This repository contains the schematic, PCB design files and a basic firmware stack for the Hardware Interface of the Lightweight Autonomous Racing System (LARS).
The board is based on a STM32F4 microcontroller and is designed to interface with various sensors and actuators on the vehicle. The communication with the host PC is done via USB, using micro-ROS and the underlying micro-XRCE DDS.
This project is licensed under the GNU General Public License v3.0. You can freely use, modify, and distribute this code as long as you comply with the terms of the license.
The hardware design files are released under the CERN Open Hardware Licence v2.
- STM32F429 microcontroller (Cortex-M4, 180MHz, 2MB Flash, 256KB RAM)
- Board dimensions: 86 x 86 mm
- SWD interface for programming and debugging
- Boot-/Reset header for flashing via USB
- User- and Reset buttons
- RGB Debug LEDs
- 5V power supply via XT30 connector or USB (XT30 will be prioritized)
- Power input range: 4.8V - 5.3V
- "Reverse polarity protection"
- On-board 3.3V voltage regulator
- Switchable 5V output for external devices
- Additional 3.3V and 5V output
- 2x USB-C (2.0 Fullspeed) for host PC and debugging/flashing
- CAN-Bus (with optional termination)
- 8x I2C
- 3x UART
- 2x SPI
- 2x Servo (with analog feedback)
- 2x WS2812 LED strip
- Buffered and filtered analog inputs
- Additional Timer channels and GPIOs
- 3.3V and 5V output for external devices
- 4A/8A polyfuse on the main power input
- "Rudimentary" reverse polarity protection
- Back-power protection for both power inputs (USB and XT30)
- TVS diodes against voltage spikes on all power rails
- Current limited 5V output (max 2.4 A)
- All data lines are 5V tolerant
- Additional short-circuit, overcurrent and -voltage protection up to ~20V on all interfaces
The board was designed in KiCad 9.0. The project file can be found in the /PCB/KiCad directory.
A full Schematic of the board can be found as a PDF in the /PCB directory.
All PCB design files, a bill of materials and Gerber Files for manufacturing at JLCPCB can be found in the /PCB/manufacturing directory.
A 3D STEP model of the board can be found in the /PCB/export directory.