Introduction

The 12V -> 5V @ 4A Buck Converter + ELRS Board is intent for several foam fixed wing planes at the Waterloo Aerial Robotics Group. It includes a ESP32-C3 for PWM signaling and SX1281 for RF control over ELRS, as well as the requisite power electronics to have the system be powered by a single 12V input (1x 3S battery).

...

This board is designed to use a single 3S battery for input power. This will split the power into two output XT60 connectors, and feed to the buck converter, which, in combination with an LDO, powers the rest of the device.

The power rail is rated for an absolute maximum of 16.9V, accounting for LiPo battery overcharging and input transients (voltage spikes from hot-plugging a high-inductance battery). Usage of a battery with an anti-spark connector is recommended.

Do NOT leave the U.FL connector unoccupied when powering on the device. This could destroy the amplifier in the SX1281 RF IC.

...

This board was built to follow the Generic C3 2400 PWM target in the ExpressLRS examples on GitHub. The pin definition is as shown.

...