FAQ

READ FIRST

README of top directory : https://github.com/tmk/tmk_keyboard/blob/master/README.md
README of target project(keyboard/converter) directory.

Note that you'll need to read both.

Can TMK do ***?

TMK may be not itself enough for your need but C/C++ can do anything you want :D

Build

FAQ/Build

Keymap

FAQ/Keymap

Debug Console

Get hid_listen

Download it from PJRC page.

hid_listen can't recognize device

When debug console of your device is not ready you will see like this:

Waiting for device:.........

once the device is pluged in then hid_listen finds it you will get this message:

Waiting for new device:.........................
Listening:

Check if you can't get this 'Listening:' message:

build with CONSOLE_ENABLE=yes in Makefile.

You may need privilege to access the device on OS like Linux.

try sudo hid_listen

Can't get message on console

Check the following:

Make sure hid_listen finds your device. See above.
Enable debug by pressing Magic+d. See Magic Commands.
Set debug_enable=true, usually in matrix_init() in matrix.c in your project directory.
Try using the 'print' function instead of debug print. See common/print.h.
Disconnect other devices with console function. See Issue #97.
Note that debug/print output will not appear in hid_listen during matrix_init(), or at any time prior to Boot Magic initialization.
make sure you have connected the pins either according to instructions or changed pin/port number and interrupts in config.h (see here).

Linux or UNIX like system requires Super User privilege

Just use 'sudo' to execute hid_listen with privilege.

$ sudo hid_listen

Or add an udev rule for TMK devices with placing a file in rules directory. The directory may vary on each system.

File: /etc/udev/rules.d/52-tmk-keyboard.rules(in case of Ubuntu)

# tmk keyboard products     https://github.com/tmk/tmk_keyboard
SUBSYSTEMS=="usb", ATTRS{idVendor}=="feed", MODE:="0666"

Console output lost

Blocking main loop long may prevent console from printing message.

Miscellaneous

NKRO Doesn't work

First you have to compile firmware with this build option NKRO_ENABLE in Makefile.

Try Magic N command(LShift+RShift+N by default) when NKRO still doesn't work. You can use this command to toggle between NKRO and 6KRO mode temporarily. In some situations NKRO doesn't work you need to switch to 6KRO mode, in particular when you are in BIOS.

If your firmware built with BOOTMAGIC_ENABLE you need to turn its switch on by BootMagic N command(Space+N by default). This setting is stored in EEPROM and keeped over power cycles.

https://github.com/tmk/tmk_keyboard#boot-magic-configuration---virtual-dip-switch

TrackPoint needs reset circuit(PS/2 mouse support)

Without reset circuit you will have inconsistent reuslt due to improper initialize of the hardware. See circuit schematic of TPM754.

Can't read column of matrix beyond 16

Use 1UL<<16 instead of 1<<16 in read_cols() in matrix.h when your columns goes beyond 16.

In C 1 means one of int type which is 16bit in case of AVR so you can't shift left more than 15. You will get unexpected zero when you say 1<<16. You have to use unsigned long type with 1UL.

Pull-up Resistor

Keyboard converter needs pull up resistor on signal lines in most cases. Without the pull-up resistors it may not work correctly.

Place the resistor between VCC and signal line like diagram below. In general 1K Ohm is recommended for keyboard converters. You can use 1/10W or higher power rating of resistor.

See this for more details.

IBMPC converter(for example):

Keyboard                                       MCU(AVR)
   -----.                                      ,-----.
      5V|------------------------------+--+----|VCC  |
        |                              |  |    |     |
        |                              R  R    |     |
        |                              |  |    |     |
    DATA|------------------------------|--+----|PD0  |
   CLOCK|------------------------------+-------|PD1  |
        |                                      |     |
     GND|--------------------------------------|GND  |
   -----'                                      `-----'
R: 1K-4.7K Ohm resistor

Consult with instructions of target converter.

Arduino Micro's pin naming is confusing

Note that Arduino Micro PCB marking is different from real AVR port name. D0 of Arduino Micro is not PD0, PD0 is D3. Check schematic yourself. http://arduino.cc/en/uploads/Main/arduino-micro-schematic.pdf

Bootloader jump doesn't work

Properly configure bootloader size in Makefile. With wrong section size bootloader won't probably start with Magic command and Boot Magic.

# Size of Bootloaders in bytes:
#   Atmel DFU loader(ATmega32U4)   4096    
#   Atmel DFU loader(AT90USB128)   8192    
#   LUFA bootloader(ATmega32U4)    4096             
#   Arduino Caterina(ATmega32U4)   4096             
#   USBaspLoader(ATmega***)        2048             
#   Teensy   halfKay(ATmega32U4)   512              
#   Teensy++ halfKay(AT90USB128)   2048
OPT_DEFS += -DBOOTLOADER_SIZE=4096

AVR Boot section size are defined by setting BOOTSZ fuse in fact. Consult with your MCU datasheet. Note that Word(2 bytes) size and address are used in datasheet while TMK uses Byte.

