Hunter Adams has tuned in to a really cool idea with his latest Raspberry Pi project. Using our favorite microcontroller, the Raspberry Pi Pico, he’s managed to create an RP2040-powered AM Radio transmitter. This project is a great example how versatile this microcontroller can be when you implement the right accessories with a dash of ingenuity.
Adams was kind enough to share a demo video of the set up in action with impressive results. He also delves deeper into the configuration of the hardware and how you can recreate it at home. It works by accepting audio input from a microphone that is processed and then sent to a Pico to be transmitted over a carrier wave.
It’s worth noting that this project may or may not be legal to duplicate depending on where you live. Some localities require a license to broadcast radio signals. If you want to make something similar, please take the time to verify the legalities of this project before you whip out your soldering iron.
If you’ve determined it’s acceptable to recreate this at home, you’ll need a little hardware to get started. Of course, you’ll need a Raspberry Pi Pico with headers if you don’t want to solder the connections to a permanent state. Adams is also using an ADC FIFO module to process the microphone input. It helps to have some jumper wires on hand and a radio nearby to test the results of your setup.
According to Adams, the RP2040 samples input from the microphone at 10,000 Hz. This audio is condensed into 8-bit form before its sent to the ADC FIFO. A DMA channel is used to send the sample to a PWM channel. Because the setup is designed using peripherals, it doesn’t take up any usage of the CPU on the Pico.
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Ash Hill is a Freelance News and Features Writer at Tom's Hardware US. She manages the Pi projects of the month and much of our daily Raspberry Pi reporting.