c74403af 462 {
mjr 87:8d35c74403af 463 // success - apply the jitter filter
mjr 87:8d35c74403af 464 pos = jitterFilter(rawPos);
mjr 87:8d35c74403af 465 }
mjr 87:8d35c74403af 466 else
mjr 87:8d35c74403af 467 {
mjr 87:8d35c74403af 468 // report 0xFFFF to indicate that the position wasn't read
mjr 87:8d35c74403af 469 pos = 0xFFFF;
mjr 87:8d35c74403af 470 rawPos = 0xFFFF;
mjr 87:8d35c74403af 471 }
mjr 87:8d35c74403af 472
mjr 101:755f44622abc 473 // adjust the exposure time
mjr 101:755f44622abc 474 sensor.setMinIntTime(axcTime + extraIntTime);
mjr 101:755f44622abc 475
mjr 87:8d35c74403af 476 // note the processing time
mjr 87:8d35c74403af 477 uint32_t processTime = pt.read_us();
mjr 87:8d35c74403af 478
mjr 87:8d35c74403af 479 // If a low-res scan is desired, reduce to a subset of pixels. Ignore
mjr 87:8d35c74403af 480 // this for smaller sensors (below 512 pixels)
mjr 87:8d35c74403af 481 if ((flags & 0x01) && n >= 512)
mjr 87:8d35c74403af 482 {
mjr 87:8d35c74403af 483 // figure how many sensor pixels we combine into each low-res pixel
mjr 87:8d35c74403af 484 const int group = 8;
mjr 87:8d35c74403af 485 int lowResPix = n / group;
mjr 87:8d35c74403af 486
mjr 87:8d35c74403af 487 // combine the pixels
mjr 87:8d35c74403af 488 int src, dst;
mjr 87:8d35c74403af 489 for (src = dst = 0 ; dst < lowResPix ; ++dst)
mjr 87:8d35c74403af 490 {
mjr 87:8d35c74403af 491 // average this block of pixels
mjr 87:8d35c74403af 492 int a = 0;
mjr 87:8d35c74403af 493 for (int j = 0 ; j < group ; ++j)
mjr 87:8d35c74403af 494 a += pix[src++];
mjr 87:8d35c74403af 495
mjr 87:8d35c74403af 496 // we have the sum, so get the average
mjr 87:8d35c74403af 497 a /= group;
mjr 87:8d35c74403af 498
mjr 87:8d35c74403af 499 // store the down-res'd pixel in the array
mjr 87:8d35c74403af 500 pix[dst] = uint8_t(a);
mjr 87:8d35c74403af 501 }
mjr 87:8d35c74403af 502
mjr 87:8d35c74403af 503 // update the pixel count to the reduced array size
mjr 87:8d35c74403af 504 n = lowResPix;
mjr 87:8d35c74403af 505 }
mjr 87:8d35c74403af 506
mjr 87:8d35c74403af 507 // figure the report flags
mjr 87:8d35c74403af 508 int jsflags = 0;
mjr 87:8d35c74403af 509
mjr 87:8d35c74403af 510 // add flags for the detected orientation: 0x01 for normal orientation,
mjr 87:8d35c74403af 511 // 0x02 for reversed orientation; no flags if orientation is unknown
mjr 87:8d35c74403af 512 int dir = getOrientation();
mjr 87:8d35c74403af 513 if (dir == 1)
mjr 87:8d35c74403af 514 jsflags |= 0x01;
mjr 87:8d35c74403af 515 else if (dir == -1)
mjr 87:8d35c74403af 516 jsflags |= 0x02;
mjr 87:8d35c74403af 517
mjr 87:8d35c74403af 518 // send the sensor status report headers
mjr 87:8d35c74403af 519 js.sendPlungerStatus(n, pos, jsflags, sensor.getAvgScanTime(), processTime);
mjr 87:8d35c74403af 520 js.sendPlungerStatus2(nativeScale, jfLo, jfHi, rawPos, axcTime);
mjr 104:6e06e0f4b476 521
mjr 87:8d35c74403af 522 // send any extra status headers for subclasses
mjr 87:8d35c74403af 523 extraStatusHeaders(js, res);
mjr 87:8d35c74403af 524
mjr 87:8d35c74403af 525 // If we're not in calibration mode, send the pixels
mjr 87:8d35c74403af 526 extern bool plungerCalMode;
mjr 87:8d35c74403af 527 if (!plungerCalMode)
mjr 87:8d35c74403af 528 {
mjr 104:6e06e0f4b476 529 // If the sensor uses a negative image format (brighter pixels are
mjr 104:6e06e0f4b476 530 // represented by lower numbers in the pixel array), invert the scale
mjr 104:6e06e0f4b476 531 // back to a normal photo-positive scale, so that the client doesn't
mjr 104:6e06e0f4b476 532 // have to know these details.
