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 mechanical plunger, button inputs, and feedback device control.

In case you haven't heard of the idea 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 show the backglass artwork. Some cabs also include a third monitor to simulate the DMD (Dot Matrix Display) used for scoring on 1990s machines, or even an original plasma DMD. A computer (usually a Windows PC) 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 trim hardware.

It's possible to buy a pre-built virtual pinball machine, but it also makes a great 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.)

Committer:
mjr
Date:
Fri Apr 21 18:50:37 2017 +0000
Revision:
86:e30a1f60f783
Parent:
82:4f6209cb5c33
Child:
87:8d35c74403af
Capture a bunch of alternative bar code decoder tests, mostly unsuccessful

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mjr 82:4f6209cb5c33 1 // Plunger sensor type for bar-code based absolute position encoders.
mjr 82:4f6209cb5c33 2 // This type of sensor uses an optical sensor that moves with the plunger
mjr 82:4f6209cb5c33 3 // along a guide rail with printed bar codes along its length that encode
mjr 82:4f6209cb5c33 4 // the absolute position at each point. We figure the plunger position
mjr 82:4f6209cb5c33 5 // by reading the bar code and decoding it into a position figure.
mjr 82:4f6209cb5c33 6 //
mjr 82:4f6209cb5c33 7 // The bar code has to be encoded in a specific format that we recognize.
mjr 82:4f6209cb5c33 8 // We use a 10-bit reflected Gray code, optically encoded using a Manchester-
mjr 82:4f6209cb5c33 9 // type of coding. Each bit is represented as a fixed-width area on the
mjr 82:4f6209cb5c33 10 // bar, half white and half black. The bit value is encoded in the order
mjr 82:4f6209cb5c33 11 // of the colors: Black/White is '0', and White/Black is '1'.
mjr 82:4f6209cb5c33 12 //
mjr 86:e30a1f60f783 13 // Gray codes are ideal for this type of application. Gray codes are
mjr 86:e30a1f60f783 14 // defined such that each code point differs in exactly one bit from each
mjr 86:e30a1f60f783 15 // adjacent code point. This provides natural error correction when used
mjr 86:e30a1f60f783 16 // as a position scale, since any single-bit error will yield a code point
mjr 86:e30a1f60f783 17 // reading that's only one spot off from the true position. So a bit read
mjr 86:e30a1f60f783 18 // error acts like a reduction in precision. Likewise, any time the sensor
mjr 86:e30a1f60f783 19 // is halfway between two code points, only one bit will be ambiguous, so
mjr 86:e30a1f60f783 20 // the reading will come out as one of points on either side of the true
mjr 86:e30a1f60f783 21 // position. Finally, motion blur will have the same effect, of creating
mjr 86:e30a1f60f783 22 // ambiguity in the least significant bits, and thus giving us a reading
mjr 86:e30a1f60f783 23 // that's correct to as many bits as we can read with teh blur.
mjr 82:4f6209cb5c33 24 //
mjr 82:4f6209cb5c33 25 // We use the Manchester-type optical coding because it has good properties
mjr 86:e30a1f60f783 26 // for low-contrast images, and doesn't require uniform lighting. Each bit's
mjr 86:e30a1f60f783 27 // pixel span contains equal numbers of light and dark pixels, so each bit
mjr 86:e30a1f60f783 28 // provides its own local level reference. This means we don't care about
mjr 86:e30a1f60f783 29 // lighting uniformity over the whole image, because we don't need a global
mjr 86:e30a1f60f783 30 // notion of light and dark, just a local one over a single bit at a time.
mjr 82:4f6209cb5c33 31 //
mjr 82:4f6209cb5c33 32
mjr 82:4f6209cb5c33 33 #ifndef _BARCODESENSOR_H_
mjr 82:4f6209cb5c33 34 #define _BARCODESENSOR_H_
mjr 82:4f6209cb5c33 35
mjr 82:4f6209cb5c33 36 #include "plunger.h"
mjr 82:4f6209cb5c33 37 #include "tsl14xxSensor.h"
mjr 82:4f6209cb5c33 38
mjr 82:4f6209cb5c33 39 // Base class for bar-code sensors
mjr 86:e30a1f60f783 40 //
mjr 86:e30a1f60f783 41 // This is a template class with template parameters for the bar
mjr 86:e30a1f60f783 42 // code pixel structure. The bar code layout is fixed for a given
mjr 86:e30a1f60f783 43 // sensor type. We can assume fixed pixel sizes because we don't
mjr 86:e30a1f60f783 44 // have to process arbitrary images. We only have to read scales
mjr 86:e30a1f60f783 45 // specially prepared for this application, so we can count on them
mjr 86:e30a1f60f783 46 // being printed at an exact size relative to the sensor pixels.
