u/Helpful_Training_378

Hello everybody,

I've been working on a UAV flight controller that I intend to run Ardupilot on.

You can find the Project here for the pin configuration on STM32CUBEMX here. And for BOM here.

Note: the Layout in the github file is not ready at all.

I tried to make the design as modular as possible, meaning that most of the job done on the FC is to distibute power to the modules (RF reciever, GPS etc.)

and control ESCs (Electronic speed controller) and Servo motors.

- MCU:

The MCU I selected is highly capable STM32H7 series with a 100 pins. I saw a lot of similar designs using It so I used it.

- Sensors:

I'm using a ICM-42688 IMU + Gyro and a MS5611 barometer and temperature sensor for altitude. Just like the MCU I saw lots of designs using It and the sensors are Ardupilot compatible, They're also available at local distributers and not too expensive, Although I'm considering the following for SPI lines:

1- Adding pull-up resistors to the SPI lines.

2- Adding series termination resistors.

3- Matching their length in the Layout.

I'd be very happy if you can provide articles, studies in regard of these topics.

- Connectors:

The connectors I'm using are not included in the BOM, because I haven't quite decided yet but I'm considering the following:
- JST-GH (1.25 mm pitch): for everything except for the RF tranciever and power connector.
- Molex Clik-Mate (2 mm pitch): for power and RF tranciever, particularly because it can handle higher currents.
-For the PWM and Dshot I'm considering plain pads that I'll solder some wires on. (btw pwm is used for the servo motors, and Dshot is for ESCs).
- For the SD card I'm also considering pull up resistors and length matching in the layout just like for the sensors.
- I'll be probably using a GPS + magnetometer module (something like the BN-880).

- Pitot tube, Reciever, RF tranciever, Aux Computer connection (sometimes an additional computer is used for image processing etc.) and LIDAR are all standard.
- I'm also considering adding termination resistors to the UART lines, the resistors you see are a result of me consulting Gemini and I'm not sure about them.

- Power:

For the power I want to be able to power the board both from a USB-c port and from a power connector, I'm considering powering the board from a pixhawk power module. I'm considering adding higher capacitance to the input as a DC-linkish.
I have two seperate 3.3V outputs, one from an LDO that will power the digital part of the board (SD-card, MCU VDD pins) and the LDO will power the analog part of the board (sensors, GPS module).

If you have any questions please ask. And I welcome any recommendation :).
This is my 3rd PCB btw.