Author’s summary: The author reminisces about building a crystal radio in the past, sparking an interest in electronics. The Pi Pico Rx, based on the Raspberry Pi Pico, is introduced as a simple SDR receiver solution covering LW, MW, and SW bands, capable of receiving signals worldwide. The design uses unique features like the “Tayloe” Quadrature Sampling Detector and a quadrature oscillator generated via the PIO feature of the RP2040. The hardware includes a preamplifier and low-pass filters, with an emphasis on simplicity and cost-effectiveness. The user interface features an OLED display and PWM audio output for headphones or speakers. Other SDR projects are mentioned for inspiration.
https://101-things.readthedocs.io/en/latest/radio_receiver.html