mjr 86:e30a1f60f783 47 //
mjr 86:e30a1f60f783 48 // nBits = Number of bits in the code
mjr 86:e30a1f60f783 49 //
mjr 86:e30a1f60f783 50 // leftBarWidth = Width in pixels of delimiting left bar. The code is
mjr 86:e30a1f60f783 51 // delimited by a black bar on the "left" end, nearest pixel 0. This
mjr 86:e30a1f60f783 52 // gives the pixel width of the bar.
mjr 86:e30a1f60f783 53 //
mjr 86:e30a1f60f783 54 // leftBarMaxOfs = Maximum offset of the delimiting bar from the left
mjr 86:e30a1f60f783 55 // edge of the sensor (pixel 0), in pixels
mjr 86:e30a1f60f783 56 //
mjr 86:e30a1f60f783 57 // bitWidth = Width of each bit in pixels. This is the width of the
mjr 86:e30a1f60f783 58 // full bit, including both "half bits" - it's the full white/black or
mjr 86:e30a1f60f783 59 // black/white pattern area.
mjr 86:e30a1f60f783 60
mjr 86:e30a1f60f783 61 template <int nBits, int leftBarWidth, int leftBarMaxOfs, int bitWidth>
mjr 82:4f6209cb5c33 62 class PlungerSensorBarCode
mjr 82:4f6209cb5c33 63 {
mjr 82:4f6209cb5c33 64 public:
mjr 86:e30a1f60f783 65 // process the image
mjr 82:4f6209cb5c33 66 bool process(const uint8_t *pix, int npix, int &pos)
mjr 82:4f6209cb5c33 67 {
mjr 86:e30a1f60f783 68 #if 0 // $$$
mjr 86:e30a1f60f783 69
mjr 86:e30a1f60f783 70 // scan from the left edge until we find the fixed '0' start bit
mjr 86:e30a1f60f783 71 for (int i = 0 ; i < leftBarMaxOfs ; ++i, ++pix)
mjr 86:e30a1f60f783 72 {
mjr 86:e30a1f60f783 73 // check for the '0' bit
mjr 86:e30a1f60f783 74 if (readBit8(pix) == 0)
mjr 86:e30a1f60f783 75 {
mjr 86:e30a1f60f783 76 // got it - skip the start bit
mjr 86:e30a1f60f783 77 pix += bitWidth;
mjr 86:e30a1f60f783 78
mjr 86:e30a1f60f783 79 // read the gray code bits
mjr 86:e30a1f60f783 80 int gray = 0;
mjr 86:e30a1f60f783 81 for (int j = 0 ; j < nBits ; ++j, pix += bitWidth)
mjr 86:e30a1f60f783 82 {
mjr 86:e30a1f60f783 83 // read the bit; return failure if we can't decode a bit
mjr 86:e30a1f60f783 84 int bit = readBit8(pix);
mjr 86:e30a1f60f783 85 if (bit < 0)
mjr 86:e30a1f60f783 86 return false;
mjr 86:e30a1f60f783 87
mjr 86:e30a1f60f783 88 // shift it into the code
mjr 86:e30a1f60f783 89 gray = (gray << 1) | bit;
mjr 86:e30a1f60f783 90 }
mjr 86:e30a1f60f783 91 }
mjr 86:e30a1f60f783 92
mjr 86:e30a1f60f783 93 // convert the gray code to binary
mjr 86:e30a1f60f783 94 int bin = grayToBin(gray);
mjr 86:e30a1f60f783 95
mjr 86:e30a1f60f783 96 // compute the parity of the binary value
mjr 86:e30a1f60f783 97 int parity = 0;
mjr 86:e30a1f60f783 98 for (int j = 0 ; j < nBits ; ++j)
mjr 86:e30a1f60f783 99 parity ^= bin >> j;
mjr 86:e30a1f60f783 100
mjr 86:e30a1f60f783 101 // figure the bit required for odd parity
mjr 86:e30a1f60f783 102 int odd = (parity & 0x01) ^ 0x01;
mjr 86:e30a1f60f783 103
mjr 86:e30a1f60f783 104 // read the check bit
mjr 86:e30a1f60f783 105 int bit = readBit8(pix);
mjr 86:e30a1f60f783 106 if (pix < 0)
mjr 86:e30a1f60f783 107 return false;
mjr 86:e30a1f60f783 108
mjr 86:e30a1f60f783 109 // check that it matches the expected parity
