repeating Fn key: press twice quickly to repeat.

layer.c

@@ -43,6 +43,11 @@
  *     Fn key send      ___|~~~~~~~~~|_____________
  *     other key press  ~~~~~~~|___________________
  *     other key send   ~~~~~~~|___________________
+ *
+ * 6. press Fn twice quickly and keep holding down.(repeat)
+ *     Layer sw         ___________________________
+ *     Fn key press     ___|~|____|~~~~~~~~~~~~~~~~
+ *     Fn key send      _____|~|__|~~~~~~~~~~~~~~~~
  */
 
 // LAYER_ENTER_DELAY: prevent from moving new layer
@@ -70,17 +75,17 @@ void layer_switching(uint8_t fn_bits)
 {
     // layer switching
     static uint8_t new_layer = 0;
-    static uint8_t last_bits = 0;
+    static uint8_t last_fn = 0;
     static uint8_t last_mods = 0;
     static uint16_t last_timer = 0; 
+    static uint8_t sent_fn = 0;
 
-    if (fn_bits == last_bits) { // Fn key is not changed
+    if (fn_bits == last_fn) { // Fn key is not changed
         if (current_layer != new_layer) {
             // not switch layer yet
             if (timer_elapsed(last_timer) > LAYER_ENTER_DELAY) {
                 debug("Fn case: 1,2,3(switch layer)\n");
                 // case: 1,2,3
-                // switch layer after LAYER_ENTER_DELAY elapse
                 current_layer = new_layer;
                 debug("timer_elapsed: "); debug_hex16(timer_elapsed(last_timer)); debug("\n"); 
                 debug("switch layer: "); debug_hex(current_layer); debug("\n");
@@ -90,55 +95,58 @@ void layer_switching(uint8_t fn_bits)
                 // send only Fn key first
                 usb_keyboard_swap_report();
                 usb_keyboard_clear_report();
-                usb_keyboard_add_code(keymap_fn_keycode(last_bits));
+                usb_keyboard_add_code(keymap_fn_keycode(last_fn));
                 usb_keyboard_set_mods(last_mods);
                 usb_keyboard_send();
                 usb_keyboard_swap_report();
                 // add Fn key to send with other keys
-                usb_keyboard_add_code(keymap_fn_keycode(last_bits));
-                // cancel layer switching 
+                usb_keyboard_add_code(keymap_fn_keycode(last_fn));
+
                 new_layer = 0;
+                sent_fn = last_fn;
            }
         } else {
             if (fn_bits && new_layer == 0) {
-                // case: 4,5
-                // send Fn key
-                usb_keyboard_add_code(keymap_fn_keycode(last_bits));
+                // case: 4,5,6
+                usb_keyboard_add_code(keymap_fn_keycode(last_fn));
+                sent_fn = last_fn;
             }
         }
     } else { // Fn key is changed
         if (fn_bits == 0) { // Fn key is released(falling edge)
             if (!layer_used && timer_elapsed(last_timer) < LAYER_SEND_FN_TERM) {
                 debug("Fn case: 2(send Fn)\n");
-                // send Fn key (case: 2[no layer used],3)
+                // case: 2
                 usb_keyboard_swap_report();
                 usb_keyboard_clear_report();
-                usb_keyboard_add_code(keymap_fn_keycode(last_bits));
+                usb_keyboard_add_code(keymap_fn_keycode(last_fn));
                 usb_keyboard_set_mods(last_mods);
                 usb_keyboard_send();
                 usb_keyboard_swap_report();
+                sent_fn = last_fn;
             }
-            debug("Fn case: 1,2,3,4,5(return to default layer)\n");
-            // return to default layer(case: 1,2,3,4,5)
+            debug("Fn case: 1,2,3,4,5,6(return to default layer)\n");
             new_layer = 0;
             current_layer = 0;
         } else { // Fn Key is pressed(rising edge)
-            if (!usb_keyboard_has_key()) {
+            if (usb_keyboard_has_key() ||
+                    (fn_bits == sent_fn &&timer_elapsed(last_timer) < LAYER_ENTER_DELAY)) {
+                debug("Fn case: 5,6(add Fn to repeat)\n");
+                usb_keyboard_add_code(keymap_fn_keycode(fn_bits));
+                sent_fn = fn_bits;
+            } else {
                 debug("Fn case: 1,2,3,4(ready for switching layer)\n");
                 // ready for switching layer(case: 1,2,3,4)
                 new_layer = keymap_fn_layer(fn_bits);
-            } else {
-                debug("Fn case: 5(add Fn to report)\n");
-                // add Fn key to send with other keys(case: 5)
-                usb_keyboard_add_code(keymap_fn_keycode(fn_bits));
+                sent_fn = 0;
             }
         }
         layer_used = false;
-        last_bits = fn_bits;
+        last_fn = fn_bits;
         last_mods = usb_keyboard_mods;
         last_timer = timer_read();
         debug("new_layer: "); debug_hex(new_layer); debug("\n");
-        debug("last_bits: "); debug_bin(last_bits); debug("\n");
+        debug("last_fn: "); debug_bin(last_fn); debug("\n");
         debug("last_mods: "); debug_hex(last_mods); debug("\n");
         debug("last_timer: "); debug_hex16(last_timer); debug("\n");
     }