DSP AM/FM Radio Kit
As an amateur radio operator (and even well before that) I’ve always had a soft spot for radio. It’s such an amazing technology, and I’ve always had various radios and radio kits around. This DSP-based Dual Band AM/FM Radio is a very nifty little project that explores the digital realm of modern radio.
The project is based around the Skyworks (formerly Silicon Labs) SI4730 chip. This chip integrates everything needed for a modern radio, from the front-end amplifier and mixer blocks to the DSP decoder and digital/analog audio outputs. It’s pretty incredible that a QFN20 chip can contain an entire AM/FM radio when in the not-too-distant past it required many discrete semiconductors, op-amps, mixers, variable capacitors, and more. Now you get very high-quality audio, all controlled via either I2C or SPI-like interfaces.
This kit takes that chip and pairs it with a rotary encoder & buttons, a 0.96″ OLED screen, and external antenna and speaker connections. The speaker output has an LM386 amplifier providing up to 1W of output, which is plenty for a small system like this. The system also uses an ATmega328P, so you can easily modify the firmware to explore all the features of the Si4730.
If you want to explore the world of short- and longwave, JasonKits also sells a similar kit based around the Si4375 Quad Band AM/FM/SW/LW chip. The latest revision has some fancy new features, including a 17dB pre-amp on the shortwave input, allowing weaker stations to be tuned in more reliably.
Dive into the world of digital radio with one of these awesome kits!
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