mjr 86:e30a1f60f783 110 if (bit != odd)
mjr 86:e30a1f60f783 111 return false;
mjr 86:e30a1f60f783 112
mjr 86:e30a1f60f783 113 // success
mjr 86:e30a1f60f783 114 pos = bin;
mjr 86:e30a1f60f783 115 return true;
mjr 86:e30a1f60f783 116 }
mjr 86:e30a1f60f783 117
mjr 86:e30a1f60f783 118 // no code found
mjr 82:4f6209cb5c33 119 return false;
mjr 86:e30a1f60f783 120
mjr 86:e30a1f60f783 121 #else
mjr 86:e30a1f60f783 122 int barStart = leftBarMaxOfs/2;
mjr 86:e30a1f60f783 123 if (leftBarWidth != 0) // $$$
mjr 86:e30a1f60f783 124 {
mjr 86:e30a1f60f783 125 // Find the black bar on the left side (nearest pixel 0) that
mjr 86:e30a1f60f783 126 // delimits the start of the bar code. To find it, first figure
mjr 86:e30a1f60f783 127 // the average brightness over the left margin up to the maximum
mjr 86:e30a1f60f783 128 // allowable offset, then look for the bar by finding the first
mjr 86:e30a1f60f783 129 // bar-width run of pixels that are darker than the average.
mjr 86:e30a1f60f783 130 int lsum = 0;
mjr 86:e30a1f60f783 131 for (int x = 1 ; x <= leftBarMaxOfs ; ++x)
mjr 86:e30a1f60f783 132 lsum += pix[x];
mjr 86:e30a1f60f783 133 int lavg = lsum / leftBarMaxOfs;
mjr 86:e30a1f60f783 134
mjr 86:e30a1f60f783 135 // now find the first dark edge
mjr 86:e30a1f60f783 136 for (int x = 0 ; x < leftBarMaxOfs ; ++x)
mjr 86:e30a1f60f783 137 {
mjr 86:e30a1f60f783 138 // if this pixel is dark, and one of the next two is dark,
mjr 86:e30a1f60f783 139 // take it as the edge
mjr 86:e30a1f60f783 140 if (pix[x] < lavg && (pix[x+1] < lavg || pix[x+2] < lavg))
mjr 86:e30a1f60f783 141 {
mjr 86:e30a1f60f783 142 // move past the delimier
mjr 86:e30a1f60f783 143 barStart = x + leftBarWidth;
mjr 86:e30a1f60f783 144 break;
mjr 86:e30a1f60f783 145 }
mjr 86:e30a1f60f783 146 }
mjr 86:e30a1f60f783 147 }
mjr 86:e30a1f60f783 148 else
mjr 86:e30a1f60f783 149 {
mjr 86:e30a1f60f783 150 barStart = 4; // $$$ should be configurable via config tool
mjr 86:e30a1f60f783 151 }
mjr 86:e30a1f60f783 152
mjr 86:e30a1f60f783 153 // Scan the bits
mjr 86:e30a1f60f783 154 int barcode = 0;
mjr 86:e30a1f60f783 155 for (int bit = 0, x0 = barStart; bit < nBits ; ++bit, x0 += bitWidth)
mjr 86:e30a1f60f783 156 {
mjr 86:e30a1f60f783 157 // figure the extent of this bit
mjr 86:e30a1f60f783 158 int x1 = x0 + bitWidth / 2;
mjr 86:e30a1f60f783 159 int x2 = x0 + bitWidth;
mjr 86:e30a1f60f783 160 if (x1 > npix) x1 = npix;
mjr 86:e30a1f60f783 161 if (x2 > npix) x2 = npix;
mjr 86:e30a1f60f783 162
mjr 86:e30a1f60f783 163 // get the average of the pixels over the bit
mjr 86:e30a1f60f783 164 int sum = 0;
mjr 86:e30a1f60f783 165 for (int x = x0 ; x < x2 ; ++x)
mjr 86:e30a1f60f783 166 sum += pix[x];
mjr 86:e30a1f60f783 167 int avg = sum / bitWidth;
mjr 86:e30a1f60f783 168
mjr 86:e30a1f60f783 169 // Scan the left and right sections. Classify each
mjr 86:e30a1f60f783 170 // section according to whether the majority of its
mjr 86:e30a1f60f783 171 // pixels are above or below the local average.
