qmk-dactyl-manuform-a/Memory-write-error,-use-debug-for-more-info.md

In rare circumstances, your keyboard/device can become unwritable, and dfu-programmer will give you an error like this:

Erasing flash...  Success
Checking memory from 0x0 to 0x6FFF...  Empty.
Checking memory from 0x0 to 0x607F...  Empty.
0%                            100%  Programming 0x6080 bytes...
[ X  ERROR
Memory write error, use debug for more info.

Currently the only way to solve this is to reprogram the chip via ISP. This requires another device to be hooked-up to a couple exposed pins on the PCB. There is a guide on how to do this here, and this is where things are on the Planck PCB.

An example command to flash the board once things are hooked up is:

avrdude -c usbtiny -p m32u4 -U flash:w:planck_default_rev4.hex

Research is still being done on why this happens, but here are some cases:

• make -f Makefile.rn42 dfu and not the dfu-programmer commands worked for @tybenz - also see the hhkb keyboard on tmk
• Doing a force erase works here
• dfu-programmer atmega32u4 erase --force works here as well [DE]
• Unresolved, but some data dumps