Hands on: AnyFC F7 from Banggood

Before we proceed, short clarification. Legal background of AnyFC F7 flight controller from Banggood is iffy. It’s not that BG ripped the design from Sami Korhonen (sambas). Sambas published design of his AnyFC under Creative Commons BY-SA. So, it’s free to copy this design as long as Sambas is referenced as author, and license is not changed. The problem is that “by attribution” part is not met. Sambas is not referenced as author on BG. Still, Sami wrote that he is fine with it, as long as boards quality is good enough.

Today I have something brand new to write about. Probably the first commercially available flight controller based on STM32F7 CPU: AnyFC F7 from Banggood.

AnyFC F7 STM32F745 flight controller

Why STM32F7? Do we need all that computational power that comes with F7 on a flight controllers? After all, F7 is fast enough to decode H.264 and runs on 216MHz. The answer is: no. We do not need all that computational power. We need something else: hardware inverters and IO flexibility. STM32F4 CPU that powers most FC right now, are older designs than STM32F3 and comparing to STM32F3 they lacks IO flexibility and hardware inverters on UART ports. F7 combines best of those two: IO subsystem “from F3” and raw power of F4. If to think about it, they are better choice than F4.

AnyFC F7 comes with following features:

  • Supported by Betaflight and INAV (from upcoming 1.7)
  • Comes flashed with Betaflight 3.1.6
  • STM32F745VGT6 100lqfp at 216MHz
  • MPU6000 IMU connected via SPI bus
  • 8 (eight) UART ports and VCP port AnyFC F7 8 UART ports
  • I2C bus
  • CAN bus
  • external SPI bus (pins shared with UART4 and UART5)
  • SD card slot for blackbox logs
  • 10 PWM outputs
  • 6 PWM inputs (inputs 3 and 4 shared with UART6)
  • 3 analog (ADC) inputs: ADC0 with 1kOhm/10kOhm voltage divider, ADC1 and ADC2 with 1kOhm inline resistors
  • SBUS available on any UART without any additional inverters
  • SmartPort telemetry on any UART without any additional inverters or hardware hacks. Just connect TX line to SmartPort and done! (I will have to test that)

AnyFC F7 STM32F745 flight controller

AnyFC F7 running Betaflight

AnyFC F7 running INAV 1.7 RC1

AnyFC F7 is probably the first commercial F7 FC, and as a first design it has few problems:

  • There is no dedicated buzzer port. More that that: there is no buzzer support on AnyFC F7 at all in both Betaflight and INAV
  • BOOT pad is well… hard to use, since it’s only a pad with some solder on it
  • Documentation is non existent
  • There are pads for MS5611 baro, but baro itself is missing. According to Sambas, all traces are fine, and if one has enough skills, MS5611 baro can be soldered directly to them
  • I would gladly sacrifice one or 2 UARTs for OSD
  • BG clone has some SD Card problems: firmware is unable to detect missing SD card since carddetect pin is not cloned. But card logging should be functional
  • Not all features are fully supported in software. For example, INAV is missing performance improvements, so 2kHz looptime is still the limit

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