ErgoDox EZ
The Ez uses the Teensy Loader.
Linux users need to modify udev rules as described on the Teensy
Linux page.  Some distributions provide a binary, maybe called
teensy-loader-cli.
To flash the firmware:
- 
Build the firmware with make <keyboardname>:<keymapname>, for examplemake ergodox_ez:default
- 
This will result in a hex file called ergodox_ez_keymapname.hex, e.g.ergodox_ez_default.hex
- 
Start the teensy loader. 
- 
Load the .hex file into it. 
- 
Press the Reset button by inserting a paperclip gently into the reset hole in the top right corner. 
- 
Click the button in the Teensy app to download the firmware. 
See also video demonstration using Teensy in auto mode.
To flash with ´teensy-loader-cli´:
- 
Build the firmware with make keymapname, for examplemake default
- 
Run ´<path/to/>teensy_loader_cli -mmcu=atmega32u4 -w ergodox_ez_.hex´ 
- 
Press the Reset button by inserting a paperclip gently into the reset hole in the top right corder. 
Settings
You may want to enable QMK_KEYS_PER_SCAN because the Ergodox has a relatively slow scan rate.