TMK firmware programming & flashing

February 01, 2017

As part of my S60 custom mechanical keyboard build I had to program the firmware and flash the PCB.

I had a bit of trouble with this initially, so here is a guide below for anyone else that might need to do the same thing.

Step 1: Install 'dfu-programmer' via homebrew:

brew install dfu-programmer

Step 2: Install homebrew-avr so you can compile firmware:

brew tap osx-cross/avr
brew install avr-libc

Step 3: Grab the latest QMK source for the S60RGB here.

Step 4: Go to this folder, copy the keymap.c file into another folder in the /keymaps dir called custom for example.

Step 5: Make your edits.

My particular version was minor, I flipped right CTRL and FN buttons. I added up/left/down/right to WASD, and added audio mute, vol - and vol + to FN+1, FN+2, FN+3.

You can click here to find out what all the keycodes are.

Below is the default keymap, for reference.

#include "S60RGB.h"

// Used for SHIFT_ESC
#define MODS_CTRL_MASK  (MOD_BIT(KC_LSHIFT)|MOD_BIT(KC_RSHIFT))

// Each layer gets a name for readability, which is then used in the keymap matrix below.
// The underscores don't mean anything - you can have a layer called STUFF or any other name.
// Layer names don't all need to be of the same length, obviously, and you can also skip them
// entirely and just use numbers.
#define _BL 0
#define _FL 1

const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
  /* Keymap _BL: (Base Layer) Default Layer
   * ,-----------------------------------------------------------.
   * |Esc~| 1|  2|  3|  4|  5|  6|  7|  8|  9|  0|  -|  =|Backsp |
   * |-----------------------------------------------------------|
   * |Tab  |  Q|  W|  E|  R|  T|  Y|  U|  I|  O|  P|  [|  ]|  \  |
   * |-----------------------------------------------------------|
   * |CAPS   |  A|  S|  D|  F|  G|  H|  J|  K|  L|  ;|  '|Return |
   * |-----------------------------------------------------------|
   * |Shift   |  Z|  X|  C|  V|  B|  N|  M|  ,|  .|  /|Shift     |
   * |-----------------------------------------------------------|
   * |Ctrl|Gui |Alt |      Space            |Alt |Gui |FN  |Ctrl |
   * `-----------------------------------------------------------'
   */
[_BL] = KEYMAP(
  F(0),    KC_1,   KC_2,   KC_3,   KC_4,   KC_5,   KC_6,   KC_7,   KC_8,   KC_9,   KC_0,   KC_MINS,  KC_EQL,   KC_DEL, KC_BSPC, \
  KC_TAB,  KC_Q,   KC_W,   KC_E,   KC_R,   KC_T,   KC_Y,   KC_U,   KC_I,   KC_O,   KC_P,   KC_LBRC,  KC_RBRC,  KC_BSLS, \
  KC_CAPS,   KC_A,   KC_S,   KC_D,   KC_F,   KC_G,   KC_H,   KC_J,   KC_K,   KC_L,   KC_SCLN,KC_QUOT,            KC_ENT,  \
  KC_LSFT,         KC_Z,   KC_X,   KC_C,   KC_V,   KC_B,   KC_N,   KC_M,   KC_COMM,KC_DOT, KC_SLSH,            KC_RSFT,  \
  KC_LCTL, KC_LGUI,KC_LALT,          KC_SPC,                                        KC_RALT,  KC_RGUI, MO(_FL),  KC_RCTL),

  /* Keymap _FL: Function Layer
   * ,-----------------------------------------------------------.
   * |   |   |   |   |   |   |   |   |   |   |   |   |   |  RESET|
   * |-----------------------------------------------------------|
   * |     |   |   |   |   |   |   |   |   |   |   |BL-|BL+|BL   |
   * |-----------------------------------------------------------|
   * |      |   |   |   |   |   |   |       |   |   |   |        |
   * |-----------------------------------------------------------|
   * |        | F1|F2 | F3|F4 | F5| F6| F7| F8|   |   |          |
   * |-----------------------------------------------------------|
   * |    |    |    |                        |    |    |    |    |
   * `-----------------------------------------------------------'
   */
[_FL] = KEYMAP(
  #ifdef RGBLIGHT_ENABLE
  KC_GRV, KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, RESET, KC_TRNS,  \
  KC_TRNS,KC_TRNS,KC_TRNS,  KC_TRNS,KC_TRNS,KC_TRNS, KC_TRNS,KC_TRNS,KC_TRNS, KC_TRNS,   KC_TRNS,   BL_DEC,   BL_INC,   BL_TOGG, \
  KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS,              KC_TRNS, \
  KC_TRNS,RGB_TOG,RGB_MOD,RGB_HUI,RGB_HUD,RGB_SAI,RGB_SAD,RGB_VAI,RGB_VAD, KC_TRNS, KC_TRNS, KC_TRNS,  \
  KC_TRNS,KC_TRNS,KC_TRNS,          KC_TRNS,                               KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS),
  #else
  KC_GRV, KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, RESET, KC_TRNS,  \
  KC_TRNS,KC_TRNS,KC_TRNS,  KC_TRNS,KC_TRNS,KC_TRNS, KC_TRNS,KC_TRNS,KC_TRNS, KC_TRNS,   KC_TRNS,   BL_DEC,   BL_INC,   BL_TOGG, \
  KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS,KC_TRNS, KC_TRNS, KC_TRNS,    KC_TRNS,              KC_TRNS, \
  KC_TRNS, KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS,  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,  \
  KC_TRNS,KC_TRNS,KC_TRNS,          KC_TRNS,                               KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS),
  #endif
};

enum function_id {
    SHIFT_ESC,
};

const uint16_t PROGMEM fn_actions[] = {
  [0]  = ACTION_FUNCTION(SHIFT_ESC),
};

void action_function(keyrecord_t *record, uint8_t id, uint8_t opt) {
  static uint8_t shift_esc_shift_mask;
  switch (id) {
    case SHIFT_ESC:
      shift_esc_shift_mask = get_mods()&MODS_CTRL_MASK;
      if (record->event.pressed) {
        if (shift_esc_shift_mask) {
          add_key(KC_GRV);
          send_keyboard_report();
        } else {
          add_key(KC_ESC);
          send_keyboard_report();
        }
      } else {
        if (shift_esc_shift_mask) {
          del_key(KC_GRV);
          send_keyboard_report();
        } else {
          del_key(KC_ESC);
          send_keyboard_report();
        }
      }
      break;
  }
}

Step 6: Now compile your firmware with

make custom

Step 7: Next, using dfu-programmer erase the current firmware like so:

dfu-programmer atmega32u4 erase

Step 8: Now flash your custom firmware

dfu-programmer atmega32u4 flash S60RGB_custom.hex

Unplug and replug the board and that should be it!