Update countdown

Do not refresh display if value not changed

bme280.ino

@@ -0,0 +1,23 @@
+#include "Seeed_BME280.h"
+
+BME280 sensor;
+float highTemp = 0.0, lowTemp = 0.0;
+const float blindZone = 0.03;
+
+void initBME280() {
+  sensor.init();
+}
+
+void readTemperature() {
+  float newTemperature = sensor.getTemperature();
+
+  if (newTemperature > highTemp) {
+    temperature = newTemperature;
+    highTemp = newTemperature;
+    lowTemp = highTemp - blindZone;
+  } else if (newTemperature < lowTemp) {
+    temperature = newTemperature;
+    lowTemp = newTemperature;
+    highTemp = lowTemp + blindZone;
+  };
+}

button.ino

@@ -1,5 +1,7 @@
 volatile unsigned long lastButtonPress = millis();
 
+// Debouncing na timerze:
+// https://github.com/khoih-prog/TimerInterrupt/blob/master/examples/SwitchDebounce/SwitchDebounce.ino
 void initButton() {
   pinMode(BUTTON_PIN, INPUT_PULLUP);
   // Order of ISRs matter: RISING should be invoked first
@@ -10,12 +12,15 @@ void initButton() {
 void buttonISRstate() {
   if ((millis() - lastButtonPress) > 100) {
     if (countdown < 0)
+      // TODO: enable metronome timer
       countdown = 0;
     else if (countdown == 0)
+      // TODO: restart metronome timer to align countdown
       countdown = COUNTDOWN;
     else {
       countdown = -1;
       digitalWrite(BUTTON_LED_PIN, LOW);
+      // TODO: disable metronome timer
     }
   }
 }

buzzer.ino

@@ -0,0 +1,22 @@
+SAMDTimer BuzzerTimer(TIMER_TC5);
+
+bool attached = false;
+
+void initBuzzer() {
+  pinMode(BUZZER_PIN, OUTPUT);
+}
+
+void buzzerISR() {
+  digitalWrite(BUZZER_PIN, !digitalRead(BUZZER_PIN));
+}
+
+void buzz() {
+  if (attached)
+    BuzzerTimer.enableTimer();
+  else
+    BuzzerTimer.attachInterrupt(BUZZER_FREQ *2, buzzerISR);
+}
+
+void noBuzz() {
+  BuzzerTimer.disableTimer();
+}

metronom.ino

@@ -1,14 +1,15 @@
 #include "SAMDTimerInterrupt.h"
 #include "SAMD_ISR_Timer.h"
 
-#define HW_TIMER_INTERVAL_MS 10
+SAMDTimer TaskTimer(TIMER_TC3);
-SAMDTimer ITimer(TIMER_TC3);
+SAMD_ISR_Timer TasksISRs;
-SAMD_ISR_Timer ISR_Timer;
 
-void TimerHandler(void) { ISR_Timer.run(); }
+void TasksHandler(void) { TasksISRs.run(); }
 
-const int COUNTDOWN = 300;
+
+const int COUNTDOWN = 600;
 const int PERIOD_MS = 1000;
+const int BUZZER_FREQ = 300;
 
 const uint BUTTON_PIN = 6;
 const uint BUTTON_LED_PIN = 5;
@@ -20,26 +21,30 @@ const uint BUZZER_PIN = 0;
  *  >0 - COUNTDOWN
  */
 volatile int countdown = -1;
+volatile float temperature = 0.0;
 
 void setup() {
   initButton();
+  initBME280();
+  initBuzzer();
+  initTube();
 
-  ITimer.attachInterruptInterval_MS(10, TimerHandler);
+  TaskTimer.attachInterruptInterval_MS(20, TasksHandler);
-  ISR_Timer.setInterval(PERIOD_MS, metronomeBeat);
+  TasksISRs.setInterval(PERIOD_MS, runMetronome);
-  ISR_Timer.setInterval(PERIOD_MS, metronomeCountdown);
+  TasksISRs.setInterval(PERIOD_MS, readTemperature);
+  // TODO: move display from ISR to loop()
+  TasksISRs.setInterval(200, updateTube);
 }
 
-void metronomeCountdown() {
+void runMetronome() {
   if (countdown > 0) {
     countdown -= 1;
 
     digitalWrite(BUTTON_LED_PIN, countdown % 2 ? HIGH : LOW);
+  } else if (countdown == 0) {
+    TasksISRs.setTimeout(100, noBuzz);
+    buzz();
   }
 }
 
-void metronomeBeat() {
-  if (countdown == 0)
-    tone(BUZZER_PIN, 1000, 100);
-}
-
 void loop() {}

tube.ino

@@ -0,0 +1,30 @@
+#include "grove_alphanumeric_display.h"
+
+Seeed_Digital_Tube tube;
+char tubeText[5] = "";
+
+void initTube() {
+  // Wire initialized by BME280 sensor
+  tube.setTubeType(TYPE_4, TYPE_4_DEFAULT_I2C_ADDR);
+  tube.setBrightness(15);
+  tube.setBlinkRate(BLINK_OFF);
+}
+
+void updateTube() {
+  char newText[5];
+  bool highPoint = false, lowPoint = false;
+
+  if (countdown <= 0) {
+    sprintf(newText, "%4u", (unsigned int) (temperature * 100.0));
+    lowPoint = true;
+  } else {
+    sprintf(newText, "%4u", countdown);
+  }
+
+  if (strcmp(tubeText, newText)) {
+    strcpy(tubeText, newText);
+    tube.displayString(tubeText);
+    tube.setPoint(highPoint, lowPoint);
+    tube.display();
+  }
+}