mjr 86:e30a1f60f783 172 int lsum = 0, rsum = 0;
mjr 86:e30a1f60f783 173 for (int x = x0 + 1 ; x < x1 - 1 ; ++x)
mjr 86:e30a1f60f783 174 lsum += (pix[x] < avg ? 0 : 1);
mjr 86:e30a1f60f783 175 for (int x = x1 + 1 ; x < x2 - 1 ; ++x)
mjr 86:e30a1f60f783 176 rsum += (pix[x] < avg ? 0 : 1);
mjr 86:e30a1f60f783 177
mjr 86:e30a1f60f783 178 // if we don't have a winner, fail
mjr 86:e30a1f60f783 179 if (lsum == rsum)
mjr 86:e30a1f60f783 180 return false;
mjr 86:e30a1f60f783 181
mjr 86:e30a1f60f783 182 // black/white = 0, white/black = 1
mjr 86:e30a1f60f783 183 barcode = (barcode << 1) | (lsum < rsum ? 0 : 1);
mjr 86:e30a1f60f783 184 }
mjr 86:e30a1f60f783 185
mjr 86:e30a1f60f783 186 // decode the Gray code value to binary
mjr 86:e30a1f60f783 187 pos = grayToBin(barcode);
mjr 86:e30a1f60f783 188
mjr 86:e30a1f60f783 189 // success
mjr 86:e30a1f60f783 190 return true;
mjr 86:e30a1f60f783 191 #endif
mjr 86:e30a1f60f783 192 }
mjr 86:e30a1f60f783 193
mjr 86:e30a1f60f783 194 // read a bar starting at the given pixel
mjr 86:e30a1f60f783 195 int readBit8(const uint8_t *pix)
mjr 86:e30a1f60f783 196 {
mjr 86:e30a1f60f783 197 // pull out the pixels for the bar
mjr 86:e30a1f60f783 198 uint8_t s[8];
mjr 86:e30a1f60f783 199 memcpy(s, pix, 8);
mjr 86:e30a1f60f783 200
mjr 86:e30a1f60f783 201 // sort them in brightness order (using an 8-element network sort)
mjr 86:e30a1f60f783 202 #define SWAP(a, b) if (s[a] > s[b]) { uint8_t tmp = s[a]; s[a] = s[b]; s[b] = tmp; }
mjr 86:e30a1f60f783 203 SWAP(0, 1);
mjr 86:e30a1f60f783 204 SWAP(2, 3);
mjr 86:e30a1f60f783 205 SWAP(0, 2);
mjr 86:e30a1f60f783 206 SWAP(1, 3);
mjr 86:e30a1f60f783 207 SWAP(1, 2);
mjr 86:e30a1f60f783 208 SWAP(4, 5);
mjr 86:e30a1f60f783 209 SWAP(6, 7);
mjr 86:e30a1f60f783 210 SWAP(4, 6);
mjr 86:e30a1f60f783 211 SWAP(5, 7);
mjr 86:e30a1f60f783 212 SWAP(5, 6);
mjr 86:e30a1f60f783 213 SWAP(0, 4);
mjr 86:e30a1f60f783 214 SWAP(1, 5);
mjr 86:e30a1f60f783 215 SWAP(1, 4);
mjr 86:e30a1f60f783 216 SWAP(2, 6);
mjr 86:e30a1f60f783 217 SWAP(3, 7);
mjr 86:e30a1f60f783 218 SWAP(3, 6);
mjr 86:e30a1f60f783 219 SWAP(2, 4);
mjr 86:e30a1f60f783 220 SWAP(3, 5);
mjr 86:e30a1f60f783 221 SWAP(3, 4);
mjr 86:e30a1f60f783 222 #undef SWAP
mjr 86:e30a1f60f783 223
mjr 86:e30a1f60f783 224 // figure the median brightness
mjr 86:e30a1f60f783 225 int median = (int(s[3]) + s[4] + 1) / 2;
mjr 86:e30a1f60f783 226
mjr 86:e30a1f60f783 227 // count pixels below the median on each side
mjr 86:e30a1f60f783 228 int ldark = 0, rdark = 0;
mjr 86:e30a1f60f783 229 for (int i = 0 ; i < 3 ; ++i)
mjr 86:e30a1f60f783 230 {
mjr 86:e30a1f60f783 231 if (pix[i] < median)
mjr 86:e30a1f60f783 232 ldark++;
mjr 86:e30a1f60f783 233 }
mjr 86:e30a1f60f783 234 for (int i = 4 ; i < 8 ; ++i)
mjr 86:e30a1f60f783 235 {
mjr 86:e30a1f60f783 236 if (pix[i] < median)
mjr 86:e30a1f60f783 237 rdark++;
