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.

Sun Jan 28 00:33:38 2018 +0000
Change PWM cycle in GPIO feedback device outputs to 5ms/200Hz to reduce LED flicker

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mjr 77:0b96f6867312 1 // New PWM
mjr 77:0b96f6867312 2 //
mjr 77:0b96f6867312 3 // This is a replacement for the mbed PwmOut class. It's both stripped
mjr 77:0b96f6867312 4 // down and beefed up. It's stripped down to just the functionality we
mjr 77:0b96f6867312 5 // need in the Pinscape code, and to a purely KL25Z implementation, which
mjr 77:0b96f6867312 6 // allows for a smaller memory footprint per instance. It's beefed up to
mjr 77:0b96f6867312 7 // correct a number of problems in the mbed implementation.
mjr 77:0b96f6867312 8 //
mjr 77:0b96f6867312 9 // Note that this class isn't quite API-compatible with the mbed version.
mjr 77:0b96f6867312 10 // We make the channel/TPM unit structure explicit, and we put the period()
mjr 77:0b96f6867312 11 // method (to change the PWM cycle time) on the unit object rather than the
mjr 77:0b96f6867312 12 // channel. We do this to emphasize in the API that the period is a property
mjr 77:0b96f6867312 13 // of the unit (which contains multiple channels) rather than the channel.
mjr 77:0b96f6867312 14 // The mbed library is misleading when it pretends that the period is a
mjr 77:0b96f6867312 15 // property of the channel, since this confusingly suggests that a channel's
mjr 77:0b96f6867312 16 // period can be set independently. It can't; the period can only be set for
mjr 77:0b96f6867312 17 // the whole group of channels controlled by a unit.
mjr 77:0b96f6867312 18 //
mjr 77:0b96f6867312 19 // Improvements over the mbed version:
mjr 77:0b96f6867312 20 //
mjr 77:0b96f6867312 21 // 1. We provide an alternative, non-glitching version of write(). The mbed
mjr 77:0b96f6867312 22 // version of write(), and our default version with the same name, causes a
mjr 77:0b96f6867312 23 // glitch on every write by resetting the TPM counter, which cuts the cycle
mjr 77:0b96f6867312 24 // short and causes a momentary drop in brightness (from the short cycle)
mjr 77:0b96f6867312 25 // that's visible if an LED is connected. This is particularly noticeable
mjr 77:0b96f6867312 26 // when doing a series of rapid writes, such as when fading a light on or off.
mjr 77:0b96f6867312 27 //
mjr 77:0b96f6867312 28 // We offer a version of write() that doesn't reset the counter, avoiding the
mjr 77:0b96f6867312 29 // glitch. This version skips the counter reset that the default version does.
mjr 77:0b96f6867312 30 //
mjr 77:0b96f6867312 31 // But this must be used with caution, because there's a whole separate
mjr 77:0b96f6867312 32 // problem if you don't reset the counter, which is why the mbed library
mjr 77:0b96f6867312 33 // does this by default. The KL25Z hardware only allows the value register
mjr 77:0b96f6867312 34 // to be written once per PWM cycle; if it's written more than once, the
mjr 77:0b96f6867312 35 // second and subsequent writes are simply ignored, so those updates will
mjr 77:0b96f6867312 36 // be forever lost. The counter reset, in addition to casuing the glitch,
mjr 77:0b96f6867312 37 // resets the cycle and thus avoids the one-write-per-cycle limitation.
mjr 77:0b96f6867312 38 // Callers using the non-glitchy version must take care to time writes so
mjr 77:0b96f6867312 39 // that there's only one per PWM period. Or, alternatively, they can just
mjr 77:0b96f6867312 40 // be sure to repeat updates periodically to ensure that the last update is
mjr 77:0b96f6867312 41 // eventually applied.
