C5VRX: watch 5.8 GHz FPV drone video on a $7 XIAO ESP32-C5

C5VRX by Twotoz is an analog FPV video receiver built from one Seeed Studio XIAO ESP32-C5 and seven resistors. Analog FPV drones still send their camera feed as FM video on 5.8 GHz, and C5VRX receives it with the ESP32-C5's own Wi-Fi radio, with no extra RF chip. It pulls raw I/Q samples off the radio at 40 MS/s, demodulates the FM video in the chip's BitScrambler peripheral with no CPU in the sample path, and drives a 6-bit resistor DAC on pins D4 to D9 to make composite (CVBS) PAL or NTSC video for goggles, a DVR or any monitor with an AV input. Six resistors (8.2k, 3.9k, 2.0k, 1.0k, 470 and 240 ohms) run from the pins to one node, and a 200-ohm resistor from that node to ground is the load; pin order matters, and a swapped pair gives a scrambled picture. You flash it from the browser with the project's web flasher (Chrome or Edge with Web Serial) or build it with ESP-IDF 6.0.2. On first boot, ideally with the drone's video transmitter off, it calibrates for a few minutes (at most eight) and stores the results. After that the BOOT button steps through channels, and a 0.6-second hold opens an on-screen menu for band, channel, a 48-channel scan, video standard, output level, gain and a sync flywheel. There is also a DAC self-test pattern and a USB serial console with diagnostics. This is the current C5VRX-5 generation, a fast-moving, GPL-3.0 project: the author says on Hackaday that it is heavily AI-driven and not perfect, and the README marks several features as host-tested or with a board test still pending, so expect rough edges. A community side-by-side range test of C5VRX-5 against C5VRX-4 is on YouTube. It's a cheap build: Seeed listed the XIAO ESP32-C5 at $6.99 on October 21, 2026, plus 1% metal-film resistors, perfboard, a 5.8 GHz antenna for the board's U.FL connector and an AV video lead for your goggles, flashed over a USB data cable.