First upload of local code.

.gitignore

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+
+*.pdf

D1L_firmware1/D1L_firmware1.ino

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+/*
+    Eberspacher D1L Controller Firmware
+
+    Arthur Hazleden
+    December 2016
+
+    D10 - standby LED
+    D11 - startup LED
+    D12 - running LED
+    D13 - shutdown LED
+
+    D3 - flame switch sensor
+    D4 - overtemperature switch sensor
+    D5 - thermostat switch
+
+    D6 - glow plug relay, on open collector NPN
+    D - extra open collector NPN
+    D8 - fuel pump mosfet
+    D9 - blower motor PWM control mosfet
+
+    A0 - battery voltage across a 22k / 10k resistor divider network
+    A1 - cabin temperature from and LM
+*/
+
+
+// pin assignments
+const int flameSwitch = 3;
+const int overTempSwitch = 4;
+const int tStatSwitch = 5;
+
+const int glowRelay = 6;
+//const int spareOC = 7;
+const int fuelPump = 8;
+const int blowerMotor = 9;
+
+
+// variables used for timing
+unsigned long previousMillis = 0;
+
+//variables used for heater control
+int pumpRate = 0;
+int heaterState = 0;
+
+int tStatState = 0;
+int lastTStatState = 0;
+unsigned long lastDebounceTime = 0;
+unsigned long debounceDelay = 200;
+int callForHeat = 0;  //set to 1 when the thermostat indicates heating is needed
+
+unsigned long previousPumpMillis = 0;
+
+// constants defining heater startup function timing, times are when these operations start after the thermostat engauges the heater
+const long justGlow = 500; // engauge the glowplug
+const long blowerStartup = 3000;  //start the blower on low speed
+const long startupFueling = 60000;  //start with pump at low rate
+const long glowCut = 60000; //cut glow after flame detected and this time
+const long powerIncrease = 100000; //blower and pump to medium speed at this point, warm up heater housing in prep for run mode
+const long fullPower = 260000; //blower and pump to full speed at this point, switch to run mode after this
+
+// constants defining heater shutdown function timing, times are when these operations start after the thermostat stops the heater
+const long blowerHigh = 20000; //cut fuel, engauge glowplug for cleaning and start cooling down the heater
+const long glowCleaning = 40000; //disengauge glow plug, is clean by now
+const long blowerLow = 240000;  //stop blower after the cooldown phase, proceed to standby phase
+
+
+//constants defining heater function rates (all in milliseconds, a shorter time means more pumps per second)
+const int pumpPulseTime = 100;
+const int lowFuelRate = 600;
+const int mediumFuelRate = 400;
+const int highFuelRate = 250;
+
+
+void setup() {
+
+  for (int thisPin = 3; thisPin <= 5; thisPin++) {
+    pinMode(thisPin, INPUT);
+  }
+
+  for (int thisPin = 6; thisPin <= 9; thisPin++) {
+    pinMode(thisPin, OUTPUT);
+  }
+  digitalWrite(glowRelay, LOW);
+  digitalWrite(spareOC, LOW);
+  digitalWrite(fuelPump, LOW);
+  digitalWrite(blowerMotor, LOW);
+
+}
+
+void loop() {
+
+  thermostat(); //check the temperature and state, change state if necessary
+
+  pump(); //update the super slow fuel pump PWM
+
+  /* Heater States:
+     0 - standby
+     1 - startup
+     2 - running
+     3 - shutdown
+  */
+  unsigned long currentMillis = millis();
+
+  switch (heaterState) {
+    case 0: // ********** standby **********
+      digitalWrite(glowRelay, LOW);
+      digitalWrite(spareOC, LOW);
+      digitalWrite(blowerMotor, LOW);
+
+      pumpRate = 0;
+
+      break;
+
+    case 1: // ********** startup **********
+
+      if (currentMillis - previousMillis < justGlow) {  // engauge the glowplug
+        digitalWrite(glowRelay, HIGH);
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis < blowerStartup) { //start the blower on low speed
+        analogWrite(blowerMotor, 50);
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis < startupFueling) {  //start with pump at low rate
+        pumpRate = lowFuelRate;
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis < glowCut) { //cut glow after flame detected and this time
+        digitalWrite(glowRelay, LOW);
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis < powerIncrease) { //blower and pump to medium speed at this point, warm up heater housing in prep for run mode
+        analogWrite(blowerMotor, 150);
+        pumpRate = mediumFuelRate;
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis < fullPower) { //blower and pump to full speed at this point, switch to run mode after this
+        analogWrite(blowerMotor, 255);
+        pumpRate = highFuelRate;
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis >= fullPower) {  //advance to run phase
+        heaterState = 2;
+        previousMillis = currentMillis;
+      }
+
+
+      break;
+
+    case 2: // ********** running **********
+      //in future, add multiple power levels for PI control? avoid the glow plug current draw on startup!
+
+      break;
+
+    case 3: // ********** shutdown **********
+
+      if (currentMillis - previousMillis < blowerHigh) {  //cut fuel, engauge glowplug for cleaning and start cooling down the heater
+        analogWrite(blowerMotor, 255);
+        pumpRate = 0;
+        digitalWrite(glowRelay, HIGH);
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis < glowCleaning) {  //disengauge glow plug, is clean by now
+        digitalWrite(glowRelay, LOW);
+        previousMillis = currentMillis;
+      }
+
+      if (currentMillis - previousMillis >= blowerLow) {  //stop blower after the cooldown phase, proceed to standby phase
+        analogWrite(blowerMotor, 0);
+        heaterState = 0;
+        previousMillis = currentMillis;
+      }
+
+      break;
+
+  }
+}
+
+
+
+void thermostat() { //updates thermostat reading, checks for overtemperature condition, changes heater state
+
+  // ********** Debounced thermostat checkup: **********
+  int reading = digitalRead(tStatSwitch);
+  // If the switch changed, due to noise or pressing:
+  if (reading != lastTStatState) {
+    // reset the debouncing timer
+    lastDebounceTime = millis();
+  }
+  if ((millis() - lastDebounceTime) > debounceDelay) {
+    // whatever the tStatState is at, it's been there for longer
+    // than the debounce delay, so take it as the actual current state:
+
+    // if the button state has changed:
+    if (reading != tStatState) {
+      tStatState = reading;
+
+      // only toggle the call for heat if the new tstat state is HIGH
+      if (tStatState == HIGH) {
+        callForHeat = !callForHeat;
+      }
+    }
+  }
+  // save the tStatState.  Next time through the loop,
+  // it'll be the lastTStatState:
+  lastTStatState = reading;
+
+  // ********** Heater state change: **********
+  if (callForHeat == 1 && heaterState == 0) { //if tstat says low temp and the heater is idle, start it up
+    heaterState = 1;
+  }
+
+  if (callForHeat == 0 && heaterState == 2) { //if tstat says high temp and heater is running, shut it down
+    heaterState = 3;
+  }
+
+
+  // ********** Overtemperature switch checkup: **********
+  if (overTempSwitch == 1) {
+    heaterState = 3;
+  }
+
+}
+
+void pump() { //based on the setting of the pump, adjust the time between pulses, pulse time is 100ms
+
+  unsigned long currentMillis = millis();
+
+  if (currentMillis - previousPumpMillis >= pumpPulseTime) {
+    digitalWrite(fuelPump, LOW);
+  }
+
+  if (currentMillis - previousPumpMillis >= pumpRate) {
+    previousPumpMillis = currentMillis;
+    digitalWrite(fuelPump, HIGH);
+  }
+
+}
+