mjr 77:0b96f6867312 42 //
mjr 77:0b96f6867312 43 // 2. We optimize the TPM clock pre-scaler to maximize the precision of the
mjr 77:0b96f6867312 44 // output period, to get as close as possible to the requested period. The
mjr 77:0b96f6867312 45 // base mbed code uses a fixed pre-scaler setting with a fixed 750kHz update
mjr 77:0b96f6867312 46 // frequency, which means the period can be set in 1.333us increments. The
mjr 77:0b96f6867312 47 // hardware is capable of increments as small as .02us. The tradeoff is that
mjr 77:0b96f6867312 48 // the higher precision modes with smaller increments only allow for limited
mjr 77:0b96f6867312 49 // total period lengths, since the cycle counter is 16 bits: the maximum
mjr 77:0b96f6867312 50 // period at a given clock increment is 65535 times the increment. So the
mjr 77:0b96f6867312 51 // mbed default of 1.333us increments allows for periods of up to 87ms with
mjr 77:0b96f6867312 52 // 1.333us precision, whereas the maximum precision of .02us increments only
mjr 77:0b96f6867312 53 // allows for a maximum period of 1.36ms.
mjr 77:0b96f6867312 54 //
mjr 77:0b96f6867312 55 // To deal with this tradeoff, we choose the scaling factor each time the
mjr 77:0b96f6867312 56 // period is changed, using the highest precision (smallest time increment,
mjr 77:0b96f6867312 57 // or lowest pre-scaling clock divider) available for the requested period.
mjr 77:0b96f6867312 58 //
mjr 77:0b96f6867312 59 // Similar variable pre-scaling functionality is available with the FastPWM
mjr 77:0b96f6867312 60 // class.
mjr 77:0b96f6867312 61 //
mjr 77:0b96f6867312 62 // 3. We properly handle the shared clock in the TPM units. The mbed library
mjr 77:0b96f6867312 63 // doesn't, nor does FastPWM.
mjr 77:0b96f6867312 64 //
mjr 77:0b96f6867312 65 // The period/frequency of a PWM channel on the KL25Z is a function of the
mjr 77:0b96f6867312 66 // TPM unit containing the channel, NOT of the channel itself. A channel's
mjr 77:0b96f6867312 67 // frequency CANNOT be set independently; it can only set for the entire
mjr 77:0b96f6867312 68 // group of channels controlled through the same TPM unit as the target
mjr 77:0b96f6867312 69 // channel.
mjr 77:0b96f6867312 70 //
mjr 77:0b96f6867312 71 // The mbed library and FastPWM library pretend that the period can be set
mjr 77:0b96f6867312 72 // per channel. This is misleading and bug-prone, since an application that
mjr 77:0b96f6867312 73 // takes the API at its word and sets a channel's frequency on the fly won't
mjr 77:0b96f6867312 74 // necessarily realize that it just changed the frequency for all of the other
mjr 77:0b96f6867312 75 // channels on the same TPM. What's more, the change in TPM period will
mjr 77:0b96f6867312 76 // effectively change the duty cycle for all channels attached to the PWM,
mjr 77:0b96f6867312 77 // since it'll update the counter modulus, so all channels on the same TPM
mjr 77:0b96f6867312 78 // have to have their duty cycles reset after any frequency change.
mjr 77:0b96f6867312 79 //
mjr 77:0b96f6867312 80 // This implementation changes the API design to better reflect reality. We
mjr 77:0b96f6867312 81 // expose a separate object representing the TPM unit for a channel, and we
mjr 77:0b96f6867312 82 // put the period update function on the TPM unit object rather than on the
mjr 77:0b96f6867312 83 // channel. We also automatically update the duty cycle variable for all
mjr 77:0b96f6867312 84 // channels on a TPM when updating the frequency, to maintain the original
mjr 77:0b96f6867312 85 // duty cycle (or as close as possible, after rounding error).
