Lights Outs

Code

int redLedPin = D0;
int greenLedPin = D1;
int blueLedPin = D2;

int redButtonPin = D3;
int greenButtonPin = D4;
int blueButtonPin = D5;

int switchPowerPin = D7;
int switchPin = D8;

char *send_arr;
char *receive_arr;
int send_arr_count;


#define ARR_LENGTH 9

void setup() {
    pinMode(redLedPin, OUTPUT);
    pinMode(greenLedPin, OUTPUT);
    pinMode(blueLedPin, OUTPUT);
    pinMode(switchPowerPin, OUTPUT);
    
    digitalWrite(switchPowerPin, HIGH);
    
    pinMode(redButtonPin, INPUT_PULLUP);
    pinMode(greenButtonPin, INPUT_PULLUP);
    pinMode(blueButtonPin, INPUT_PULLUP);
    pinMode(switchPin, INPUT_PULLDOWN);
    
    
    Time.zone(-4);//set to est

    send_arr = (char*) calloc(ARR_LENGTH+1, sizeof(char));
    receive_arr = (char*) calloc(ARR_LENGTH+1, sizeof(char));
    send_arr_count = 0;
    
    setupReceiver();
    
    Serial.begin(9600);
}

void setupReceiver() {
    Particle.subscribe("button-presses", buttonPresses, MY_DEVICES);
}

void loop() {
    if (isButtonPressed(switchPin)) {
        loopReceiver();
    } else {
        loopSender();
    }
}

void loopReceiver() {
   send_arr_count = 0;
   char but = 0;
   int on_time = 200;
   int off_time = 100;
   
   delay(1000);
   for(int i = 0; i < ARR_LENGTH; i++) {
        if (receive_arr[i] == '0') {
            digitalWrite(redLedPin, HIGH);
            delay(on_time);
            digitalWrite(redLedPin, LOW);
            delay(off_time);
        } else if (receive_arr[i] == '1') {
            digitalWrite(greenLedPin, HIGH);
            delay(on_time);
            digitalWrite(greenLedPin, LOW);
            delay(off_time);
        } if (receive_arr[i] == '2') {
            digitalWrite(blueLedPin, HIGH);
            delay(on_time);
            digitalWrite(blueLedPin, LOW);
            delay(off_time);
        }
   }
}

void buttonPresses(const char *event, const char *data) {
    for(int i =0; i < ARR_LENGTH; i++) {
        receive_arr[i] = data[i];//copy into our array
    }
}

bool isButtonPressed(int pin) {
    int digitalValue = digitalRead(pin);
    //Serial.printf("Pin %d has value %d\n", pin, digitalValue);
    return digitalValue == LOW;
}

void loopSender() {
    if(isButtonPressed(redButtonPin)) {
        digitalWriteFast(redLedPin, HIGH);
        if (send_arr_count == 0 || send_arr[send_arr_count-1] != '0') {
            send_arr[send_arr_count++] = '0';
        }
        //digitalWrite(greenLedPin, LOW);
        //digitalWrite(blueLedPin, LOW);
    } else if(isButtonPressed(greenButtonPin)) {
        //digitalWrite(redLedPin, LOW);
        if (send_arr_count == 0 || send_arr[send_arr_count-1] != '1') {
            send_arr[send_arr_count++] = '1';
        }
        digitalWriteFast(greenLedPin, HIGH);
        //digitalWrite(blueLedPin, LOW);
    } else if(isButtonPressed(blueButtonPin)) {
        //digitalWrite(redLedPin, LOW);
        if (send_arr_count == 0 || send_arr[send_arr_count-1] != '2') {
            send_arr[send_arr_count++] = '2';
        }
        //digitalWrite(greenLedPin, LOW);
        digitalWriteFast(blueLedPin, HIGH);
    } else {
        digitalWriteFast(redLedPin, LOW);
        digitalWriteFast(greenLedPin, LOW);
        digitalWriteFast(blueLedPin, LOW);
    }

   if(send_arr_count == ARR_LENGTH) {
       send_arr[ARR_LENGTH] = '\0';
       Particle.publish("button-presses", send_arr, PRIVATE);
       send_arr_count = 0;
   }
}

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Conceptual Design

A scenario for this product is that a travelling business women might want to interact with her kid from far away. With this device, she can send button presses that the child would see and associate with her presence. The kid could also send button presses by flipping the switch to send mode.

Parts

Two Particle Argon

8 leds

6 buttons

2 switches

20 wires

Process

We initially spent most of our time figuring out how to get button presses to light up an LED and read that the button is pressed in the code. We had to experiment with different wiring solutions since we first had the button complete the circuit with the wire. We changed this to have the particle supply the led with power, and we also had to use pull down functionality to light up the led.
After this, we began to work on the networking components. We chose to use a string as our data format. After 9 button presses, the sender device will send the string over the network to the other device. Each character of the string encodes a button press. When the other device receives this string, it will iterate through the characters and light up the appropriate light.
We finally implemented the switch functionality, so that we could switch the devices on the fly from sender to receiver and vice versa.