jimoconnell · June 19, 2015 03:28 · Jun 19, 2015
diff --git a/gistfile1.ino b/gistfile1.ino
@@ -0,0 +1,55 @@
+// Copied from:
+// http://www.instructables.com/id/Interface-a-rotary-phone-dial-to-an-Arduino/?ALLSTEPS
+// By Instructables user guidomax
+int needToPrint = 0;
+int count;
+int in = 2;
+int lastState = LOW;
+int trueState = LOW;
+long lastStateChangeTime = 0;
+int cleared = 0;
+
+// constants
+
+int dialHasFinishedRotatingAfterMs = 100;
+int debounceDelay = 10;
+
+void setup()
+{
+Serial.begin(9600);
+pinMode(in, INPUT);
+}
+
+void loop()
+{
+int reading = digitalRead(in);
+
+if ((millis() - lastStateChangeTime) > dialHasFinishedRotatingAfterMs) {
+// the dial isn't being dialed, or has just finished being dialed.
+if (needToPrint) {
+// if it's only just finished being dialed, we need to send the number down the serial
+// line and reset the count. We mod the count by 10 because '0' will send 10 pulses.
+Serial.print(count % 10, DEC);
+needToPrint = 0;
+count = 0;
+cleared = 0;
+}
+} 
+
+if (reading != lastState) {
+lastStateChangeTime = millis();
+}
+if ((millis() - lastStateChangeTime) > debounceDelay) {
+// debounce - this happens once it's stablized
+if (reading != trueState) {
+// this means that the switch has either just gone from closed->open or vice versa.
+trueState = reading;
+if (trueState == HIGH) {
+// increment the count of pulses if it's gone high.
+count++; 
+needToPrint = 1; // we'll need to print this number (once the dial has finished rotating)
+} 
+}
+}
+lastState = reading;
+}