AVR Boot section is located at end of Flash memory like the followings.

byte     Atmel/LUFA(ATMega32u4)          byte     Atmel(AT90SUB1286)
0x0000   +---------------+               0x00000  +---------------+
         |               |                        |               |
         |               |                        |               |
         |  Application  |                        |  Application  |
         |               |                        |               | 
         =               =                        =               =
         |               | 32KB-4KB               |               | 128KB-8KB
0x6000   +---------------+               0x1E000  +---------------+
         |  Bootloader   | 4KB                    |  Bootloader   | 8KB
0x7FFF   +---------------+               0x1FFFF  +---------------+

 
byte     Teensy(ATMega32u4)              byte     Teensy++(AT90SUB1286)
0x0000   +---------------+               0x00000  +---------------+
         |               |                        |               |
         |               |                        |               |
         |  Application  |                        |  Application  |
         |               |                        |               |
         =               =                        =               =
         |               | 32KB-512B              |               | 128KB-2KB
0x7E00   +---------------+               0x1FC00  +---------------+
         |  Bootloader   | 512B                   |  Bootloader   | 2KB
0x7FFF   +---------------+               0x1FFFF  +---------------+

And see this discussion for further reference. https://github.com/tmk/tmk_keyboard/issues/179

Special Extra key doesn't work(System, Audio control keys)

You need to define EXTRAKEY_ENABLE in makefile to use them in TMK.

EXTRAKEY_ENABLE = yes          # Audio control and System control

http://deskthority.net/workshop-f7/tmk-keyboard-firmware-collection-t4478-60.html#p157919

Wakeup from sleep doesn't work

Basically you can get sleeping host wake by pressing any key.

In Windows check Allow this device to wake the computer setting in Power Management tab of Device Manager. Also check BIOS setting.

Using Arduino?

Note that Arduino pin naming is different from actual chip. For example, Arduino pin D0 is not PD0. Check circuit with its schematics yourself.

Arduino leonardo and micro have ATMega32U4 and can be used for TMK, though Arduino bootloader may be a problem.

Using PF4-7 pins of USB AVR?

You need to set JTD bit of MCUCR yourself to use PF4-7 as GPIO. Those pins are configured to serve JTAG function by default. MCUs like ATMegaU or AT90USB* are affeteced with this.

If you are using Teensy this isn't needed. Teensy is shipped with JTAGEN fuse bit unprogrammed to disable the function.

See this code.

    // JTAG disable for PORT F. write JTD bit twice within four cycles.
    MCUCR |= (1<<JTD);
    MCUCR |= (1<<JTD);

https://github.com/tmk/tmk_keyboard/blob/master/keyboard/hbkb/matrix.c#L67

And read 26.5.1 MCU Control Register – MCUCR of ATMega32U4 datasheet.

Adding LED indicators of Lock keys

You need your own LED indicators for CapsLock, ScrollLock and NumLock? See this post.

http://deskthority.net/workshop-f7/tmk-keyboard-firmware-collection-t4478-120.html#p191560

Program Arduino Micro/Leonardo

Push reset button and then run command like this within 8 seconds.

avrdude -patmega32u4 -cavr109 -b57600 -Uflash:w:adb_usb.hex -P/dev/ttyACM0

Device name will vary depending on your system.

http://arduino.cc/en/Main/ArduinoBoardMicro https://geekhack.org/index.php?topic=14290.msg1563867#msg1563867

USB 3 compatibility

I heard some people have a problem with USB 3 ports, try a USB 2 port or attach via a USB 2 hub.

Mac compatibility

OS X 10.11 and Hub

https://geekhack.org/index.php?topic=14290.msg1884034#msg1884034

Problem on BIOS(UEFI)/Resume(Sleep&Wake)/Power cycles

Some people reported their keyboard stops working on BIOS and/or after resume(power cycles).

As of now root of its cause is not clear but some build options seem to be related. In Makefile try to disable those options like CONSOLE_ENABLE, NKRO_ENABLE, SLEEP_LED_ENABLE and/or others.

https://github.com/tmk/tmk_keyboard/issues/266 https://geekhack.org/index.php?topic=41989.msg1967778#msg1967778

Desn't work with BIOS/EFI

Turn NKRO off by one of methods below.

Press Magic(LShift + RShift by default) + n
Build firmware with disabling NKRO in Makefile and flash it.

NKRO keyboard tends to work with some BIOS/EFI while not with others. 6KRO is likely to always work with most BIOS/EFI.

FLIP doesn't work

AtLibUsbDfu.dll not found

Remove current driver and reinstall one FLIP provides from DeviceManager. http://imgur.com/a/bnwzy

How to add extra button on PS/2 converter

Sorry if this was asked already, could you describe the steps needed to add two extra buttons to the ps2_usb tmk converter? Or is there some support already? I mean, buttons connected directly to some pins of the atmega32u4. Thanks!

https://geekhack.org/index.php?topic=72052.msg2630974#msg2630974

You can add your code in matrix_scan() function to scan the buttons. https://github.com/tmk/tmk_keyboard/blob/master/converter/ps2_usb/matrix.c#L144

The function is called repeatedly every so often in main loop and would be good place to add your code in this case. TMK converters translate scancode got from keyboard into key stataus as a bit in array matrix[].

I think you can add state of those buttons into the array matrix[] using scancodes unused in your keyboard, for example F13(0x08) and F14(0x10). Use 'matrix_make()andmatrix_break()to change status of the button, likematrix_make(0x08)` when it is pressed. https://github.com/tmk/tmk_keyboard/blob/master/converter/ps2_usb/matrix.c#L407-L423

Code by Laser

https://geekhack.org/index.php?topic=14618.msg2632125#msg2632125

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