mjr 77:0b96f6867312 86 //
mjr 77:0b96f6867312 87 // Applications that need to control the duty cycle on more than one channel
mjr 77:0b96f6867312 88 // must take care to ensure that the separately controlled channels are on
mjr 77:0b96f6867312 89 // separate TPM units. The KL25Z offers three physical TPM units, so there
mjr 77:0b96f6867312 90 // can be up to three independently controlled periods. The KL25Z has 10
mjr 77:0b96f6867312 91 // channels in total (6 on unit 0, 2 on unit 1, 2 on unit 2), so the remaining
mjr 77:0b96f6867312 92 // 7 channels have to share their periods with their TPM unit-mates.
mjr 77:0b96f6867312 93
mjr 77:0b96f6867312 94
mjr 77:0b96f6867312 95 #ifndef _NEWPWMOUT_H_
mjr 77:0b96f6867312 96 #define _NEWPWMOUT_H_
mjr 77:0b96f6867312 97
mjr 77:0b96f6867312 98 #include <mbed.h>
mjr 77:0b96f6867312 99 #include <pinmap.h>
mjr 77:0b96f6867312 100 #include <PeripheralPins.h>
mjr 77:0b96f6867312 101 #include <clk_freqs.h>
mjr 77:0b96f6867312 102
mjr 77:0b96f6867312 103 // TPM Unit. This corresponds to one TPM unit in the hardware. Each
mjr 77:0b96f6867312 104 // unit controls 6 channels; a channel corresponds to one output pin.
mjr 77:0b96f6867312 105 // A unit contains the clock input, pre-scaler, counter, and counter
mjr 77:0b96f6867312 106 // modulus; these are shared among all 6 channels in the unit, and
mjr 77:0b96f6867312 107 // together determine the cycle time (period) of all channels in the
mjr 77:0b96f6867312 108 // unit. The period of a single channel can't be set independently;
mjr 77:0b96f6867312 109 // a channel takes its period from its unit.
mjr 77:0b96f6867312 110 //
mjr 77:0b96f6867312 111 // Since the KL25Z hardware has a fixed set of 3 TPM units, we have
mjr 77:0b96f6867312 112 // a fixed array of 3 of these objects.
mjr 77:0b96f6867312 113 class NewPwmUnit
mjr 77:0b96f6867312 114 {
mjr 77:0b96f6867312 115 public:
mjr 77:0b96f6867312 116 NewPwmUnit()
mjr 77:0b96f6867312 117 {
mjr 77:0b96f6867312 118 // figure our unit number from the singleton array position
mjr 77:0b96f6867312 119 int tpm_n = this - unit;
mjr 77:0b96f6867312 120
mjr 77:0b96f6867312 121 // start with all channels disabled
mjr 77:0b96f6867312 122 activeChannels = 0;
mjr 77:0b96f6867312 123
mjr 77:0b96f6867312 124 // get our TPM unit hardware register base
mjr 77:0b96f6867312 125 tpm = (TPM_Type *)(TPM0_BASE + 0x1000*tpm_n);
mjr 77:0b96f6867312 126
mjr 77:0b96f6867312 127 // Determine which clock input we're using. Save the clock
mjr 77:0b96f6867312 128 // frequency for later use when setting the PWM period, and
mjr 77:0b96f6867312 129 // set up the SIM control register for the appropriate clock
mjr 77:0b96f6867312 130 // input. This setting is global, so we really only need to
mjr 77:0b96f6867312 131 // do it once for all three units, but it'll be the same every
mjr 77:0b96f6867312 132 // time so it won't hurt (except for a little redundancy) to
mjr 77:0b96f6867312 133 // do it again on each unit constructor.
