Hands on: Omnibus F7 Flight Controller

Thanks to Airbot I got my hands on a new STM32 F7 flight controller: Omnibus F7.

Before we proceed, small note.

I am a huge fan of F7 flight controllers. In a year, they will be a main line of high performance FC on the market. STM32F7 with built-in UART inverters solves so many issues STM32 F4 boards are facing. But, F7 are not there yet. Currently available boards uses STM32F745 CPU in 100 pin packages. They are just too big to comfortably fit 36x36mm format. You place CPU and most of the PCB is taken. Than means there is no space left for either connectors or OSD for example. What we are waiting are FC with STM32F722 in 64pin package!

Omnibus F7 flight controller top view

First thing you will notice while looking at this board is a huge CPU in the middle. Yea baby, F7. But if you look more closely, you will notice something else. This board has two gyroscopes! It has beloved MPU6000, but also a ICM-20608-G which is a newer version of MPU6500. One might say YAY, twice the fun. Unfortunately, not so much. Problem with 2 gyroscopes is that current software can not make use of it. Betaflight can only choose if you want to use this or than, but that is all. No gyro fusion, no redundancy. There are potential perks of having two gyros, but it will take a long long time for flight controller software (BF, INAV, CF) to make use of it. Right now is only a feature.

Also, on the moment of writing it, only not-yet-published Betaflight 3.2 supports this board. And it still struggles with some problems, so according to one of Betaflight developers, it's not advised to fly it yet with Multishot protocol. It should be OK with OneShot125 and DShot, but Multishot is not advised.

Omnibus F7 flight controller bottom view

Another problem is rather "limited" number of outputs comparing to what CPU offers. Remember? 100 pin package but only 4 PWM outputs (4 motors), 3 UARTs or 2 UARTs and I2C plus SPI you can not yet really use? This is fine for a racer, but not so cool on bigger UAVs…

OK, so maybe this is not the best designed flight controller ever. But, I'm very very happy it was created. It's another small step for future F7 boards that will come. Everyone will learn something from this board. And maybe this is what pilots really need? Hard to decide. I will not yet put this on any of my quads. First I want to add this board to INAV and then either use it on my GPS Racer project or put on regular racer. So I'm not yet putting any label on this board yet. Give me some time 🙂

Omnibus F7 features

  • STM32F745 CPU
  • Dual gyro system: MPU6000 and ICM-20608-G, current firmware (Betaflight 3.2 allows only to choose one of them, no sensor fusion or redundancy)
  • 3 UART ports available to user: UART1, UART3 and UART6
  • I2C port shared with UART3
  • PPM/SBUS port connected to UART2 RX, so PPM does not blocks user available ports. This is not yet implemented in Betaflight, time will show how it will evolve… Looks like any other UART has to be used for Sbus
  • 4 PWM outputs (4 motors)
  • Integrated 1A switching BEC
  • Integrated OSD
  • SD Card slot for Blackbox data
  • LED Strip and buzzer support

Omnibus F7 pinout

Omnibus F7 pinout

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