/thermostat

Primary LanguageGoMIT LicenseMIT

Thermostat

./img/thermostat.jpeg

./img/thermostat-back.jpeg

Notes and Parts

Rotary Encoder

digikey part number: 118-PEC11R-4320F-S0012-ND https://www.digikey.com/en/products/detail/bourns-inc/PEC11R-4320F-S0012/4699235?so=84473212&content=productdetail_US&mkt_tok=MDI4LVNYSy01MDcAAAGP7gCMSmK3S7iQMFn5oT0O7WjvWYwZCCJSnY_UqbFVAni8uOG82dcPK6wfp3T7Dy_SS-4I20sn1ZHBDY0ZDDaqZXyvshl6x9CQ6nFVvuls

Epoll

https://github.com/davecheney/gpio/blob/master/gpio_linux.go

Hardware Debounce

https://raspberrypi.stackexchange.com/questions/118349/what-is-the-proper-way-to-debounce-a-gpio-input https://www.digikey.com/en/articles/how-to-implement-hardware-debounce-for-switches-and-relays

OLED

AZDelivery I2C 0.96-inch OLED Display • Compatible with Arduino SSD1306 & Raspberry Pi • Set of 3 • 128x64 Pixels IIC 3.3V 5V White Character Screen Module https://www.amazon.com/gp/product/B074N9VLZX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Arduino Example

Rotary encoder decoding using two interrupt lines. Most Arduino boards have two external interrupts, numbers 0 (on digital pin 2) and 1 (on digital pin 3).

Program sketch is for SparkFun Rotary Encoder sku: COM-09117 Connect the middle pin of the three to ground. The outside two pins of the three are connected to digital pins 2 and 3

volatile int number = 0;                // Testnumber, print it when it changes value,
                                        // used in loop and both interrupt routines
int oldnumber = number;

volatile boolean halfleft = false;      // Used in both interrupt routines
volatile boolean halfright = false;

void setup(){
  Serial.begin(9600);
  pinMode(2, INPUT);
  digitalWrite(2, HIGH);                // Turn on internal pullup resistor
  pinMode(3, INPUT);
  digitalWrite(3, HIGH);                // Turn on internal pullup resistor
  attachInterrupt(0, isr_2, FALLING);   // Call isr_2 when digital pin 2 goes LOW
  attachInterrupt(1, isr_3, FALLING);   // Call isr_3 when digital pin 3 goes LOW
}

void loop(){
  if(number != oldnumber){              // Change in value ?
    Serial.println(number);             // Yes, print it (or whatever)
    oldnumber = number;
  }
}

void isr_2(){                                              // Pin2 went LOW
  delay(1);                                                // Debounce time
  if(digitalRead(2) == LOW){                               // Pin2 still LOW ?
    if(digitalRead(3) == HIGH && halfright == false){      // -->
      halfright = true;                                    // One half click clockwise
    } 
    if(digitalRead(3) == LOW && halfleft == true){         // <--
      halfleft = false;                                    // One whole click counter-
      number--;                                            // clockwise
    }
  }
}

void isr_3(){                                             // Pin3 went LOW
  delay(1);                                               // Debounce time
  if(digitalRead(3) == LOW){                              // Pin3 still LOW ?
    if(digitalRead(2) == HIGH && halfleft == false){      // <--
      halfleft = true;                                    // One half  click counter-
    }                                                     // clockwise
    if(digitalRead(2) == LOW && halfright == true){       // -->
      halfright = false;                                  // One whole click clockwise
      number++;
    }
  }
}