mjr 77:0b96f6867312 134 if (mcgpllfll_frequency()) {
mjr 77:0b96f6867312 135 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: MCGFLLCLK or MCGPLLCLK
mjr 77:0b96f6867312 136 sysClock = mcgpllfll_frequency();
mjr 77:0b96f6867312 137 } else {
mjr 77:0b96f6867312 138 SIM->SOPT2 |= SIM_SOPT2_TPMSRC(2); // Clock source: ExtOsc
mjr 77:0b96f6867312 139 sysClock = extosc_frequency();
mjr 77:0b96f6867312 140 }
mjr 77:0b96f6867312 141 }
mjr 77:0b96f6867312 142
mjr 77:0b96f6867312 143 // enable a channel
mjr 77:0b96f6867312 144 void enableChannel(int ch)
mjr 77:0b96f6867312 145 {
mjr 77:0b96f6867312 146 // if this is the first channel we're enabling, enable the
mjr 77:0b96f6867312 147 // unit clock gate
mjr 77:0b96f6867312 148 if (activeChannels == 0)
mjr 77:0b96f6867312 149 {
mjr 77:0b96f6867312 150 // enable the clock gate on the TPM unit
mjr 77:0b96f6867312 151 int tpm_n = this - unit;
mjr 77:0b96f6867312 152 SIM->SCGC6 |= 1 << (SIM_SCGC6_TPM0_SHIFT + tpm_n);
mjr 77:0b96f6867312 153
mjr 93:177832c29041 154 // set a default period of 20ms
mjr 77:0b96f6867312 155 period(20.0e-3f);
mjr 77:0b96f6867312 156 }
mjr 77:0b96f6867312 157
mjr 77:0b96f6867312 158 // add the channel bit to our collection
mjr 77:0b96f6867312 159 activeChannels |= (1 << ch);
mjr 77:0b96f6867312 160 }
mjr 77:0b96f6867312 161
mjr 77:0b96f6867312 162 // Set the period for the unit. This updates all channels associated
mjr 77:0b96f6867312 163 // with the unit so that their duty cycle is scaled properly to the
mjr 77:0b96f6867312 164 // period counter.
mjr 77:0b96f6867312 165 void period(float seconds)
mjr 77:0b96f6867312 166 {
mjr 77:0b96f6867312 167 // First check to see if we actually need to change anything. If
mjr 77:0b96f6867312 168 // the requested period already matches the current period, there's
mjr 77:0b96f6867312 169 // nothing to do. This will avoid unnecessarily resetting any
mjr 77:0b96f6867312 170 // running cycles, which could cause visible flicker.
mjr 77:0b96f6867312 171 uint32_t freq = sysClock >> (tpm->SC & TPM_SC_PS_MASK);
mjr 77:0b96f6867312 172 uint32_t oldMod = tpm->MOD;
mjr 77:0b96f6867312 173 uint32_t newMod = uint32_t(seconds*freq) - 1;
mjr 77:0b96f6867312 174 if (newMod == oldMod && (tpm->SC & TPM_SC_CMOD_MASK) == TPM_SC_CMOD(1))
mjr 77:0b96f6867312 175 return;
mjr 77:0b96f6867312 176
mjr 77:0b96f6867312 177 // Figure the minimum pre-scaler needed to allow this period. The
mjr 77:0b96f6867312 178 // unit counter is 16 bits, so the maximum cycle length is 65535
mjr 77:0b96f6867312 179 // ticks. One tick is the system clock tick time multiplied by
mjr 77:0b96f6867312 180 // the pre-scaler. The scaler comes in powers of two from 1 to 128.
mjr 77:0b96f6867312 181
mjr 77:0b96f6867312 182 // start at scaler=0 -> divide by 1
mjr 77:0b96f6867312 183 int ps = 0;
mjr 77:0b96f6867312 184 freq = sysClock;
mjr 77:0b96f6867312 185
mjr 77:0b96f6867312 186 // at this rate, the maximum period is 65535 ticks of the system clock
mjr 77:0b96f6867312 187 float pmax = 65535.0f/sysClock;
mjr 77:0b96f6867312 188
mjr 77:0b96f6867312 189 // Now figure how much we have to divide the system clock: each
mjr 77:0b96f6867312 190 // scaler step divides by another factor of 2, which doubles the
mjr 77:0b96f6867312 191 // maximum period. Keep going while the maximum period is below
mjr 77:0b96f6867312 192 // the desired period, but stop if we reach the maximum per-scale
mjr 77:0b96f6867312 193 // value of divide-by-128.
