Aero Zero

Aero-Zero Custom Flight Controller

I started this project, because I wanted to build fully autonomous ai drone. When I looked at the flight controllers available on the market, they were full of hardware that I just do not need or just that I could not add things that I want (for example the Rasberry pi zero 2w) . Most boards also waste a lot of space on powering analog OSD chips, which is completely useless for me because I am flying a purely digital HD system like Walksnail Avatar. Because the technology changed and digital is the standard now, I realized it is just a waste of space to keep the analog stuff and massive connectors.

I am using Raspberry Pi Zero 2W as the computer. Firstly I wanted to use something more powerful to be able to run ai smoother, like allwinner cubie a7z, but it is more expensive and the biggest issue is the firmware and gpio programming on this device. I have no idea, how I would programm this device, when there are basically no manuals or datasheets to this, so I am using the basic raspberry pi zero 2w. So the most interesting thing on this pcb is the pi zero 2w, which is connected to the board by set of pins and screw holes that can be mounted on the pcb by screws.

The drone itself would be able to lift off and fly to a location based on the gps, there is the barometer, from which the drone gets the current altitude and can get to ground. I am using walksnail camera and elrs, plus LIDAR. There is a jst connector for led strip, while at the same time there are built in leds on the drone chassis, esc unit connector and built in electromagnetic buzzer and boot and rst buttons.

The first stage was actually studying the STM32 pinouts and figuring out as much possible of how modern flight controllers handle gyro SPI communication and high speed SDIO routing.

A custom mainboard designed to replace standard generic flight controllers. Built to handle Betaflight high speed kinematics and communicate directly with a Raspberry Pi Zero 2W. Designed entirely from scratch in KiCad 10.

Project Features

• Microcontroller: STM32F405 (100-pin, 32-bit ARM Cortex-M4)
• Stackup: 4-Layer PCB (Signal / GND / GND+Power / Signal) for internal routing and better EMI shielding against switching inductors
• IMU (Gyro): TDK InvenSense ICM-42688-P connected via dedicated hardware SPI1 bus for high-speed kinematics
• Barometer: Goertek SPL06-007 on-board sensor for accurate altitude telemetry
• Power: VBAT main input with robust 5V switching regulator (TPS54302) and isolated 3.3V sensor rails
• Connectivity: USB-C for main communication with USBLC6 ESD protection, native Raspberry Pi UART interface
• Digital Video: Dedicated Walksnail/Caddx VTX JST-SH port (Analog OSD intentionally removed to save space)
• Storage: Integrated MicroSD slot (Hirose Push-Pull) routed via high-speed 4-bit SDIO bus for blackbox logging
• Hardware Protections: Strict 1:1 hardware pin layout for GPS and LiDAR connectors to prevent accidental voltage shorts during assembly
• Radio Link: Dedicated UART port for 2.4GHz ExpressLRS nano receiver.

Firmware

Since this board is built around a custom STM32F405 microcontroller, it runs on the open-source Betaflight firmware. Instead of writing custom flight control loops from scratch, the firmware setup uses a custom target configuration. You can find the complete pin-mapping and resource file (AeroZero_BF_Config.txt) ready in the Firmware folder.

Gallery

3D PCB Render

PCB

Schematics

Mechanical Integration MARK4

Mechanical Integration CUSTOM AERO-ZERO CAD

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Bill of Materials (BOM)