Add temperature and break countdown display

metronom.ino

@@ -1,5 +1,6 @@
 #include "SAMDTimerInterrupt.h"
 #include "SAMD_ISR_Timer.h"
+#include "grove_alphanumeric_display.h"
 
 #define HW_TIMER_INTERVAL_MS 10
 SAMDTimer ITimer(TIMER_TC3);
@@ -7,7 +8,9 @@ SAMD_ISR_Timer ISR_Timer;
 
 void TimerHandler(void) { ISR_Timer.run(); }
 
-const int COUNTDOWN = 300;
+Seeed_Digital_Tube tube;
+
+const int COUNTDOWN = 240;
 const int PERIOD_MS = 1000;
 
 const uint BUTTON_PIN = 6;
@@ -20,15 +23,25 @@ const uint BUZZER_PIN = 0;
  *  >0 - COUNTDOWN
  */
 volatile int countdown = -1;
+volatile float temperature = 0.0;
 
 void setup() {
   initButton();
+  initTemperature();
+
+  // Wire initialized by temperature sensor
+  tube.setTubeType(TYPE_4, TYPE_4_DEFAULT_I2C_ADDR);
+  tube.setBrightness(15);
+  tube.setBlinkRate(BLINK_OFF);
+  tube.setPoint(true,true);
 
   ITimer.attachInterruptInterval_MS(10, TimerHandler);
-  ISR_Timer.setInterval(PERIOD_MS, metronomeRun);
+  ISR_Timer.setInterval(PERIOD_MS, runMetronome);
+  ISR_Timer.setInterval(PERIOD_MS, readTemperature);
+  ISR_Timer.setInterval(PERIOD_MS, updateTube);
 }
 
-void metronomeRun() {
+void runMetronome() {
   if (countdown > 0) {
     countdown -= 1;
 
@@ -38,4 +51,15 @@ void metronomeRun() {
   }
 }
 
+void updateTube() {
+  char tube_str[5];
+
+  if (countdown <= 0)
+    sprintf(tube_str, "%4u", (unsigned int) (temperature * 100.0));
+  else
+    sprintf(tube_str, "%4u", countdown);
+
+  tube.displayString(tube_str);
+}
+
 void loop() {}

temperature.ino

@@ -0,0 +1,12 @@
+#include "Seeed_BME280.h"
+
+BME280 sensor;
+
+void initTemperature() {
+  sensor.init();
+}
+
+void readTemperature() {
+  // TODO: add hysteresis
+  temperature = sensor.getTemperature();
+}