mjr 86:e30a1f60f783 238 }
mjr 86:e30a1f60f783 239
mjr 86:e30a1f60f783 240 // we need >=3 dark + >=3 light or vice versa
mjr 86:e30a1f60f783 241 if (ldark >= 3 && rdark <= 1)
mjr 86:e30a1f60f783 242 {
mjr 86:e30a1f60f783 243 // dark + light = '0' bit
mjr 86:e30a1f60f783 244 return 0;
mjr 86:e30a1f60f783 245 }
mjr 86:e30a1f60f783 246 if (ldark <= 1 && rdark >= 3)
mjr 86:e30a1f60f783 247 {
mjr 86:e30a1f60f783 248 // light + dark = '1' bit
mjr 86:e30a1f60f783 249 return 1;
mjr 86:e30a1f60f783 250 }
mjr 86:e30a1f60f783 251 else
mjr 86:e30a1f60f783 252 {
mjr 86:e30a1f60f783 253 // ambiguous bit
mjr 86:e30a1f60f783 254 return -1;
mjr 86:e30a1f60f783 255 }
mjr 86:e30a1f60f783 256 }
mjr 86:e30a1f60f783 257
mjr 86:e30a1f60f783 258 // convert a reflected Gray code value (up to 16 bits) to binary
mjr 86:e30a1f60f783 259 int grayToBin(int grayval)
mjr 86:e30a1f60f783 260 {
mjr 86:e30a1f60f783 261 int temp = grayval ^ (grayval >> 8);
mjr 86:e30a1f60f783 262 temp ^= (temp >> 4);
mjr 86:e30a1f60f783 263 temp ^= (temp >> 2);
mjr 86:e30a1f60f783 264 temp ^= (temp >> 1);
mjr 86:e30a1f60f783 265 return temp;
mjr 82:4f6209cb5c33 266 }
mjr 82:4f6209cb5c33 267 };
mjr 82:4f6209cb5c33 268
mjr 86:e30a1f60f783 269 // Auto-exposure counter
mjr 86:e30a1f60f783 270 class BarCodeExposureCounter
mjr 86:e30a1f60f783 271 {
mjr 86:e30a1f60f783 272 public:
mjr 86:e30a1f60f783 273 BarCodeExposureCounter()
mjr 86:e30a1f60f783 274 {
mjr 86:e30a1f60f783 275 nDark = 0;
mjr 86:e30a1f60f783 276 nBright = 0;
mjr 86:e30a1f60f783 277 nZero = 0;
mjr 86:e30a1f60f783 278 nSat = 0;
mjr 86:e30a1f60f783 279 }
mjr 86:e30a1f60f783 280
mjr 86:e30a1f60f783 281 inline void count(int pix)
mjr 86:e30a1f60f783 282 {
mjr 86:e30a1f60f783 283 if (pix <= 2)
mjr 86:e30a1f60f783 284 ++nZero;
mjr 86:e30a1f60f783 285 else if (pix < 12)
mjr 86:e30a1f60f783 286 ++nDark;
mjr 86:e30a1f60f783 287 else if (pix >= 253)
mjr 86:e30a1f60f783 288 ++nSat;
mjr 86:e30a1f60f783 289 else if (pix > 200)
mjr 86:e30a1f60f783 290 ++nBright;
mjr 86:e30a1f60f783 291 }
mjr 86:e30a1f60f783 292
mjr 86:e30a1f60f783 293 int nDark; // dark pixels
mjr 86:e30a1f60f783 294 int nBright; // bright pixels
mjr 86:e30a1f60f783 295 int nZero; // pixels at zero brightness
mjr 86:e30a1f60f783 296 int nSat; // pixels at full saturation
mjr 86:e30a1f60f783 297 };
mjr 86:e30a1f60f783 298
mjr 86:e30a1f60f783 299 // PlungerSensor interface implementation for bar code readers.
mjr 86:e30a1f60f783 300 //
mjr 86:e30a1f60f783 301 // Bar code readers are image sensors, so we have a pixel size for
mjr 86:e30a1f60f783 302 // the sensor. However, this isn't the scale for the readings. The
mjr 86:e30a1f60f783 303 // scale for the readings is determined by the number of bits in the
mjr 86:e30a1f60f783 304 // bar code, since an n-bit bar code can encode 2^n distinct positions.
