init

README.md

@@ -1,3 +1,10 @@
 # temperaturedimmer
 
-AC Light Dimmer with DS18B20 temperature sensor
+AC Light Dimmer Module with DS18B20 temperature sensor changes gradually
+changing of AC power (useful for infrared ceramic heating bulbs). Note
+maxtemp and mintemp variables, in this range, the dimmer is working at
+partially power gradient-like. Reads temperature every minute, changes
+of dimming - 3 times per minute.
+
+
+![temperaturedimmer](https://dev.ussr.win/microcontrollers/temperaturedimmer/raw/branch/master/temperaturedimmer_bb.jpg)

temperaturedimmer.ino

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+// temperaturedimmer : AC Light Dimmer Module with DS18B20 temperature sensor changes gradually changing
+// of AC power (useful for infrared ceramic heating bulbs). Note maxtemp and mintemp variables, in this
+// range, the dimmer is working at partially power gradient-like. Reads temperature every minute, changes
+// of dimming - 3 times per minute.
+#include <OneWire.h>
+#include <DallasTemperature.h>
+#include <Thread.h>
+#define ONE_WIRE_BUS 6               // Temperature senson DS18B20 signal pin
+OneWire oneWire(ONE_WIRE_BUS);
+DallasTemperature sensors(&oneWire);
+bool serialshow = true;              // Enable/disable serial output
+int currenttemp = -127;              // -127 - means sensor can't gain temperature data
+int dimmerpin = 10;                  // Dimmer Digital PWM pin
+int dimming = 128;                   // Dimming level (0-128)  0 = FULL ON, 128 = OFF
+                                     // 4-128 is recommended range (4 is maximum)
+int maxtemp = 24;                    // Maximum temperature - dimmer works at minimum power
+                                     // if above maxtemp, dimmer not working
+int mintemp = 21;                    // Minumum temperature (or less) - dimmer works at maximum power
+// Threads:
+Thread checkTempThread = Thread();   // Thread for temperature state checking
+Thread changeDimmerThread = Thread(); // Thread for dimmer level changing
+
+void setup() {
+  if (serialshow) {
+    Serial.begin(9600);              // Initializes the Serial connection @ 9600 baud for debug
+    Serial.println("start");
+  }
+  pinMode(LED_BUILTIN, OUTPUT);      // Initializes builtin LED
+  digitalWrite(LED_BUILTIN, HIGH);
+  pinMode(dimmerpin, OUTPUT);        // Set the AC Load as output
+  attachInterrupt(0, zero_cross_int, RISING); // Choose the zero cross interrupt # from the table above
+  sensors.begin();
+  // Warning! zero_cross_int with sensors changes internal time,
+  // so digital 1000ms ~ physical 7100ms on Arduino Uno
+  checkTempThread.onRun(checkTemp);
+  checkTempThread.setInterval(8450); // Interval for checking temperature ~60sec
+  changeDimmerThread.onRun(changeDimmer);
+  changeDimmerThread.setInterval(2800); // Interval for change dimmer state ~20sec
+  checkTemp();
+}
+
+// zero_cross_int function from http://electronics.stackexchange.com/q/59615
+// the interrupt function must take no parameters and return nothing
+void zero_cross_int() {              // function to be fired at the zero crossing to dim the light
+  // Firing angle calculation : 1 full 50Hz wave =1/50=20ms
+  // Every zerocrossing thus: (50Hz)-> 10ms (1/2 Cycle)
+  // For 60Hz => 8.33ms (10.000/120)
+  // 10ms=10000us
+  // (10000us - 10us) / 128 = 75 (Approx) For 60Hz =>65
+  int dimtime = (75*dimming);        // For 60Hz =>65
+  delayMicroseconds(dimtime);        // Wait till firing the TRIAC
+  digitalWrite(dimmerpin, HIGH);     // Fire the TRIAC
+  delayMicroseconds(10);             // triac On propogation delay (for 60Hz use 8.33)
+  digitalWrite(dimmerpin, LOW);      // No longer trigger the TRIAC (the next zero crossing will swith it off) TRIAC
+}
+
+void loop() {
+  digitalWrite(LED_BUILTIN, LOW);
+  // Threads init:
+  if (checkTempThread.shouldRun())
+    checkTempThread.run();
+  if (changeDimmerThread.shouldRun())
+    changeDimmerThread.run();
+}
+
+void checkTemp() {
+  sensors.requestTemperatures();
+  currenttemp = int(sensors.getTempCByIndex(0));
+  if (serialshow) {
+    long currentTime = millis();
+    String tempString = currentTime + String(" temp: ")+ currenttemp;
+    Serial.println(tempString);
+  }
+}
+
+void changeDimmer() {
+  if (currenttemp != -127) {
+    if (currenttemp <= mintemp)
+      if (dimming > 4) dimming = dimming - 1;
+    if (currenttemp > maxtemp)
+      if (dimming < 128) dimming = dimming + 1;
+    if ((mintemp < currenttemp) and (currenttemp <= maxtemp)) {
+      int dimlevel = (124 / (maxtemp - mintemp)) * (currenttemp - mintemp);
+      if (dimming < dimlevel)
+        dimming = dimming + 1;
+      if (dimming > dimlevel)
+        dimming = dimming - 1;
+    }
+  } else {
+    if (dimming < 128) dimming = dimming + 1;
+    if (serialshow) {
+      long currentTime = millis();
+      String tempString = currentTime + String(" can't get temp data");
+      Serial.println(tempString);
+    }
+    // LED blinking is indication of temperature sensor failure
+    for (int i=1; i <= 10; i++) {
+      digitalWrite(LED_BUILTIN, HIGH);
+      delay(10);
+      digitalWrite(LED_BUILTIN, LOW);
+      delay(20);
+    }
+  }
+}