mjr 77:0b96f6867312 194 while (ps < 7 && pmax < seconds)
mjr 77:0b96f6867312 195 {
mjr 77:0b96f6867312 196 ++ps;
mjr 77:0b96f6867312 197 pmax *= 2.0f;
mjr 77:0b96f6867312 198 freq /= 2;
mjr 77:0b96f6867312 199 }
mjr 77:0b96f6867312 200
mjr 77:0b96f6867312 201 // Before writing the prescaler bits, we have to disable the
mjr 77:0b96f6867312 202 // clock (CMOD) bits in the status & control register. These
mjr 77:0b96f6867312 203 // bits might take a while to update, so spin until they clear.
mjr 77:0b96f6867312 204 while ((tpm->SC & 0x1F) != 0)
mjr 77:0b96f6867312 205 tpm->SC &= ~0x1F;
mjr 77:0b96f6867312 206
mjr 77:0b96f6867312 207 // Reset the CnV (trigger value) for all active channels to
mjr 77:0b96f6867312 208 // maintain each channel's current duty cycle.
mjr 77:0b96f6867312 209 for (int i = 0 ; i < 6 ; ++i)
mjr 77:0b96f6867312 210 {
mjr 77:0b96f6867312 211 // if this channel is active, reset it
mjr 77:0b96f6867312 212 if ((activeChannels & (1 << i)) != 0)
mjr 77:0b96f6867312 213 {
mjr 77:0b96f6867312 214 // figure the old duty cycle, based on the current
mjr 77:0b96f6867312 215 // channel value and the old modulus
mjr 77:0b96f6867312 216 uint32_t oldCnV = tpm->CONTROLS[i].CnV;
mjr 77:0b96f6867312 217 float dc = float(oldCnV)/float(oldMod + 1);
mjr 77:0b96f6867312 218 if (dc > 1.0f) dc = 1.0f;
mjr 77:0b96f6867312 219
mjr 77:0b96f6867312 220 // figure the new value that maintains the same duty
mjr 77:0b96f6867312 221 // cycle with the new modulus
mjr 77:0b96f6867312 222 uint32_t newCnV = uint32_t(dc*(newMod + 1));
mjr 77:0b96f6867312 223
mjr 77:0b96f6867312 224 // if it changed, write the new value
mjr 77:0b96f6867312 225 if (newCnV != oldCnV)
mjr 77:0b96f6867312 226 tpm->CONTROLS[i].CnV = newCnV;
mjr 77:0b96f6867312 227 }
mjr 77:0b96f6867312 228 }
mjr 77:0b96f6867312 229
mjr 77:0b96f6867312 230 // reset the unit counter register
mjr 77:0b96f6867312 231 tpm->CNT = 0;
mjr 77:0b96f6867312 232
mjr 77:0b96f6867312 233 // set the new clock period
mjr 77:0b96f6867312 234 tpm->MOD = newMod = uint32_t(seconds*freq) - 1;
mjr 77:0b96f6867312 235
mjr 77:0b96f6867312 236 // set the new pre-scaler bits and set clock mode 01 (enabled,
mjr 77:0b96f6867312 237 // increments on every LPTPM clock)
mjr 77:0b96f6867312 238 tpm->SC = TPM_SC_CMOD(1) | TPM_SC_PS(ps);
mjr 77:0b96f6867312 239 }
mjr 77:0b96f6867312 240
mjr 79:682ae3171a08 241 // wait for the end of the current cycle
mjr 79:682ae3171a08 242 void waitEndCycle()
mjr 79:682ae3171a08 243 {
mjr 79:682ae3171a08 244 // clear the overflow flag
mjr 79:682ae3171a08 245 tpm->SC |= TPM_SC_TOF_MASK;
mjr 79:682ae3171a08 246
mjr 79:682ae3171a08 247 // The flag will be set at the next overflow
mjr 79:682ae3171a08 248 while (!(tpm->SC & TPM_SC_TOF_MASK)) ;
mjr 79:682ae3171a08 249 }
mjr 79:682ae3171a08 250
mjr 77:0b96f6867312 251 // hardware register base
mjr 77:0b96f6867312 252 TPM_Type *tpm;
mjr 77:0b96f6867312 253
mjr 77:0b96f6867312 254 // Channels that are active in this unit, as a bit mask:
mjr 77:0b96f6867312 255 // 1<<n is our channel n.
