ADF4351

Code to control your ADF4351 board using Arduino. Written from scratch using official datasheet.

Pinout

• Arduino pin #13 <-> CLK
• Arduino pin #11 <-> DATA
• Arduino pin #9 <-> LE

1. Use voltage dividers, ADF runs on 3.3V supply.
2. You can change LE pin assignment to any other IO pin.

Keyboard

• x/c -/+ 10 Hz
• s/d -/+ 100 Hz
• w/e -/+ 1 kHz
• 2/3 -/+ 10 kHz
• 1/4 -/+ 100 kHz
• 5/6 -/+ 10 MHz
• / toggle RF output
• + increase RF power

Modifications

#define REF_CLK 25000000 - if you're using custom reference frequency, set it here

uint8_t slave_select_pin = 9; - this pin can be set to any other IO you like

unsigned long long frequency = 1000000000; that's a default frequency after power on

Set those two variables if you'd like to use this code for non-interactive operation (eg. LO for an upconverter):

uint8_t rf_ena = 1; // 0 - output disabled

uint8_t out_pwr = 0; // 0 - min, 3 - max

You can modify value of r_counter and clock_divider according to your needs. Decreasing step resolution will result in smaller phase noise.

Even when rf_ena is set to 0, the PLL is running and you can expect more than -50 dBm of signal at the output.

QO-100

I'm using this code to directly generate CW on QO-100, so the serial port output shows the downlink frequency (+10489000 kHz) in brackets:

FREQ: 2400060100 ( 560.50 )