Display also humidity and pressure

Display update triggered by value change, not interval

README.md

@@ -0,0 +1,21 @@
+Arduino based device acting as:
+* metronome, for exercises that require timing,
+* countdown timer, for rest between exercises,
+* thermometer / hygrometer - when not uses for exercises.
+
+Part list:
+* Arduino MKR 1010 (ABX00023)
+* Arduino MKR Connector Carrier, Grove compatible (ASX00007)
+* BME280 sensor (Seeed Studio SEE-11355)
+* quad, alphanumeric (14-segment), HT16K33 based display (SeedStudio SEE-14733)
+* push button with backlight (Seeed Studio SEE-13660)
+* passive buzzer (Seeed Studio SEE-17268)
+* I2C 6 port hub (Seeed Studio SEE-15856)
+* cables - as required
+All modules based on Grove connections and cables.
+
+All modules are connected to Arduino through Connector Carrier:
+* buzzer - port D0,
+* button - port D5,
+* I2C hub - port TWI,
+* sensor and display - to hub (any port)

bme280.ino

@@ -0,0 +1,50 @@
+#include "Seeed_BME280.h"
+
+enum {
+  LOWER = 0,
+  HIGHER
+};
+
+BME280 sensor;
+float bounds[2][SENSORS] = {};
+const float hysteresisWidth[SENSORS] = {0.03, 0.5, 0.5};
+
+void initBME280() {
+  sensor.init();
+}
+
+void readSensors() {
+  float newValue;
+
+  for (uint i = 0; i < SENSORS; i++) {
+    switch (i) {
+      case TEMPERATURE:
+        newValue = sensor.getTemperature();
+        break;
+
+      case HUMIDITY:
+        newValue = sensor.getHumidity();
+        break;
+
+      case PRESSURE:
+        newValue = sensor.getPressure();
+        break;
+    }
+
+    if (newValue > bounds[HIGHER][i]) {
+      sensorValue[i] = newValue;
+      bounds[HIGHER][i] = newValue;
+      bounds[LOWER][i] = bounds[HIGHER][i] - hysteresisWidth[i];
+      if ((countdown <= 0) && (displaySensor == i)) {
+        displayNeedsUpdate = true;
+      }
+    } else if (newValue < bounds[LOWER][i]) {
+      sensorValue[i] = newValue;
+      bounds[LOWER][i] = newValue;
+      bounds[HIGHER][i] = bounds[LOWER][i] + hysteresisWidth[i];
+      if ((countdown <= 0) && (displaySensor == i)) {
+        displayNeedsUpdate = true;
+      }
+    };
+  };
+}

button.ino

@@ -1,5 +1,7 @@
 volatile unsigned long lastButtonPress = millis();
 
+// Debouncing using timer:
+// 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
@@ -7,15 +9,21 @@ 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
     }
   }
 }

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

@@ -1,45 +1,82 @@
 #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(); }
+enum {
+  TEMPERATURE = 0,
+  HUMIDITY,
+  PRESSURE,
+  SENSORS
+};
 
-const int COUNTDOWN = 300;
+// COUNTDOWN is effectively multiplied by METRONOME_INTERVAL
-const int PERIOD_MS = 1000;
+const int COUNTDOWN = 600;
+// INTERVALS and TIMESHARES given in [ms]
+const uint TASK_HANDLER_INTERVAL = 20;
+const uint METRONOME_INTERVAL = 1000;
+const uint SENSOR_INTERVAL = 1000;
+const uint SENSOR_TIMESHARE[SENSORS] = {90000, 20000, 10000};
+// FREQUENCY in [Hz]
+const uint BUZZER_FREQ = 300;
 
 const uint BUTTON_PIN = 6;
 const uint BUTTON_LED_PIN = 5;
 const uint BUZZER_PIN = 0;
 
 /* Metronome state is expressed by countdown:
- *  -1 - IDLE
+    -1 - IDLE
- *   0 - BEATING
+     0 - BEATING
- *  >0 - COUNTDOWN
+    >0 - COUNTDOWN
- */
+   Unless metronome is in COUNTDOWN mode, display rotates through sensor readings.
+*/
 volatile int countdown = -1;
+// Units: temperature [C], humidity [%], pressure [P]
+volatile float sensorValue[SENSORS] = {};
+volatile uint displaySensor = TEMPERATURE;
+volatile bool displayNeedsUpdate = false;
+volatile bool tubeRotated = false;
+int tubeTimerID;
+
+void TasksHandler(void) {
+  TasksISRs.run();
+
+  if (displayNeedsUpdate || tubeRotated)
+    updateTube();
+
+  if (tubeRotated) {
+    TasksISRs.changeInterval(tubeTimerID, SENSOR_TIMESHARE[displaySensor]);
+    tubeRotated = false;
+  }
+}
 
 void setup() {
   initButton();
+  initBME280();
+  initBuzzer();
+  initTube();
 
-  ITimer.attachInterruptInterval_MS(10, TimerHandler);
+  readSensors();
-  ISR_Timer.setInterval(PERIOD_MS, metronomeBeat);
+  updateTube();
-  ISR_Timer.setInterval(PERIOD_MS, metronomeCountdown);
+
+  TaskTimer.attachInterruptInterval_MS(TASK_HANDLER_INTERVAL, TasksHandler);
+  TasksISRs.setInterval(METRONOME_INTERVAL, runMetronome);
+  TasksISRs.setInterval(SENSOR_INTERVAL, readSensors);
+  tubeTimerID = TasksISRs.setInterval(SENSOR_TIMESHARE[displaySensor], rotateTube);
 }
 
-void metronomeCountdown() {
+void runMetronome() {
   if (countdown > 0) {
     countdown -= 1;
 
     digitalWrite(BUTTON_LED_PIN, countdown % 2 ? HIGH : LOW);
+
+    displayNeedsUpdate = true;
+  } 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 +1,51 @@
+#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 rotateTube() {
+  displaySensor = (displaySensor + 1) % SENSORS;
+  tubeRotated = true;
+}
+
+void updateTube() {
+  char newText[5];
+  bool highPoint = false, lowPoint = false;
+  uint value = countdown;
+
+  if (countdown <= 0) {
+    switch (displaySensor) {
+      case TEMPERATURE:
+        value = (uint) (sensorValue[TEMPERATURE] * 100);
+        lowPoint = true;
+        break;
+      case HUMIDITY:
+        // TODO: add % sign?
+        value = (uint) (sensorValue[HUMIDITY]);
+        break;
+      case PRESSURE:
+        value = (uint) (sensorValue[PRESSURE] / 100);
+        break;
+    }
+  }
+  sprintf(newText, "%4u", value);
+
+  // TODO: In the current mode of display refresh (displayNeedsUpdate) it should not be necessary to check previous text
+  // Maybe add LED switching for case when the strings match as a rough check before removing comparison?
+  // Or LED switching when display is updated?
+  if (strcmp(tubeText, newText)) {
+    strcpy(tubeText, newText);
+    tube.displayString(tubeText);
+    tube.setPoint(highPoint, lowPoint);
+    tube.display();
+  }
+
+  displayNeedsUpdate = false;
+}