Some optimizations.

MIDI-Host-Adapter.ino

@@ -45,7 +45,6 @@ bool high_freq = false;
 TM1638plus_Model2 tm(STROBE_TM, CLOCK_TM, DIO_TM, swap_nibbles, high_freq);
 elapsedMillis button_debounce_timer;
 elapsedMillis blink_timer;
-elapsedMillis double_press_timer;
 uint8_t actual_channel;
 uint8_t new_channel;
 
@@ -89,31 +88,33 @@ void loop() {
 
   button = tm.ReadKey16();
 
-  if (button > 0 && button_debounce_timer > BUTTON_DEBOUNCE_TIME_MS && double_press_timer > BUTTON_DOUBLE_PRESS_MS) {
+  if (button > 0 && button != actual_channel && button_debounce_timer > BUTTON_DEBOUNCE_TIME_MS) {
+    if (button != new_channel) {
       // Button pressed once
       Serial.print("Button once: ");
       Serial.println(button, DEC);
       button_debounce_timer = 0;
-    double_press_timer = 0;
       blink_timer = 0;
       new_channel = button;
       tm.DisplayDecNumNibble(new_channel, actual_channel, 0, false, TMAlignTextRight);
-  } else if (button > 0 && button_debounce_timer > BUTTON_DEBOUNCE_TIME_MS && double_press_timer < BUTTON_DOUBLE_PRESS_MS && button == new_channel) {
+    } else {
       // Button pressed twice
       Serial.print("Button twice: ");
       Serial.println(button, DEC);
       actual_channel = new_channel;
       EEPROM.update(EEPROM_ADDRESS, 0xf0 | actual_channel);
       SetMidiChannel(actual_channel);
-  } else if (actual_channel != new_channel) {
+    }
+  }
+
+  if (actual_channel != new_channel) {
     if (blink_timer > BLINK_FREQUENCY_MS) {
       blink_timer = 0;
       tm.DisplayDecNum(actual_channel, 0, false, TMAlignTextRight);
     } else if (blink_timer > BLINK_FREQUENCY_MS / 2) {
       tm.DisplayDecNumNibble(new_channel, actual_channel, 0, false, TMAlignTextRight);
     }
-  } else
+  } else tm.DisplayDecNum(actual_channel, 0, false, TMAlignTextRight);
-    tm.DisplayDecNum(actual_channel, 0, false, TMAlignTextRight);
 }
 
 void SetMidiChannel(uint8_t channel) {