robtillaart / ad9833 Goto Github PK

Might overwrite non default parameters.

• have a shadow control register cached?
• functions per field if appropriate

Usage in array of devices

ESP32-S3 does not do VSPI.
ESP32 dependency should be minimized
(remove HSPI/VSPI references, see MCP_DAC #24)

Hi Rob,

Thanks for all the great libraries for Arduino!

I tried the AD9833 (breakout boeard) and it works great.
I also changed the crystal oscillator from 25Mhz to 1Mhz (really easy with a heatgun on the breakout board).
That also works great!

I used the Low level API functions and perfect results.

I think there is a misstake in the documentation:
it says: void writeFrequencyRegister(uint8_t channel, uint32_t freq) channel = 0 or 1, freq = 0 .. 134217728
But I think 134217728 is only half of the possibilities. The datasheet says 2^28, so 268435456.
I'm using the AD9833 for audio, so I cannot hear if it is correct.
But when I changed to the 1Mhz crystal and applied the fMCLK/2^28 × FREQREG function, my tuner said 440 spot on at writeFrequencyRegister(0, 118112)

Greetings,
Bas

Not sure If this is "By design" in the chip,
Or if I have a cheap Chinese counterfeit chip,
Or this is something possible improve in this library

But I get some high frequency signal on the output when I change the frequency when I call the AD.setFrequency() function
The transients last longer if I use the SW SPI , but is still present if using the HW SPI

Using a Arduino Nano Every
Using HW SPI (AD9833 AD(9);)
using square wave (AD.setWave(AD9833_SQUARE1))

This happen only when I change the frequency
But is actually really painful if you plan to sweep frequency !

void set_freq (float f_khz){
  static float old_khz;

  digitalWrite(8,HIGH );
  if(f_khz != old_khz ){
     AD.setFrequency(f_khz*1000.0, 0);
     old_khz=f_khz;
  }
  digitalWrite(8, LOW);

}

The CH1 (yellow) is the AD9833 output
The CH2 (blue) is the pin8 (use to trig the scope on my set_freq() function

Looks quite similar at first sight