Getting an AD 9850BRS Working

An AD 9850BRS is an IC that lets you create radio frequency waveforms. The output frequency is controlled by a serial connection. Phil bought a board that includes one and some control circuitry. It's labeled HC-SR08. We were eventually able to get it working.

Here's what it looks like:

The daughter board.

We used an Arduino Due, which runs at 3.3V, but from looking at the data sheet for the chip, I think it should work on 5V Arduinos as well. We ended up using this Arduino library. We connected the following pins on the daughter board to the Arduino:

  • W_CLK   ->   7
  • FQ_UD   ->   8
  • DATA   ->   9
  • RESET   ->   10
  • VCC   ->   3.3V
  • GND   ->   GND

We found the example code in that Github to be silly. This worked for us:

  #include <AD9850.h>

  const int W_CLK_PIN = 7;
  const int FQ_UD_PIN = 8;
  const int DATA_PIN = 9;
  const int RESET_PIN = 10;

  double freq = 4000000;
  double trimFreq = 124999500;

  int phase = 0;

  void setup(){
    DDS.setfreq(freq, phase);

  void loop(){

Check it out:

The waveform.

Author | Ben Wiener

Background in physics. Also interested in computing, robotics, hiking, woodworking, and other things.