mjr 77:0b96f6867312 256 uint8_t activeChannels;
mjr 77:0b96f6867312 257
mjr 77:0b96f6867312 258 // fixed array of unit singletons
mjr 77:0b96f6867312 259 static NewPwmUnit unit[3];
mjr 77:0b96f6867312 260
mjr 77:0b96f6867312 261 // system clock frequency
mjr 77:0b96f6867312 262 static uint32_t sysClock;
mjr 77:0b96f6867312 263 };
mjr 77:0b96f6867312 264
mjr 77:0b96f6867312 265
mjr 77:0b96f6867312 266 class NewPwmOut
mjr 77:0b96f6867312 267 {
mjr 77:0b96f6867312 268 public:
mjr 77:0b96f6867312 269 NewPwmOut(PinName pin)
mjr 77:0b96f6867312 270 {
mjr 77:0b96f6867312 271 // determine the TPM unit number and channel
mjr 77:0b96f6867312 272 PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
mjr 77:0b96f6867312 273 MBED_ASSERT(pwm != (PWMName)NC);
mjr 77:0b96f6867312 274 unsigned int port = (unsigned int)pin >> PORT_SHIFT;
mjr 77:0b96f6867312 275
mjr 77:0b96f6867312 276 // decode the port ID into the TPM unit and channel number
mjr 77:0b96f6867312 277 tpm_n = (pwm >> TPM_SHIFT);
mjr 77:0b96f6867312 278 ch_n = (pwm & 0xFF);
mjr 77:0b96f6867312 279
mjr 77:0b96f6867312 280 // enable the clock gate on the port (PTx)
mjr 77:0b96f6867312 281 SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
mjr 77:0b96f6867312 282
mjr 77:0b96f6867312 283 // enable the channel on the TPM unit
mjr 77:0b96f6867312 284 NewPwmUnit::unit[tpm_n].enableChannel(ch_n);
mjr 77:0b96f6867312 285
mjr 77:0b96f6867312 286 // set the channel control register:
mjr 77:0b96f6867312 287 // CHIE = 0 = interrupts disabled
mjr 77:0b96f6867312 288 // MSB:MBA:ELSB:ELSA = 1010 = edge-aligned PWM
mjr 77:0b96f6867312 289 // DMA = 0 = DMA off
mjr 77:0b96f6867312 290 TPM_Type *tpm = getUnit()->tpm;
mjr 77:0b96f6867312 291 tpm->CONTROLS[ch_n].CnSC = (TPM_CnSC_MSB_MASK | TPM_CnSC_ELSB_MASK);
mjr 77:0b96f6867312 292
mjr 77:0b96f6867312 293 // wire the pinout
mjr 77:0b96f6867312 294 pinmap_pinout(pin, PinMap_PWM);
mjr 77:0b96f6867312 295 }
mjr 77:0b96f6867312 296
mjr 77:0b96f6867312 297 float read()
mjr 77:0b96f6867312 298 {
mjr 77:0b96f6867312 299 TPM_Type *tpm = getUnit()->tpm;
mjr 77:0b96f6867312 300 float v = float(tpm->CONTROLS[ch_n].CnV)/float(tpm->MOD + 1);
mjr 77:0b96f6867312 301 return v > 1.0f ? 1.0f : v;
mjr 77:0b96f6867312 302 }
mjr 77:0b96f6867312 303
mjr 77:0b96f6867312 304 void write(float val)
mjr 77:0b96f6867312 305 {
mjr 77:0b96f6867312 306 // do the glitch-free write
mjr 77:0b96f6867312 307 glitchFreeWrite(val);
mjr 77:0b96f6867312 308
mjr 77:0b96f6867312 309 // Reset the counter. This is a workaround for a hardware problem
mjr 77:0b96f6867312 310 // on the KL25Z, namely that the CnV register can only be written
mjr 77:0b96f6867312 311 // once per PWM cycle. Any subsequent attempt to write it in the
mjr 77:0b96f6867312 312 // same cycle will be lost. Resetting the counter forces the end
mjr 77:0b96f6867312 313 // of the cycle and makes the register writable again. This isn't
mjr 77:0b96f6867312 314 // an ideal workaround because it causes visible brightness glitching
mjr 77:0b96f6867312 315 // if the caller writes new values repeatedly, such as when fading
mjr 77:0b96f6867312 316 // lights in or out.
