nfarrier
Published © GPL3+

Auto-Keyer for Radio "Fox Hunting"

Attach an amateur radio to this and the radio will regularly identify itself so others can use their direction finding skills and locate it.

IntermediateFull instructions provided11,092
Auto-Keyer for Radio "Fox Hunting"

Things used in this project

Hardware components

Arduino UNO
Arduino UNO
×1
Capacitor 100 nF
Capacitor 100 nF
×5
Relay (generic)
×1
LED (generic)
LED (generic)
×1
Capacitor 100 µF
Capacitor 100 µF
×1
Jumper wires (generic)
Jumper wires (generic)
×1
External handset/mic plug for your amateur radio
×1
Toggle Switch, Toggle
Toggle Switch, Toggle
×1

Hand tools and fabrication machines

Soldering iron (generic)
Soldering iron (generic)
Solder Wire, Lead Free
Solder Wire, Lead Free
Amateur Radio

Story

Read more

Schematics

Schematic for the fox hunt radio's keyer

Code

Fox Hunting Radio Keyer

Arduino
The Arduino that keys up the radio to transmit and sends the Morse code to identify itself.
/*By Nelson Farrier
  Key up radio and send tone
  Keys up Baofeng UV-3R radio by turning on and off the relay, then ID's and and sends a 5 second tone.
 */
      
// Pin 12 is connected to a relay.
// Pin 13 is connected to a tone circuit.

//   modified from: Mike Myers (http://mikemyers.me)  @netnutmike
//   Let's Make It Episode 6 (http://tech-zen.tv/index.php/shows/let-s-make-it/episodes/59-sensor-fun-with-arduino-1-massive-failure-but-4-successes-let-s-make-it-episode-6)
//   define the morse code for the alphabet and numbers

char* letters[] = {
  ".-",     // A
  "-...",   // B
  "-.-.",   // C
  "-..",    // D
  ".",      // E
  "..-.",   // F
  "--.",    // G
  "....",   // H
  "..",     // I
  ".---",   // J
  "-.-",    // K
  ".-..",   // L
  "--",     // M
  "-.",     // N
  "---",    // O
  ".--.",   // P
  "--.-",   // Q
  ".-.",    // R
  "...",    // S
  "-",      // T
  "..-",    // U
  "...-",   // V
  ".--",    // W
  "-..-",   // X
  "-.--",   // Y
  "--.."    // Z
};

char* numbers[] = {
  "-----",   // 0
  ".----",   // 1
  "..---",   // 2
  "...--",   // 3
  "....-",   // 4
  ".....",   // 5
  "-....",   // 6
  "--...",   // 7
  "---..",   // 8
  "----."    // 9   --- end of 1st segment of borrowed code from Mike Myers
};

int relay = 12;
int TonePin = 13; 
int frequency = 1000; // frequency of tone

int dotDelay = 70;      // duration of the dot in morse code, this is also the time between the dots and dashes
int charDelay = 500;    // duration of the wait between letters for Farsnworth method
int wordDelay = 1100;   // duration of the wait between words for Farsnworth method
int cycleDelay = 15000;  // HALF the duration because the largest value is 16383

// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(12, OUTPUT);     
  pinMode(13, OUTPUT);     
  delay(2000);  // initial delay after powering on
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(relay, HIGH);   // turn the relay on (HIGH is the voltage level)
  delay(1000);                 // wait for a second
  
  SendText("NF7Z FOX");  

  delay(1000);                 // wait for a second

  tone(TonePin, frequency);    // send 7 sec tone
  delay(7000);
  noTone(TonePin);
  
  delay(10000);                 // 10 seconds transmit w/o tone

  digitalWrite(relay, LOW);    // turn the relay off by making the voltage LOW

  delay(cycleDelay);           // wait for cycle time (because the largest value is 16383)
  delay(cycleDelay);           // wait for cycle time
}

//=================================================================
//
// modified from: Mike Myers (http://mikemyers.me)  @netnutmike
// Function: morseCodeSequence
//
// Input: Character Array of Dots and Dashes to be sent
//
// Description:
//      This function takes as input an array or "." and "-" and
//      calls dotOrDash for each item in the array.
//
//      At the end of the sequence, there is a delay of 3 times 
//      the dot duration.
//=================================================================

void morseCodeSequence(char* sequence)
{
   int i = 0;

   // Loop for each element in the array
   while (sequence[i] != NULL)  
   {
      dotOrDash(sequence[i]);     // Send out the dot or dash
       i++;                        // Increment to the next element in the array
   }
   delay(charDelay);            // gap between letters
}
//=================================================================
//
// Function: SendText
//
// Input: Character Array of text in English
//
// Description:
//      This function takes text as input and sends Morse code for each letter.
//      There then is a pause after each letter.
//
//=================================================================

void SendText(char* MorseCodeLetters)
{
   int i = 0;
   char ch;

   // Loop for each element in the array
   while (MorseCodeLetters[i] != NULL)  
   {
    ch = MorseCodeLetters[i];
    // Is it lowercase letter?
    if (ch >= 'a' && ch <= 'z')
    {
      morseCodeSequence(letters[ch - 'a']);
    }
    else if (ch >= 'A' && ch <= 'Z')    // Uppercase Letter
    {
      morseCodeSequence(letters[ch - 'A']);
    }
    else if (ch >= '0' && ch <= '9')    // Number
    {
      morseCodeSequence(numbers[ch - '0']);
    }
    else if (ch == ' ')                // Space (wait for 4 times dotDelay
    {
     delay(wordDelay);      // gap between words  
    }
    else {
    }
    i++;         // Increment to the next element in the array
   }
   delay(charDelay);            // gap between letters
}

//=================================================================
//
// Function: dorOrDash
//
// modified from: Mike Myers (http://mikemyers.me)  @netnutmike
// Input: Character that should be either a dot or a dash
//
// Description:
//      This function first turns on the output then looks to see 
//      if the character is a "." and if so delays the dotDelay.
//      
//      If the character is not a "." then the routine assumes it
//      is a "-" and keep the output high for 3 times the length of
//      dotDelay.  This could be improved by making sure the 
//      character is a "-" but for most cases it would not matter.
//
//      After the delay time the pin is taken low turning off the 
//      tone.
//
//      Then it delays for one dotDelay time so the dots and dashes
//      do not run together.
//=================================================================

void dotOrDash(char dotOrDash)
{
  tone(TonePin, frequency);
  if (dotOrDash == '.')
  {
    delay(dotDelay);           
  }
  else // must be a -
  {
    delay(dotDelay * 3);           
  }
  noTone(TonePin);
  delay(dotDelay); // gap between flashes
}

Credits

nfarrier

nfarrier

1 project • 8 followers
I'm a retired science and technology teacher, and have an amateur radio license. I enjoy programming and making things.

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