Is Matek F722-SE the best flight controller of 2018? Perhaps it's "slightly" too early for such statements, but for sure, it looks like one of the strongest pretenders for such a title (if the title existed).
In a meantime, a video showing brand new Matek F722-SE flight controller and most of its features.
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!
When Banggood decided to “forget” about MS5611barometer in their version of AnyFC F7 flight controller, they not only did not mounted MS5611 on it. They also made usage of any external barometer on that board almost impossible to use.
Why? Long story short: all STM32 MultiWii derivatives are unable (yet) to lookup for I2C devices across different I2C buses. So, if we define barometer to be connected to I2C bus #4, firmware will look to barometers only on I2C bus #4. But, since many boards uses multiple I2C buses, this creates a problem: AnyFC F7 onboard (and missing) MS5611 is connected to I2C bus #4, but I2C bus available on JST connector in I2C bus #2.
While for Betaflight this is not a problem (BF pilots rather do not use barometer), it is a problem for INAV. AnyFC F7 target is unable to use any barometer if onboard MS5611 barometer is missing. OK, you can just solder one in place, but without hot air station and decent soldering skills this is not a good idea after all. This is why, until better solution is found, INAV will include ANYFCF7_EXTERNAL_BARO target. The only difference between ANYFCF7 and ANYFCF7_EXTERNAL_BARO is barometer support.
If you have MS5611 in place (soldered in or bought with one) or do not intend to use any baro, you should use ANYFCF7 target.
When you do not have onboard MS5611 and want to use external barometer (MS5611, BMP180/085 or BMP280) you should use ANYFCF7 and ANYFCF7_EXTERNAL_BARO target.
Until new official version of INAV is published, you might use this custom hex: INAV_1.7.1_ANYFCF7_EXTERNAL_BARO.hex. It is based on INAV 1.7.1 and proven to detect external barometers via JST connector.
AnyFC F7 when running INAV, is not using standard output mapping. That means, that M1 output is not where you should connect Motor 1 and M2 is not where Motor 2 should be connected. It’s a little complicated, but with following table it should be pretty easy to connect any possible configuration to AnyFC F7 and INAV.
There is still very little about AnyFC F7 on the internet. Especially pinout is kept secret. Without sambas official GitHub repository for hardware projects, there would be nothing at all. I’ve decided to close that gap a little and prepared full pinout for AnyFCF7.
Yes, I know they are hand drawn and scanned, but I have a strong aversion for computer graphics software. I can move a slider left and right, but every time I have to do some creative photoshopping, my head starts to hurt. This is extremely ironic, since my major at university was computer graphics. Heh…
STM32F7 CPU family present in newest, experimental, flight controllers like AnyFC F7 (as well as upcoming AnyFC M7 with smaller STM32F722) simplifies many things. For example, comparing to F4 boards, SmartPort or S.Bus connection is extremely simple and can be done on any free UART. No more hardware hacks, external inverters and other “special” ways of doing things.
It’s super simple again, and here is how to do it in Betaflight (Cleanflight 2.x) and INAV
The only required hardware is a cable to connect SmartPort enabled receiver with free UART port on F7 board. This will work on X8R, X6R, X4R, X4RSB, XSR and any other. The trick is to connect S.Port pin with UART TX pin only.
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.