mjr 77:0b96f6867312 317 TPM_Type *tpm = getUnit()->tpm;
mjr 77:0b96f6867312 318 tpm->CNT = 0;
mjr 77:0b96f6867312 319 }
mjr 77:0b96f6867312 320
mjr 77:0b96f6867312 321 // Write a new value without forcing the current PWM cycle to end.
mjr 77:0b96f6867312 322 // This results in glitch-free writing during fades or other series
mjr 77:0b96f6867312 323 // of rapid writes, BUT with the giant caveat that the caller MUST NOT
mjr 77:0b96f6867312 324 // write another value before the current PWM cycle ends. Doing so
mjr 77:0b96f6867312 325 // will cause the later write to be lost. Callers using this must
mjr 77:0b96f6867312 326 // take care, using mechanisms of their own, to limit writes to once
mjr 77:0b96f6867312 327 // per PWM cycle.
mjr 77:0b96f6867312 328 void glitchFreeWrite(float val)
mjr 77:0b96f6867312 329 {
mjr 77:0b96f6867312 330 // limit to 0..1 range
mjr 77:0b96f6867312 331 val = (val < 0.0f ? 0.0f : val > 1.0f ? 1.0f : val);
mjr 77:0b96f6867312 332
mjr 77:0b96f6867312 333 // Write the duty cycle register. The argument value is a duty
mjr 77:0b96f6867312 334 // cycle on a normalized 0..1 scale; for the hardware, we need to
mjr 77:0b96f6867312 335 // renormalize to the 0..MOD scale, where MOD is the cycle length
mjr 77:0b96f6867312 336 // in clock counts.
mjr 77:0b96f6867312 337 TPM_Type *tpm = getUnit()->tpm;
mjr 77:0b96f6867312 338 tpm->CONTROLS[ch_n].CnV = (uint32_t)((float)(tpm->MOD + 1) * val);
mjr 77:0b96f6867312 339 }
mjr 77:0b96f6867312 340
mjr 79:682ae3171a08 341 // Wait for the end of a cycle
mjr 79:682ae3171a08 342 void waitEndCycle() { getUnit()->waitEndCycle(); }
mjr 79:682ae3171a08 343
mjr 77:0b96f6867312 344 // Get my TPM unit object. This can be used to change the period.
mjr 77:0b96f6867312 345 inline NewPwmUnit *getUnit() { return &NewPwmUnit::unit[tpm_n]; }
mjr 77:0b96f6867312 346
mjr 77:0b96f6867312 347 protected:
mjr 77:0b96f6867312 348 // TPM unit number and channel number
mjr 77:0b96f6867312 349 uint8_t tpm_n;
mjr 77:0b96f6867312 350 uint8_t ch_n;
mjr 77:0b96f6867312 351 };
mjr 77:0b96f6867312 352
mjr 77:0b96f6867312 353 #endif