waver_firmware_1.c

int sPin = A5; // Pin for the servo signal input
int buttonPin = D0; // Pin for the button input
Servo serv; // Instance of Servo object; takes care of low-level servo communication

void setup() {
    serv.attach(sPin); // Tells the Servo object which pin the servo is connected to
    
    // Allows us to use the button pin for input.
    // Read about "pull up" resistors here: http://playground.arduino.cc/CommonTopics/PullUpDownResistor
    pinMode(buttonPin, INPUT_PULLUP);
    
    // Subscribe to other Photon's events: call wave function whenever other Photon
    // publishes an event.
    Particle.subscribe("wave_0000000002", wave);
}

// this function loops as long as the Photon is on.
void loop() {
    
    // store current reading of button pin
    int bState = digitalRead(buttonPin);
    
    // If it's "LOW", we publish a wave event, so the other Photon will "wave".
    // Note that we are interested in when it is LOW, and not HIGH, because
    // of the notion of the "pull up" resistor.
    if (bState == LOW) { 
        // Publish event for other photon.
        Particle.publish("wave_0000000001", "on");
        delay(3700); // Let the other Photon finish its sweep before we publish another wave.
        // This is not particularly elegant. If the internet connection is weak, this could
        // cause a new wave to be triggered in the middle of an old one, causing erratic 
        // waving behaviour.
    }
}

// Perform a full sweep of the "wave".
// Variable j determines how many sweeps to perform in one wave.
// Modify the values inside the parantheses following the two "delay"s to adjust the wave speed.
// Modify the value i to adjust which angle to perform the sweep to.
void wave(const char *event, const char *data) {
    for (int j = 0; j < 2; j++) {
        for (int i = 0; i < 180; i++) {
            serv.write(i);
            delay(5);
        }
        for (int i = 180; i > 0; i-=1) {
            serv.write(i);
            delay(5);
        }
    }
    
}