mjr 86:e30a1f60f783 305 //
mjr 86:e30a1f60f783 306 template <int nBits, int leftBarWidth, int leftBarMaxOfs, int bitWidth>
mjr 86:e30a1f60f783 307 class PlungerSensorBarCodeTSL14xx: public PlungerSensorTSL14xxSmall,
mjr 86:e30a1f60f783 308 PlungerSensorBarCode<nBits, leftBarWidth, leftBarMaxOfs, bitWidth>
mjr 82:4f6209cb5c33 309 {
mjr 82:4f6209cb5c33 310 public:
mjr 82:4f6209cb5c33 311 PlungerSensorBarCodeTSL14xx(int nativePix, PinName si, PinName clock, PinName ao)
mjr 86:e30a1f60f783 312 : PlungerSensorTSL14xxSmall(nativePix, (1 << nBits) - 1, si, clock, ao)
mjr 82:4f6209cb5c33 313 {
mjr 86:e30a1f60f783 314 // the native scale is the number of positions we can
mjr 86:e30a1f60f783 315 // encode in the bar code
mjr 86:e30a1f60f783 316 nativeScale = 1023;
mjr 82:4f6209cb5c33 317 }
mjr 82:4f6209cb5c33 318
mjr 82:4f6209cb5c33 319 protected:
mjr 86:e30a1f60f783 320
mjr 82:4f6209cb5c33 321 // process the image through the bar code reader
mjr 82:4f6209cb5c33 322 virtual bool process(const uint8_t *pix, int npix, int &pos)
mjr 82:4f6209cb5c33 323 {
mjr 82:4f6209cb5c33 324 // adjust the exposure
mjr 82:4f6209cb5c33 325 adjustExposure(pix, npix);
mjr 82:4f6209cb5c33 326
mjr 82:4f6209cb5c33 327 // do the standard bar code processing
mjr 86:e30a1f60f783 328 return PlungerSensorBarCode<nBits, leftBarWidth, leftBarMaxOfs, bitWidth>
mjr 86:e30a1f60f783 329 ::process(pix, npix, pos);
mjr 82:4f6209cb5c33 330 }
mjr 82:4f6209cb5c33 331
mjr 86:e30a1f60f783 332 // bar code sensor orientation is fixed
mjr 86:e30a1f60f783 333 virtual int getOrientation() const { return 1; }
mjr 86:e30a1f60f783 334
mjr 82:4f6209cb5c33 335 // adjust the exposure
mjr 82:4f6209cb5c33 336 void adjustExposure(const uint8_t *pix, int npix)
mjr 82:4f6209cb5c33 337 {
mjr 86:e30a1f60f783 338 #if 1
mjr 86:e30a1f60f783 339 // The Manchester code has a nice property for auto exposure
mjr 86:e30a1f60f783 340 // control: each bit area has equal numbers of white and black
mjr 86:e30a1f60f783 341 // pixels. So we know exactly how the overall population of
mjr 86:e30a1f60f783 342 // pixels has to look: the bit area will be 50% black and 50%
mjr 86:e30a1f60f783 343 // white, and the margins will be all white. For maximum
mjr 86:e30a1f60f783 344 // contrast, target an exposure level where the black pixels
mjr 86:e30a1f60f783 345 // are all below the middle brightness level and the white
mjr 86:e30a1f60f783 346 // pixels are all above. Start by figuring the number of
mjr 86:e30a1f60f783 347 // pixels above and below.
mjr 86:e30a1f60f783 348 int nDark = 0;
mjr 86:e30a1f60f783 349 for (int i = 0 ; i < npix ; ++i)
mjr 86:e30a1f60f783 350 {
mjr 86:e30a1f60f783 351 if (pix[i] < 200)
mjr 86:e30a1f60f783 352 ++nDark;
mjr 86:e30a1f60f783 353 }
mjr 86:e30a1f60f783 354
mjr 86:e30a1f60f783 355 // Figure the percentage of black pixels: the left bar is
mjr 86:e30a1f60f783 356 // all black pixels, and 50% of each bit is black pixels.
mjr 86:e30a1f60f783 357 int targetDark = leftBarWidth + (nBits * bitWidth)/2;
mjr 86:e30a1f60f783 358
mjr 86:e30a1f60f783 359 // Increase exposure time if too many pixels are below the
mjr 86:e30a1f60f783 360 // halfway point; decrease it if too many pixels are above.
