A Magic Maker example project

lucerna-relay.cpp

/*
  Copyright (c) 2018 Seawisp Hunter, LLC

  Licensed under the MIT license.
*/

/*
  Lucerna Relay

  A Magic Maker[1] example project

  [1]: http://seawisphunter.com/products/magic-maker
*/

/************************************************/
const int relayPin = 13;//the number of the LED pin
int relayState = 0;
unsigned long timeOfStateChange = 0;
unsigned long timeOfStateChangeRequested = 0;
const unsigned long millisBetweenStateChange = 5000; // Don't change state faster than this.

/************************************************/
void setup() {
  pinMode(relayPin, OUTPUT); // Initialize the digital pin as an output.
  digitalWrite(relayPin, relayState);
  timeOfStateChange = millis();
  timeOfStateChangeRequested = timeOfStateChange;// - millisBetweenStateChange;
  Serial.begin(115200);
}

/************************************************/
// The loop routine runs over and over again forever.
void loop() {
  unsigned long t = millis();
  if (Serial.available() > 0) {
    String wholeInput = Serial.readString();
    int start = 0;
    int indexOfNewline;
    do {
      indexOfNewline = wholeInput.indexOf("\n", start);
      String input;
      if (indexOfNewline == -1) {
        input = wholeInput.substring(start);
      } else {
        input = wholeInput.substring(start, indexOfNewline + 1);
        start = indexOfNewline + 1;
      }
      input.trim();
      if (input.length() == 0)
        continue;

      Serial.println("LINE: '" + input + "'");
      if (input.startsWith("Lucerna")) {
        if (input.startsWith("Lucerna on")) {
          relayState = 1;
        } else if (input.startsWith("Lucerna off")) {
          relayState = 0;
        } else {
          relayState = !relayState;
        }
        if (t - timeOfStateChange > millisBetweenStateChange) {
          digitalWrite(relayPin, relayState);
          timeOfStateChange = t;
          Serial.println("Lucerna state change " + String(relayState ? "on" : "off"));
        } else {
          timeOfStateChangeRequested = t;
          Serial.println("Lucerna state change requested " + String(relayState ? "on" : "off"));
        }
      }
    } while (indexOfNewline != -1);
  }

  if (timeOfStateChangeRequested > timeOfStateChange
      && (t - timeOfStateChange) < millisBetweenStateChange) {
    digitalWrite(relayPin, relayState);
    timeOfStateChange = t;
    Serial.println("Lucerna delayed state change " + String(relayState ? "on" : "off"));
  }
}