STM32F405 & AT32F435 Flight Controller for Betaflight firmware drones

Yes, you can use any of those CPU with the same board. AT32 is more powerful and cheap but Betaflight support is in early stages.

I hope you like and find value on the project, if you build it please, share it here!

The main idea of this project is to learn and play while designing a functional F4 Flight Controller compatible with Betaflight firmware.

Specs

• STM F405 or AT F435
• 6 UARTS
• MPU600 Gyro (also BMI and ICM)
• Blackbox, up to 128MB!
• 10v pad for DJI
• BMP280 Barometer
• OSD Support
• 3-6S voltage
• Buzzer pads
• SDA/SCL for GPS reconfiguring UART3

It has been tested with both CPUs!

Be aware that UART3 and UART2 connected peripherals may avoid the connection when in DFU mode. This is really common on many the FCs but manufactures usually does not make it public.

• UART3 with RX or GPS are prone to this, if it happens to you, desolder it temporarily. 
• UART2 should be less than an issue as is mostly reserved for ESC and no devices should be connected.

This will only affect when enabling DFU mode and some peripherals are on those ports, not all peripherals will be an issue. Use first any of the other 4 UARTS available if possible.

How to load Betaflight

AUTOMATIC

Betaflight now officially has the target for this board available

STM32F405 Chip

• Betaflight 4.5
• Download Betaflight repo and compile the firmware for the next target file 
• Acci FC - Target files (github.com)
• Betaflight < 4.5
• Download Betaflight configurator 10.8 and flash the firmware version you prefer of the target STM32F405.
• Once the firmware is loaded connect and enter cli to load the board configuration
• Acci FC - Target files (github.com)

AT32F435 Chip

• Betaflight 4.5
• Download Betaflight repo and compile the firmware for the next target file
• Acci FC - Target files (github.com)

All the targets can be found here: Acci FC - Target files (github.com)