Digital Thermometer Sketches

SevenSegment.ino

const uint8_t DATA = 7;
const uint8_t OUTPUT_ENABLE = 8;
const uint8_t LATCH = 9;
const uint8_t CLOCK = 10;
const uint8_t CLEAR = 11;

const uint8_t Zero  = 0x3F;
const uint8_t One   = 0x06;
const uint8_t Two   = 0x5B;
const uint8_t Three = 0x4F;
const uint8_t Four  = 0x66;
const uint8_t Five  = 0x6D;
const uint8_t Six   = 0x7D;
const uint8_t Seven = 0x07;
const uint8_t Eight = 0x7F;
const uint8_t Nine  = 0x6F;

// Wire normally, but mount the display inverted so the decimal point is top left.
const uint8_t Celcius = 0x8F;
const uint8_t Farenheit = 0xCE;

const uint8_t Characters[] = {Zero,One,Two,Three,Four,Five,Six,Seven,Eight,Nine, Celcius, Farenheit};

void setup() 
{
  // Setup the pins connected to the shift register.
  pinMode(DATA, OUTPUT);
  pinMode(CLOCK, OUTPUT);
  pinMode(LATCH, OUTPUT);
  pinMode(OUTPUT_ENABLE, OUTPUT);
  pinMode(CLEAR, OUTPUT);

  //Hold OutputEnable low so we can display.
  digitalWrite(OUTPUT_ENABLE, LOW);
  //Hold Clear High so we don't reset as we're trying to display.
  digitalWrite(CLEAR, HIGH);

  //Initalize our clock low so we know it's inital state.
  digitalWrite(CLOCK, LOW);
}

void loop() 
{
   // put your main code here, to run repeatedly:
  const int OneSec = 1000; 

  int8_t i;
  for(i = 0; i < 12; i++)
  {
    writeToDisplay(Characters[i]);
    delay(OneSec);
  }

/* Blast off countdown */
//  for(i = 9; i >= 0; i--)
//  {
//    writeToDisplay(Characters[i]);
//    delay(OneSec);
//  }
}

void writeToDisplay(uint8_t character)
{
   //Make sure latch is low so we display all segments at once.
   digitalWrite(LATCH, LOW);  
   // circuit uses a common anode, so it pulls the segments to ground to activate; i.e. active LOW
   // Because it's easier to think of 1 as on, NOT the bits before writing them.
   shiftOut(DATA, CLOCK, MSBFIRST, ~character); 
   digitalWrite(LATCH, HIGH); //send it
   digitalWrite(LATCH, LOW);  //reset the latch;
}

SevenSegment_Celcius_Farenheit_Switch.ino

const uint8_t CF_SWITCH = 2;
const uint8_t DATA = 7;
const uint8_t OUTPUT_ENABLE = 8;
const uint8_t LATCH = 9;
const uint8_t CLOCK = 10;
const uint8_t CLEAR = 11;

typedef uint8_t displayChar_t; 
const displayChar_t Celcius = 0x8F;
const displayChar_t Farenheit = 0xCE;

void setup() {
  //Setup switch input for ºC/ºF
  pinMode(CF_SWITCH, INPUT_PULLUP);
  
  // Setup the pins connected to the shift register.
  pinMode(DATA, OUTPUT);
  pinMode(CLOCK, OUTPUT);
  pinMode(LATCH, OUTPUT);
  pinMode(OUTPUT_ENABLE, OUTPUT);
  pinMode(CLEAR, OUTPUT);

  //Hold OutputEnable low so we can display.
  digitalWrite(OUTPUT_ENABLE, LOW);
  //Hold Clear High so we don't reset as we're trying to display.
  digitalWrite(CLEAR, HIGH);

  //Initalize our clock low so we know it's inital state.
  digitalWrite(CLOCK, LOW);
}

void loop() {
  
  int state = digitalRead(CF_SWITCH);
  displayChar_t displayChar = (HIGH == state) ? Celcius : Farenheit;

     //Make sure latch is low so we display all segments at once.
   digitalWrite(LATCH, LOW);  
   // circuit uses a common anode, so it pulls the segments to ground to activate; i.e. active LOW
   // Because it's easier to think of 1 as on, NOT the bits before writing them.
   shiftOut(DATA, CLOCK, MSBFIRST, ~displayChar); 
   digitalWrite(LATCH, HIGH); //send it
   digitalWrite(LATCH, LOW);  //reset the latch;
}