Raspberry Pi Pico HAM Transmitter Uses Onboard PIO for Oscillator

Raspberry Pi
(Image credit: Jon Dawson, 101 Things)

In the maker world, if you want something that you don’t have, you might want to make it yourself. If you’re not sure where to begin, Jon Dawson’s 101 Things channel is a great place to start. Today we’re sharing a really cool project he’s put together using our favorite microcontroller, the Raspberry Pi Pico. With it, he’s managed to create a HAM radio transmitter and was kind enough to share all the details about how it goes together.

With the finished project, Dawson can transmit single-sideband, AM, FM, and even CW. It has a supported range of between 500 KHz and 30 MHz. We should also note that while you can create this from scratch and it’s really fun to play around with, the legality of HAM radio varies around the world, so take time to double-check local regulations before recreating this project yourself.

According to Dawson, most other transmitter designs require an external piece of hardware to serve as the RF oscillator. In this design, he takes advantage of the Raspberry Pi Pico’s onboard PIO to perform as the oscillator. Dawson explains, however, that this is still a bit of a prototype project and it would need both a filter and amplifier before it could be used for broadcasting purposes.

As this prototype is more of a proof-of-concept, the current build is put together with a piece of copper-clad PCB. Dawson is also using an analog multiplexer alongside a MAC9814 microphone. In the build video, Dawson confirms that you can use the Pico’s ADC for audio input or use a PC to send audio via USB.

The software for this Raspberry Pi project was created from scratch by Dawson and is written in both Python and C++. You can get an up-close look at the code used in this project over at GitHub. Those interested in this project can also access a tutorial video shared on YouTube along with a blog post over at the official 101 Things website.

Ash Hill
Contributing Writer

Ash Hill is a contributing writer for Tom's Hardware with a wealth of experience in the hobby electronics, 3D printing and PCs. She manages the Pi projects of the month and much of our daily Raspberry Pi reporting while also finding the best coupons and deals on all tech.