Display also humidity and pressure

Display update triggered by value change, not interval

button.ino

@@ -1,6 +1,6 @@
 volatile unsigned long lastButtonPress = millis();
 
-// Debouncing na timerze:
+// Debouncing using timer:
 // https://github.com/khoih-prog/TimerInterrupt/blob/master/examples/SwitchDebounce/SwitchDebounce.ino
 void initButton() {
   pinMode(BUTTON_PIN, INPUT_PULLUP);
@@ -9,17 +9,20 @@ void initButton() {
   attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), buttonISRstate, RISING);  
 }
 
+// FIXME: runMetronome ISR should be started/stopped by button. Otherwise fraction of first PERIOD_MS is lost from countdown.
 void buttonISRstate() {
   if ((millis() - lastButtonPress) > 100) {
     if (countdown < 0)
       // TODO: enable metronome timer
       countdown = 0;
-    else if (countdown == 0)
+    else if (countdown == 0) {
       // TODO: restart metronome timer to align countdown
       countdown = COUNTDOWN;
-    else {
+      updateTube();
+    } else {
       countdown = -1;
       digitalWrite(BUTTON_LED_PIN, LOW);
+      updateTube();
       // TODO: disable metronome timer
     }
   }