BCH PL$ - A Retro Analog Bitcoin Cash Meter

// Mac McAlpine UNCC MEGR3171 Indroduction to Instrumentation
//example code for testing the milliamp gauge with PWM and DAC pins.
//dac seems to output up to 10ma
//pwm seems to output up to 25ma with 100 ohm
//pwm with 3K in series with the 1ma FS meter seems to be an accurate match.
//Modified to publish a webhook event and receive cryptocurrency prices.
//webhook is included at the end of this code in the comments.

int ledpin = D7;
int pwmpin = D1;

Timer cointimer(10000, cointimerfunction);

void setup() {
    Serial.begin(230400);
    pinMode(DAC1, OUTPUT);
    pinMode(pwmpin, OUTPUT);
    pinMode(ledpin, OUTPUT);
    Particle.function("setgauge",setdac);
    //Particle.subscribe("hook-response/bitcoin2", bitcoinHandler, MY_DEVICES);  // Subscribe to the webhook response
    Particle.subscribe("hook-response/bchpls", bitcoinHandler, MY_DEVICES);  // Subscribe to the webhook response
    cointimer.start();
    cointimerfunction();  // Trigger initial bitcoin webhook
}


void cointimerfunction(){
     //Particle.publish("bitcoin2");  // Trigger bitcoin webhook
     bool success = Particle.publish("bchpls");  // Trigger bitcoin webhook
     if (success) 
     {
         digitalWrite(ledpin,HIGH);
     }
     
}


void loop() {
    int x=0;
    /*
    for (x=0; x<256; x++) {  //photon DAC current limit approx 10mA 
        analogWrite(DAC1, x);  //max is 4095
        analogWrite(pwmpin, x, 500); //last value is frequency in hz, 1-65535  max is 255
        Serial.println(x); //write is for byte value
        delay(10);
        
        // sets DAC pin to an output voltage of 1024/4095 * 3.3V = 0.825V.
        }
        delay(1000);
     */   
     //analogWrite(pwmpin,random(235),500); //generates randoms up to 235 using 256
     delay(250);
        
    //digitalWrite(ledpin,!digitalRead(ledpin));
}

int setdac(String command) {
    int commandint = command.toInt();
    if ((commandint >=0) && (commandint <=100)){
        commandint = map(commandint, 0, 100, 0, 255); //in low, high to out low, high
        analogWrite(pwmpin, commandint, 500); 
    }
}


void bitcoinHandler(const char *event, const char *data) {  // This is called when the Photon recives the webhook data.
    String latest = String(data);                  // Get the latest price of Bitcoin
    Serial.println(latest);                                     // Print it to serial
    coindac(latest);
    digitalWrite(ledpin, LOW);
    
}

int coindac(String command) {
    int commandint = command.toInt();
    if ((commandint >=1) && (commandint <=10000)){
        commandint = map(commandint, 0, 10000, 0, 258); //in low, high to out low, high
        analogWrite(pwmpin, commandint, 500); 
    }
}
    
/* PARTICLE WEBHOOK CODE - CUSTOM

{
    "event": "bchpls",
    "url": "https://min-api.cryptocompare.com/data/price?fsym=BCH&tsyms=USD",
    "requestType": "GET",
    "noDefaults": false,
    "rejectUnauthorized": true,
    "responseTemplate": "{{USD}}"
}
*/