# Debugging FAQ
This page details various common questions people have about troubleshooting their keyboards.
# Debug Console
## `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 plugged in then *hid_listen* finds it you will get this message:
```
Waiting for new device:.........................
Listening:
```
If you can't get this 'Listening:' message try building 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:
- *hid_listen* finds your device. See above.
- Enable debug with pressing **Magic** +d. See [Magic Commands ](https://github.com/tmk/tmk_keyboard#magic-commands ).
- set `debug_enable=true` 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 ](https://github.com/tmk/tmk_keyboard/issues/97 ).
## 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"
```
***
# Miscellaneous
## Safety Considerations
You probably don't want to "brick" your keyboard, making it impossible
to rewrite firmware onto it. Here are some of the parameters to show
what things are (and likely aren't) too risky.
- If your keyboard map does not include RESET, then, to get into DFU
mode, you will need to press the reset button on the PCB, which
requires unscrewing the bottom.
- Messing with tmk_core / common files might make the keyboard
inoperable
- Too large a .hex file is trouble; `make dfu` will erase the block,
test the size (oops, wrong order!), which errors out, failing to
flash the keyboard, leaving it in DFU mode.
- To this end, note that the maximum .hex file size on Planck is
7000h (28672 decimal)
```
Linking: .build/planck_rev4_cbbrowne.elf [OK]
Creating load file for Flash: .build/planck_rev4_cbbrowne.hex [OK]
Size after:
text data bss dec hex filename
0 22396 0 22396 577c planck_rev4_cbbrowne.hex
```
- The above file is of size 22396/577ch, which is less than
28672/7000h
- As long as you have a suitable alternative .hex file around, you
can retry, loading that one
- Some of the options you might specify in your keyboard's Makefile
consume extra memory; watch out for BOOTMAGIC_ENABLE,
MOUSEKEY_ENABLE, EXTRAKEY_ENABLE, CONSOLE_ENABLE, API_SYSEX_ENABLE
- DFU tools do /not/ allow you to write into the bootloader (unless
you throw in extra fruit salad of options), so there is little risk
there.
- EEPROM has around a 100000 write cycle. You shouldn't rewrite the
firmware repeatedly and continually; that'll burn the EEPROM
eventually.
## 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 kept 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 result 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 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 [16 bit] 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
## 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
If you are using a TeensyUSB, there is a [known bug ](https://github.com/qmk/qmk_firmware/issues/164 ) in which the hardware reset button prevents the RESET key from working. Unplugging the keyboard and plugging it back in should resolve the problem.
## Special Extra Key Doesn't Work (System, Audio Control Keys)
You need to define `EXTRAKEY_ENABLE` in `rules.mk` to use them in QMK.
```
EXTRAKEY_ENABLE = yes # Audio control and System control
```
## 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.
## 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.
- http://arduino.cc/en/uploads/Main/arduino-leonardo-schematic_3b.pdf
- http://arduino.cc/en/uploads/Main/arduino-micro-schematic.pdf
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 ATMega*U* or AT90USB* are affected 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 – 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 port, try USB 2 port.
## 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
## FLIP Doesn't Work
### `AtLibUsbDfu.dll` Not Found
Remove current driver and reinstall one FLIP provides from DeviceManager.
http://imgur.com/a/bnwzy
