Test Sketch for the Kanga DDS Shield

Kanga_DDS_Shield_Test

/*
Kanga_DDS_Shield_Test

Simple test sketch for the DDS Shield
Set up and output 1MHz

See: http://m0xpd.blogspot.co.uk/p/kanga-uk-resources.html

m0xpd
September 2013

 */


// set pin numbers (assuming the default pin assignment)...
const int W_CLK = 2;
const int FQ_UD = 3;
const int DATA = 4;
const int RESET = 5;
// set frequency...
double   freq = 1000000;

#define pulseHigh(pin) {digitalWrite(pin, HIGH); digitalWrite(pin, LOW); }

void tfr_byte2(byte data)
{
  shiftOut(DATA, W_CLK, LSBFIRST, data);
} 


void sendFrequency(double frequency) {
  int32_t freq = frequency * 4294967295/125000000;  
  for (int b=0; b<4; b++, freq>>=8) {
    tfr_byte2(freq & 0xFF);
  }
  tfr_byte2(0x000);   
  pulseHigh(FQ_UD);  
}

void setup() { 
  pinMode(FQ_UD, OUTPUT);
  pinMode(W_CLK, OUTPUT);
  pinMode(DATA, OUTPUT);
  pinMode(RESET, OUTPUT);

  pulseHigh(RESET);
  pulseHigh(W_CLK);
  pulseHigh(FQ_UD);  

  sendFrequency(freq);  
}

void loop(){
//  .. sit doing nothing!
}