mjr 104:6e06e0f4b476 533 if (negativeImage)
mjr 104:6e06e0f4b476 534 {
mjr 104:6e06e0f4b476 535 // Invert the photo-negative 255..0 scale to a normal,
mjr 104:6e06e0f4b476 536 // photo-positive 0..255 scale. This is just a matter of
mjr 104:6e06e0f4b476 537 // calculating pos_pixel = 255 - neg_pixel for each pixel.
mjr 104:6e06e0f4b476 538 //
mjr 104:6e06e0f4b476 539 // There's a shortcut we can use here to make this loop go a
mjr 104:6e06e0f4b476 540 // lot faster than the naive approach. Note that 255 decimal
mjr 104:6e06e0f4b476 541 // is 1111111 binary. Subtracting any other binary number
mjr 104:6e06e0f4b476 542 // (in the range 0..255) from 255 will have the effect of
mjr 104:6e06e0f4b476 543 // simply inverting all of the bits in the original number.
mjr 104:6e06e0f4b476 544 // So 255 - X == ~X for any X in 0..255. That might not sound
mjr 104:6e06e0f4b476 545 // like a big deal, but it's actually pretty great, because it
mjr 104:6e06e0f4b476 546 // means that we only have to operate on the bits individually,
mjr 104:6e06e0f4b476 547 // rather than doing arithmetic on the bytes. And if we can
mjr 104:6e06e0f4b476 548 // operate on the bits individually, we can operate on them
mjr 104:6e06e0f4b476 549 // in the largest groups we can with the processor's native
mjr 104:6e06e0f4b476 550 // instruction set, which in the case of ARM is 32-bit DWORDs.
mjr 104:6e06e0f4b476 551 // In other words, we can iterate over the array as a DWORD
mjr 104:6e06e0f4b476 552 // array rather than a BYTE array, which cuts loop iterations
mjr 104:6e06e0f4b476 553 // by a factor of 4.
mjr 104:6e06e0f4b476 554 //
mjr 104:6e06e0f4b476 555 // One other small optimization we can apply is to notice that
mjr 104:6e06e0f4b476 556 // ~X == X ^ ~0, and X ^= ~0 happens to optimize to a single
mjr 104:6e06e0f4b476 557 // ARM instruction. So we can make the ARM C++ compiler
mjr 104:6e06e0f4b476 558 // translate this loop into three assembly instructions (XOR
mjr 104:6e06e0f4b476 559 // with immediate data and auto-increment pointer, decrement
mjr 104:6e06e0f4b476 560 // counter, jump if not zero), which is as fast as we could
mjr 104:6e06e0f4b476 561 // write it in assembly by hand. (This really works in
mjr 104:6e06e0f4b476 562 // practice, too: I clocked this loop at 60us for the
mjr 104:6e06e0f4b476 563 // 1500-pixel TCD1103 array.)
mjr 104:6e06e0f4b476 564 //
mjr 104:6e06e0f4b476 565 uint32_t *pix32 = reinterpret_cast<uint32_t*>(pix);
mjr 104:6e06e0f4b476 566 for (int i = n/4; i != 0; --i)
mjr 104:6e06e0f4b476 567 *pix32++ ^= 0xFFFFFFFF;
mjr 104:6e06e0f4b476 568
mjr 104:6e06e0f4b476 569 // Note! If we ever needed to do this with a sensor where
mjr 104:6e06e0f4b476 570 // the pixel count isn't a multiple of four, we'd have to
mjr 104:6e06e0f4b476 571 // add some code here to deal with the stragglers (the one,
mjr 104:6e06e0f4b476 572 // two, or three extra pixels after the last group of four).
