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AD9833 FSK

Question asked by plasmaphase on Feb 7, 2013
Latest reply on Feb 7, 2013 by plasmaphase

I believe I've successfully programmed the Frequency Register 0 and Frequency Register 1 correctly (at least I think I have), however, I'm having issues swapping between the two.  Here's my commands so far:

 

AD9833_write_register(0x2100); //set device in reset and trigger 28-bit write

AD9833_write_register(0x618E); // LSB of 800Hz

AD9833_write_register(0x4000); // MSB of 800Hz

AD9833_write_register(0x2100); //continue reset, and enable write to FR1

AD9833_write_register(0x90C7); //LSB of 400Hz

AD9833_write_register(0x8000); //LSB of 400Hz

AD9833_write_register(0x0800); //Reset low, FSELECT = 0

 

At this point I'm interested in being able to loop, switching between the two frequencies.

while(1)

{

freq 0 output;

delay

freq 1 output

delay

}

 

Looking for some advice as to what I'm doing wrong, and what to do next.  Is it basically this?

 

while(1)

{

AD9833_write_register(0x0000); //FSELECT 0

Delay(500);

AD9833_write_register(0x0800); //FSELECT 1

Delay(500);

}

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