Basic Arduino Keyer

Several posts back, we made an Arduino Morse code oscillator. These are great if you are only using a standard straight key. To use a paddle you need a keyer. Today we will build a Basic Arduino Keyer. Construction of the keyer is very similar to the Arduino Oscillator. The main difference is the addition of the extra pin. Most of the changes are in the programming.

//Basic Arduino Keyer 6/9/19
//https://MacarrLabs.com/
//https://KM4NMP.com/
//Author Matthew Carr KM4NMP
//common plug pinouts are:
//  Tip – left lever, or left side of single lever, normally Dot
//  Ring – right lever, or right side of single lever, normally Dash
//  Shaft – common

int LeftPin = 2;  //left paddle push pin
int RightPin = 3; //right paddle push pin
int LeftPinState = 0;
int RightPinState = 0;
int audio = 12;   //audio out pin
int note = 600;   //note pitch change for a different tone
int dotTime;
int dashTime;

void setup() {
  Serial.begin(9600);        //for debugging
  pinMode(LeftPin, INPUT);   //set pin as input
  pinMode(RightPin, INPUT);  //set pin as input
  dotTime = 125;             //dot time in milliseconds
  dashTime = dotTime * 3;
}

void loop() {
  LeftPinState = digitalRead(LeftPin);
  RightPinState = digitalRead(RightPin);

  if (LeftPinState == 1) {
    Serial.print("left ");         //for debugging
    Serial.println(LeftPinState);  //for debugging
    tone(audio, note);             //start tone
    delay(dotTime);                //tone length
    noTone(audio);
  }

  if (RightPinState == 1) {
    Serial.print("Right ");         //for debugging    
    Serial.println(RightPinState);  //for debugging
    tone(audio, note);              //start tone
    delay(dashTime);                //tone length
    noTone(audio);
  } 
  delay(dotTime);                   //time between tones
}

Links

https://km4nmp.com/2019/03/31/arduino-morse-code-practice-oscillator-project/

https://km4nmp.com/2019/04/06/arduino-oscillator-with-morse-code-decoder/

https://www.arduino.cc/

https://www.arduino.cc/reference/en/language/functions/advanced-io/tone/

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