IMG_20131001_100900

Dengan menggunakan arduino kita dapat mengatur frekuensi output dari DDS9850. Berikut adalah program yang dapat digunakan.

Output yang dihasilkan.

50 khz

100 khz sine 1 dan sine 2

Video


/*
* A simple single freq AD9850 Arduino test script
* Original AD9851 DDS sketch by Andrew Smallbone at www.rocketnumbernine.com
* Modified for testing the inexpensive AD9850 ebay DDS modules
* Pictures and pinouts at nr8o.dhlpilotcentral.com
* 9850 datasheet at http://www.analog.com/static/imported-files/data_sheets/AD9850.pdf
* Use freely
*/

#define W_CLK 8       // Pin 8 - connect to AD9850 module word load clock pin (CLK)
#define FQ_UD 9       // Pin 9 - connect to freq update pin (FQ)
#define DATA 10       // Pin 10 - connect to serial data load pin (DATA)
#define RESET 11      // Pin 11 - connect to reset pin (RST).

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

// transfers a byte, a bit at a time, LSB first to the 9850 via serial DATA line
void tfr_byte(byte data)
{
for (int i=0; i<8; i++, data>>=1) {
digitalWrite(DATA, data & 0x01);
pulseHigh(W_CLK);   //after each bit sent, CLK is pulsed high
}
}

// frequency calc from datasheet page 8 = <sys clock> * <frequency tuning word>/2^32
void sendFrequency(double frequency) {
int32_t freq = frequency * 4294967295/125000000;  // note 125 MHz clock on 9850
for (int b=0; b<4; b++, freq>>=8) {
tfr_byte(freq & 0xFF);
}
tfr_byte(0x000);   // Final control byte, all 0 for 9850 chip
pulseHigh(FQ_UD);  // Done!  Should see output
}

void setup() {
// configure arduino data pins for output
pinMode(FQ_UD, OUTPUT);
pinMode(W_CLK, OUTPUT);
pinMode(DATA, OUTPUT);
pinMode(RESET, OUTPUT);

pulseHigh(RESET);
pulseHigh(W_CLK);
pulseHigh(FQ_UD);  // this pulse enables serial mode - Datasheet page 12 figure 10
}

void loop() {
sendFrequency(10.e6);  // freq
while(1);
}

Demikian, semoga bermanfaat.

Reference:

Testing an eBay AD9850 DDS module with Arduino Uno