qmk_firmware/FAQ.md

Build

'make clean' needs after changing config.h

To build with new config.h you need

$ make clean

WINAVR is obsolete

It is no longer recommended and may cause some problem. See Issue #99.

USB stack: LUFA or PJRC?

Use LUFA.

PJRC stack won't be supported actively anymore. There is no reason to hesitate to use LUFA except for binary size(about 1KB lager?). But PJRC is still very useful for debug and development purpose. See also Issue #50 and Issue #58.

Edit configuration but not change

Try these.

1. make clean

This will be needed when you edit config.h.

2. Remove Drivers from Device Manager(Windows)

Windows only. Linux, OSX and other OS's doesn't require this. It looks like Windows keeps using driver installed when device was connected first time even after the device changes its configuration. To load proper drivers for new configuration you need to remove existent drivers from Drvice Manager.

You will need this after editing CONSOLE_ENABLE, NKRO_ENABLE, EXTRAKEY_ENABLE or MOUSEKEY_ENABLE option in Makefile.

Degug Console

hid_listen can't find 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.

Can't get message from console

Check:

• connect the device to hid_listen. See above.
• push LShift+RShift+d to enable debug. See Magic Commands.
• set debug_enable=yes usually in matrix_init() in matrix.c.
• try using 'print' function instead of debug print. See common/print.h.
• disconnect other devices with console function. See Issue #97.

---

Miscellaneous

NKRO Doesn't work

Build with this option of Makefile

NKRO_ENABLE = yes

And use Magic command N to toggle NKRO feature. At this time NKRO is not used by default even if it is build with NKRO_ENABLE, you still need the Magic.

To turn on NKRO by default see this fix. https://github.com/shayneholmes/tmk_keyboard/commit/b8375a0

--- a/common/host.c
+++ b/common/host.c
@@ -24,7 +24,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
 #ifdef NKRO_ENABLE
-bool keyboard_nkro = false;
+bool keyboard_nkro = true;
 #endif
 
 static host_driver_t *driver;

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.

• http://geekhack.org/index.php?topic=50176.msg1127447#msg1127447
• http://www.mikrocontroller.net/attachment/52583/tpm754.pdf

Can't read comlumn of matrix beyond 16

Use 1UL<<16 intead 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.

http://deskthority.net/workshop-f7/rebuilding-and-redesigning-a-classic-thinkpad-keyboard-t6181-60.html#p146279

Pull-up Resistor

In some case converters needed to have pull-up resistors to work correctly. Place the resistor between VCC and signal line in parallel.

Keyboard       Conveter
               ,------.
5V------+------|VCC   |
        |      |      |
        R      |      |
        |      |      |
Signal--+------|PD0   |
               |      |
GND------------|GND   |
               `------'
R: 1K Ohm resistor

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

• https://github.com/tmk/tmk_keyboard#magic-commands
• https://github.com/tmk/tmk_keyboard#bootloader

# Boot Section Size in *bytes*
#   Teensy halfKay   512
#   Teensy++ halfKay 1024
#   Atmel DFU loader 4096       (TMK Alt Controller)
#   LUFA bootloader  4096
#   USBaspLoader     2048
OPT_DEFS += -DBOOTLOADER_SIZE=4096

http://geekhack.org/index.php?topic=12047.msg1292018#msg1292018

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

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

Pressing any key during sleep should wake host.