NOTE: Documentation in progress!

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 and SX1281 for RF control over ELRS, as well as the requisite power electronics to have system be powered by a single 12V input (1x 3S battery).

This implementation is designed to optimize and integrate the system of the foam fixed-wings, which currently requires a separate buck converter (previously using 12V->5V @ 5A Buck Converter Board), and a commercial, off-the-shelf ELRS receiver (https://betafpv.com/products/elrs-micro-receiver).

By implementing the two main features on a single 30.5x30.5mm board, we save on weight, size, and complexity of the foam plane’s overall system.

This board does not currently integrate an ESC for motor control.

Usage

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.

Schematic

Altium 365 | 12V-5V 4A Buck with ELRS