Things used in this project

Hardware components:
Photon new
Particle Photon
×1
Temperature probe
×1
2.5mm audio jack.
×1
Hand tools and fabrication machines:
09507 01
Soldering iron (generic)

Schematics

BBQ breadboard
bbq.fzz
BBQ schematic
Bbq bb

Code

Photon firmwareC/C++
Comile and upload via the web IDE for Photon devices.
// these values are for Maverick PR-003 probe, which works with devices Et-71/72/73/901
//float steinhart_a = 0.00024723753;
//float steinhart_b = 0.00023402251;
//float steinhart_c = 0.00000013879768;

//float c;
//float k;
//float f;
int boardLed = D7;
int therm = A0;
int therm2 = A1;
int resistance;
int resistance2;

void setup() {
    pinMode(boardLed,OUTPUT);
    pinMode(therm,INPUT); 
    pinMode(therm2,INPUT); 
    //Particle.variable("therm", &measure, INT);
    Particle.variable("resistance", &resistance, INT);
    Particle.variable("resistance2", &resistance2, INT);
    RGB.control(true);
    pinMode(D0, INPUT);
}

void loop() {
  int measure = 0;
  for (int x=0; x<8; x++) {
    measure += analogRead(therm);
    delay(10);
  }
  measure /= 8;
  //resistance = 150000;
  resistance = int(10000.0 / (4095.0/measure - 1.0));
  
  int measure2 = 0;
  for (int x=0; x<8; x++) {
    measure2 += analogRead(therm2);
    delay(10);
  }
  measure2 /= 8;
  //resistance = 150000;
  resistance2 = int(10000.0 / (4095.0/measure2 - 1.0));
  
  // Steinhart equations for calculating temp. 
  //float ln_resistance = ln(resistance);
  //k = 1/(steinhart_a+steinhart_b*ln_resistance+steinhart_c*(ln_resistance*ln_resistance*ln_resistance));
  //c = k-273.15;
  //f = c*1.8+32;
  //char f_char[6];
  char m_char[8];
  char r_char[8], r_char2[8];
  //sprintf(f_char,"%d", f);
  //sprintf(m_char,"%d", measure);
  sprintf(r_char,"%d", resistance);
  sprintf(r_char2,"%d", resistance2);
  //Particle.publish("therm",m_char);
  Particle.publish("resistance",r_char);  
  Particle.publish("resistance2",r_char2);
  //Particle.publish("temp",f_char);
  if (digitalRead(D0)) {
    digitalWrite(boardLed,HIGH);
    delay(500);
    digitalWrite(boardLed,LOW);
    delay(10000);
  }
}
BBQ Android App
Import into Android Studio and compile and upload to your phone. Requires usb-debugging to be enabled on your phone to upload.

Credits

Photo
Michael Hartman
1 project • 2 followers
ASIC/SoC Hardware Engineer by trade.
Contact

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