mjr 86:e30a1f60f783 361 int d = nDark - targetDark;
mjr 86:e30a1f60f783 362 if (d > 5 || d < -5)
mjr 86:e30a1f60f783 363 {
mjr 86:e30a1f60f783 364 axcTime += d;
mjr 86:e30a1f60f783 365 }
mjr 86:e30a1f60f783 366
mjr 86:e30a1f60f783 367
mjr 86:e30a1f60f783 368 #elif 0 //$$$
mjr 86:e30a1f60f783 369 // Count exposure levels of pixels in the left and right margins
mjr 86:e30a1f60f783 370 BarCodeExposureCounter counter;
mjr 86:e30a1f60f783 371 for (int i = 0 ; i < leftBarMaxOfs/2 ; ++i)
mjr 86:e30a1f60f783 372 {
mjr 86:e30a1f60f783 373 // count the pixels at the left and right margins
mjr 86:e30a1f60f783 374 counter.count(pix[i]);
mjr 86:e30a1f60f783 375 counter.count(pix[npix - i - 1]);
mjr 86:e30a1f60f783 376 }
mjr 86:e30a1f60f783 377
mjr 86:e30a1f60f783 378 // The margin is all white, so try to get all of these pixels
mjr 86:e30a1f60f783 379 // in the bright range, but not saturated. That should give us
mjr 86:e30a1f60f783 380 // the best overall contrast throughout the image.
mjr 86:e30a1f60f783 381 if (counter.nSat > 0)
mjr 86:e30a1f60f783 382 {
mjr 86:e30a1f60f783 383 // overexposed - reduce exposure time
mjr 86:e30a1f60f783 384 if (axcTime > 5)
mjr 86:e30a1f60f783 385 axcTime -= 5;
mjr 86:e30a1f60f783 386 else
mjr 86:e30a1f60f783 387 axcTime = 0;
mjr 86:e30a1f60f783 388 }
mjr 86:e30a1f60f783 389 else if (counter.nBright < leftBarMaxOfs)
mjr 86:e30a1f60f783 390 {
mjr 86:e30a1f60f783 391 // they're not all in the bright range - increase exposure time
mjr 86:e30a1f60f783 392 axcTime += 5;
mjr 86:e30a1f60f783 393 }
mjr 86:e30a1f60f783 394
mjr 86:e30a1f60f783 395 #else // $$$
mjr 82:4f6209cb5c33 396 // Count the number of pixels near total darkness and
mjr 82:4f6209cb5c33 397 // total saturation
mjr 86:e30a1f60f783 398 int nZero = 0, nDark = 0, nBri = 0, nSat = 0;
mjr 82:4f6209cb5c33 399 for (int i = 0 ; i < npix ; ++i)
mjr 82:4f6209cb5c33 400 {
mjr 82:4f6209cb5c33 401 int pi = pix[i];
mjr 86:e30a1f60f783 402 if (pi <= 2)
mjr 86:e30a1f60f783 403 ++nZero;
mjr 86:e30a1f60f783 404 else if (pi < 12)
mjr 82:4f6209cb5c33 405 ++nDark;
mjr 86:e30a1f60f783 406 else if (pi >= 254)
mjr 82:4f6209cb5c33 407 ++nSat;
mjr 86:e30a1f60f783 408 else if (pi > 242)
mjr 86:e30a1f60f783 409 ++nBri;
mjr 82:4f6209cb5c33 410 }
mjr 82:4f6209cb5c33 411
mjr 82:4f6209cb5c33 412 // If more than 30% of pixels are near total darkness, increase
mjr 82:4f6209cb5c33 413 // the exposure time. If more than 30% are near total saturation,
mjr 82:4f6209cb5c33 414 // decrease the exposure time.
