Some of my projects and technical posts



The WA5BDU Keyer – An Arduino keyer that can be used in a minimal mode, or as a full-featured keyer.

An Arduino Si5351a Quadrature VFO Controller – Takes a basic Si5351a control scheme and expands it to a full-featured VFO including band changing, step size selection, CW pitch offset with a T/R input to alternate between TX and RX frequencies, RIT, USB/LSB selection and more.


Programming the Si5351a synthesizer – This page is not a construction article, but is a discussion of how registers which control the frequency and phase of the Si5351a are calculated.



An Arduino Frequency Counter – Here’s an Arduino frequency counter that uses the 74LV8154 32-bit counter IC. A simple version uses the Arduino’s clock for a time base and a more accurate version uses a HEF4521B 24-bit divider plus crystal oscillator IC to provide a 1 second time base.