Build a 5.8 GHz analog FPV receiver with a Seeed Studio XIAO ESP32-C5, a resistor DAC and C5VRX firmware. The decoded picture goes to a composite video monitor or goggles. An optional browser console provides USB controls.

Open the USB console · Wiring diagram · Build guide

This companion adapts the wiring and receiver instructions from C5VRX by Twotoz and the C5VRX contributors. The firmware source is included as a pinned Git submodule, without modifications. Visit the official C5VRX website for the original project, web flasher and Discord invite. This is an unofficial build companion, not an official C5VRX release or an independently invented receiver. Source provenance and licenses.

Machine-readable parts list. This receives analog FPV video; it does not decode proprietary digital FPV systems.

1. Assemble the six resistor branches exactly as shown in the diagram. Each branch joins the same VIDEO node. Add the shunt and filter to ground, then connect VIDEO and GND to the display's composite input. Full pin table.
2. Power the receiver through its normal USB input. Power the camera/transmitter according to its own specification; do not power it from the XIAO's 3.3 V pin.
3. Install C5VRX using its official web flasher. Flashing replaces the program on the board. Record the release installed.
4. Close the flasher so it releases USB. Select the matching channel using the board's BOOT button or the optional USB console.
5. View the picture on the analog monitor or goggles. The browser console shows serial messages; it does not receive video over the XIAO's USB port.

The reference network includes a 200 Ω shunt. The connected display may add its own 75 Ω termination. Check the loaded VIDEO level and sync with your actual display; do not add another 75 Ω resistor blindly.

git clone --recurse-submodules https://github.com/codingard/esp32-fpv-receiver.git
cd esp32-fpv-receiver

If you already cloned without submodules:

git submodule update --init --recursive

The firmware is in firmware/C5VRX/, pinned to b8d32b90f479feff7fbb34e6ca01cc9ba2d0d697. It retains its upstream license, notices and history. The upstream web flasher can install a newer release; use the source build instructions when you need this exact revision.

The interface recreates the original FPV animation's instrument layout: receiver controls on the left, frequency readout above spectrum and waterfall panels. Frequency, channel and bandwidth are populated only from actual C5VRX diagnostic lines, with a report timestamp. They clear on disconnect or a new settings request. These are snapshots; press Read device settings after changing the board outside the browser. Channel and gain buttons also request a fresh diagnostic report.

Spectrum and waterfall remain empty, including when a board is connected. The pinned firmware's USB console does not export a continuous FFT-bin stream. This version implements no spectrum input adapter or FFT renderer; supporting live plots requires a separately implemented and validated firmware data path. The 40 MS/s label describes the firmware design, not a browser measurement. There are no cosmetic sliders that pretend to configure unsupported FFT settings.

Use desktop Chrome or Edge on HTTPS or localhost. The console opens USB at 115200 baud and offers the documented diagnostics, next-channel and manual-gain commands. It displays only text received from the device. Selecting a serial port does not itself prove it is a C5VRX receiver; check the firmware output.

Run locally with Python 3:

python3 -m http.server 4174 --bind 127.0.0.1 --directory web

Open http://127.0.0.1:4174. No packages or backend are required. There is no simulated data, noise generator, video playback, analytics or upload service. Logs stay in your browser until you explicitly download them. Close other serial monitors before connecting. Changing channel or gain can interrupt the picture; perform setup on the bench.

C5VRX acquires raw I/Q through the ESP32-C5 RF diagnostic path at 40 MS/s, uses BitScrambler for wideband FM demodulation, and drives the six-bit resistor DAC through PARLIO. The DAC produces analog composite video. A background CPU task manages settings while dedicated peripherals carry the continuous pixel path. These mechanisms and the hardware design come from C5VRX.

This companion has not been bench-tested with a physical receiver. The upstream project documents its own hardware results and remaining limitations; those are not tests of this companion. The browser transport has automated checks, and the published guide is checked against the pinned upstream pinout. No claim is made about range, latency, RF sensitivity or reliable flight use.

The social spectrum animation was a synthetic illustration. It is not a recording of decoded FPV video and is not included as measurement evidence here. The actual receiver output is the analog picture on your attached monitor.

Run npm test with Node.js 20+ for the console transport and wiring checks. See physical acceptance steps before marking a build tested.

• No USB port: check the data cable, desktop browser and USB access. Close the flasher and serial monitors before opening the console.
• Connected but no logs: click Diagnostics. Confirm the correct port, C5VRX firmware and 115200 baud. A USB connection is not an RF-lock indication.
• No picture: check the analog input, common ground, matching transmitter channel, antenna and all six DAC branches. Verify VIDEO level under load.
• Noise, grain or unstable sync: consult the upstream diagnostics and current known limits. Do not assume a different resistor value or gain setting is a validated fix for every receiver.
• Need video in a browser: use a separate compatible analog-to-USB video capture device; this console does not implement that additional path.

C5VRX by Twotoz and the C5VRX contributors is licensed under GPL-3.0-only. This companion's original console, diagram and adapted documentation are also released under GPL-3.0-only. Upstream notices remain in the firmware submodule. C5VRX branding has separate terms; no upstream logo is reused here. Espressif, Seeed Studio and other third-party names belong to their respective owners.