AD9834 initialization

Projects Programming
1

Hi everyone, so I have been banging my head on this for a couple days and I cant figure it out. Pretty much I want a 3MHz sine wave output (but at this point will take any frequency).
I think that my problem is in the initialization, because I can see the SPI data on the SDATA pin, but I just dont get any output.

Any help with this would be great.

My code is shown below

#include <SPI.h>

//const int On_Board_LED = 25;
const int RST = 2;
const int FSYNC1 = 10;  // 5 on the pico


void setup() {
  // put your setup code here, to run once:
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(RST, OUTPUT);
  pinMode(FSYNC1, OUTPUT);


  digitalWrite(LED_BUILTIN, LOW);
  
  digitalWrite(RST, HIGH);  //set reset high (1) as per data sheet
  digitalWrite(FSYNC1, HIGH);


  
  SPI.begin();
  SPI.beginTransaction(SPISettings(5000000, MSBFIRST, SPI_MODE2));
  
  
  AD_RESET();
  AD_FREQ();
  AD_ENABLE();

  
  delay(500);
  digitalWrite(RST, LOW);  //Now that we are ready to generate output set to 0 (LOW)
}

void AD_RESET(){
  
  digitalWrite(FSYNC1, LOW); 

  SPI.transfer(0x21);  //MSB   These 2 are for control register
  SPI.transfer(0x00);  //LSB  

  digitalWrite(FSYNC1, HIGH);
  delay(10);


  digitalWrite(FSYNC1, LOW);

  SPI.transfer(0x50);   //These 2 are for frequency register 0 LCB
  SPI.transfer(0xC7);
  
  SPI.transfer(0x40);   //These 2 are for frequency register 0 MSB
  SPI.transfer(0x00);

  delay(10);

  SPI.transfer(0x82);
  SPI.transfer(0x7E);  //These were a test from some code I saw online
  SPI.transfer(0xBE);  //Not sure where the values come from though
  SPI.transfer(0x3F);


  SPI.transfer(0x20);  //These two Lines Exit Reset
  SPI.transfer(0x00);

}

void AD_FREQ(){
  //digitalWrite(On_Board_LED, HIGH);
  

 
  digitalWrite(FSYNC1, LOW);
 
  //These 4 SPI trasfer lines are for setting the frequency
  //Refer to the Data sheet for how this is done
  SPI.transfer(0x7B);
  SPI.transfer(0x60);
  
  SPI.transfer(0x7F);
  SPI.transfer(0x7C);

  
  //This is setting the phase of the signal to 0 phase adjustment
  SPI.transfer(0x00);
  SPI.transfer(0x00);
  digitalWrite(FSYNC1, HIGH);

  
}


void AD_ENABLE(){
  
  digitalWrite(FSYNC1, LOW);
  SPI.transfer(0x22);
  SPI.transfer(0x00);
  digitalWrite(FSYNC1, HIGH);

}


void loop() {
  // put your main code here, to run repeatedly:
  
  digitalWrite(LED_BUILTIN, HIGH);

  
}

just for your info FSYNC1 IS CS/SS
and RST is reset

Edit: Here is a link to the AD9834 Application Note which is where I got the HEX values, page 3 table 1: https://www.analog.com/media/en/technical-documentation/application-notes/an-1070.pdf

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