mjr 86:e30a1f60f783 415 int pct5 = uint32_t(npix * 3277) >> 16;
mjr 82:4f6209cb5c33 416 int pct30 = uint32_t(npix * 19661) >> 16;
mjr 82:4f6209cb5c33 417 int pct50 = uint32_t(npix) >> 1;
mjr 86:e30a1f60f783 418 if (nSat == 0)
mjr 86:e30a1f60f783 419 {
mjr 86:e30a1f60f783 420 // no saturated pixels - increase exposure time
mjr 86:e30a1f60f783 421 axcTime += 5;
mjr 86:e30a1f60f783 422 }
mjr 86:e30a1f60f783 423 else if (nSat > pct5)
mjr 86:e30a1f60f783 424 {
mjr 86:e30a1f60f783 425 if (axcTime > 5)
mjr 86:e30a1f60f783 426 axcTime -= 5;
mjr 86:e30a1f60f783 427 else
mjr 86:e30a1f60f783 428 axcTime = 0;
mjr 86:e30a1f60f783 429 }
mjr 86:e30a1f60f783 430 else if (nZero == 0)
mjr 86:e30a1f60f783 431 {
mjr 86:e30a1f60f783 432 // no totally dark pixels - decrease exposure time
mjr 86:e30a1f60f783 433 if (axcTime > 5)
mjr 86:e30a1f60f783 434 axcTime -= 5;
mjr 86:e30a1f60f783 435 else
mjr 86:e30a1f60f783 436 axcTime = 0;
mjr 86:e30a1f60f783 437 }
mjr 86:e30a1f60f783 438 else if (nZero > pct5)
mjr 86:e30a1f60f783 439 {
mjr 86:e30a1f60f783 440 axcTime += 5;
mjr 86:e30a1f60f783 441 }
mjr 86:e30a1f60f783 442 else if (nZero > pct30 || (nDark > pct50 && nSat < pct30))
mjr 82:4f6209cb5c33 443 {
mjr 82:4f6209cb5c33 444 // very dark - increase exposure time a lot
mjr 82:4f6209cb5c33 445 if (axcTime < 450)
mjr 82:4f6209cb5c33 446 axcTime += 50;
mjr 82:4f6209cb5c33 447 }
mjr 82:4f6209cb5c33 448 else if (nDark > pct30 && nSat < pct30)
mjr 82:4f6209cb5c33 449 {
mjr 82:4f6209cb5c33 450 // dark - increase exposure time a bit
mjr 82:4f6209cb5c33 451 if (axcTime < 490)
mjr 82:4f6209cb5c33 452 axcTime += 10;
mjr 82:4f6209cb5c33 453 }
mjr 86:e30a1f60f783 454 else if (nSat > pct30 || (nBri > pct50 && nDark < pct30))
mjr 82:4f6209cb5c33 455 {
mjr 82:4f6209cb5c33 456 // very overexposed - decrease exposure time a lot
mjr 82:4f6209cb5c33 457 if (axcTime > 50)
mjr 82:4f6209cb5c33 458 axcTime -= 50;
mjr 82:4f6209cb5c33 459 else
mjr 82:4f6209cb5c33 460 axcTime = 0;
mjr 82:4f6209cb5c33 461 }
mjr 86:e30a1f60f783 462 else if (nBri > pct30 && nDark < pct30)
mjr 82:4f6209cb5c33 463 {
mjr 82:4f6209cb5c33 464 // overexposed - decrease exposure time a little
mjr 82:4f6209cb5c33 465 if (axcTime > 10)
mjr 82:4f6209cb5c33 466 axcTime -= 10;
mjr 82:4f6209cb5c33 467 else
mjr 82:4f6209cb5c33 468 axcTime = 0;
mjr 82:4f6209cb5c33 469 }
mjr 86:e30a1f60f783 470 #endif
mjr 86:e30a1f60f783 471
mjr 86:e30a1f60f783 472 // don't allow the exposure time to go over 2.5ms
mjr 86:e30a1f60f783 473 if (int(axcTime) < 0)
mjr 86:e30a1f60f783 474 axcTime = 0;
mjr 86:e30a1f60f783 475 if (axcTime > 2500)
mjr 86:e30a1f60f783 476 axcTime = 2500;
mjr 82:4f6209cb5c33 477 }
mjr 82:4f6209cb5c33 478 };
mjr 82:4f6209cb5c33 479
mjr 86:e30a1f60f783 480 // TSL1401CL - 128-bit image sensor, used as a bar code reader
mjr 86:e30a1f60f783 481 class PlungerSensorTSL1401CL: public PlungerSensorBarCodeTSL14xx<
mjr 86:e30a1f60f783 482 10, // number of bits in code
mjr 86:e30a1f60f783 483 0, // left delimiter bar width in pixels (0 for none)
mjr 86:e30a1f60f783 484 24, // maximum left margin width in pixels
mjr 86:e30a1f60f783 485 12> // pixel width of each bit
mjr 82:4f6209cb5c33 486 {
mjr 82:4f6209cb5c33 487 public:
mjr 82:4f6209cb5c33 488 PlungerSensorTSL1401CL(PinName si, PinName clock, PinName a0)
mjr 82:4f6209cb5c33 489 : PlungerSensorBarCodeTSL14xx(128, si, clock, a0)
mjr 82:4f6209cb5c33 490 {
mjr 82:4f6209cb5c33 491 }
mjr 82:4f6209cb5c33 492 };
mjr 82:4f6209cb5c33 493
mjr 82:4f6209cb5c33 494 #endif