mjr 104:6e06e0f4b476 573 // That's not an issue with any currently supported sensor,
mjr 104:6e06e0f4b476 574 // nor is it likely to be in the future (because any large
mjr 104:6e06e0f4b476 575 // pixel array will be built out of repeated submodules,
mjr 104:6e06e0f4b476 576 // which inherently makes power-of-two bases likely, and
mjr 104:6e06e0f4b476 577 // because engineers tend to have a bias for round numbers
mjr 104:6e06e0f4b476 578 // even when they have to choose arbitrarily). So I'm not
mjr 104:6e06e0f4b476 579 // going to test for this possibility, to save the run-time
mjr 104:6e06e0f4b476 580 // cost. And the worst that happens is we see a couple of
mjr 104:6e06e0f4b476 581 // glitchy-looking pixels at the end of the array in the
mjr 104:6e06e0f4b476 582 // visualizer on the client. But just in case, here's the
mjr 104:6e06e0f4b476 583 // code that would be needed...
mjr 104:6e06e0f4b476 584 //
mjr 104:6e06e0f4b476 585 // int extraPix = n & 3; // remainder of n/4
mjr 104:6e06e0f4b476 586 // for (int i = 0; i < extraPix; ++i)
mjr 104:6e06e0f4b476 587 // reinterpret_cast<uint8_t*>(pix32)[i] ^= 0xFF;
mjr 104:6e06e0f4b476 588 }
mjr 104:6e06e0f4b476 589
mjr 87:8d35c74403af 590 // send the pixels in report-sized chunks until we get them all
mjr 87:8d35c74403af 591 int idx = 0;
mjr 87:8d35c74403af 592 while (idx < n)
mjr 87:8d35c74403af 593 js.sendPlungerPix(idx, n, pix);
mjr 87:8d35c74403af 594 }
mjr 87:8d35c74403af 595
mjr 101:755f44622abc 596 // release the pixel buffer
mjr 101:755f44622abc 597 sensor.releasePix();
mjr 87:8d35c74403af 598 }
mjr 87:8d35c74403af 599
mjr 87:8d35c74403af 600 protected:
mjr 87:8d35c74403af 601 // process an image to read the plunger position
mjr 100:1ff35c07217c 602 virtual bool process(const uint8_t *pix, int npix, int &rawPos, ProcessResult &res) = 0;
mjr 87:8d35c74403af 603
mjr 87:8d35c74403af 604 // send extra status headers, following the standard headers (types 0 and 1)
mjr 87:8d35c74403af 605 virtual void extraStatusHeaders(USBJoystick &js, ProcessResult &res) { }
mjr 87:8d35c74403af 606
mjr 87:8d35c74403af 607 // get the detected orientation
mjr 87:8d35c74403af 608 virtual int getOrientation() const { return 0; }
mjr 87:8d35c74403af 609
mjr 87:8d35c74403af 610 // underlying hardware sensor interface
mjr 87:8d35c74403af 611 PlungerSensorImageInterface &sensor;
mjr 104:6e06e0f4b476 612
mjr 87:8d35c74403af 613 // number of pixels
mjr 87:8d35c74403af 614 int native_npix;
mjr 87:8d35c74403af 615
mjr 104:6e06e0f4b476 616 // Does the sensor report a "negative" image? This is like a photo
mjr 104:6e06e0f4b476 617 // negative, where brighter pixels are represented by lower numbers in
mjr 104:6e06e0f4b476 618 // the pixel array.
mjr 104:6e06e0f4b476 619 bool negativeImage;
mjr 104:6e06e0f4b476 620
mjr 101:755f44622abc 621 // Auto-exposure time. This is for use by process() in the subclass.
mjr 101:755f44622abc 622 // On each frame processing iteration, it can adjust this to optimize
mjr 101:755f44622abc 623 // the image quality.
mjr 87:8d35c74403af 624 uint32_t axcTime;
mjr 101:755f44622abc 625
mjr 101:755f44622abc 626 // Extra exposure time. This is for use by the PC side, mostly for
mjr 101:755f44622abc 627 // debugging use to allow the PC user to manually adjust the exposure
mjr 101:755f44622abc 628 // when inspecting captured frames.
mjr 101:755f44622abc 629 uint32_t extraIntTime;
mjr 87:8d35c74403af 630 };
mjr 87:8d35c74403af 631
mjr 87:8d35c74403af 632
mjr 82:4f6209cb5c33 633 #endif /* PLUNGER_H */