Please see responses below.
@daniel said in FC2 schematic and board file:
what is the purpose of STM32 UART7 through level shifters (74LVCH2T45)? both VCCA and VCCB are same 3.3V domain?
Yes, an early proto-type design had that port at 5V, so we had the level shifters. We then changed it to 3.3V for our production version, so technically the level shifters would not be needed, but it will give you longer cable drive range because of it.
J2 - where is VPP_STM connect to and what is the function?
You can get this info from any STM device spec. We (a programmer device) use it the way STM specifies
J5 - why there is no level shifter on UART5?
It is not needed. See response above.
J13 - Is that PM monitoring really need for FC? Can I just use a adc pin to monitor battery voltage through the divided resistors?
That feature is your choice. The power monitoring will be MUCH more accurate since we use a 16-bit device as highlighted here https://docs.modalai.com/power-module-v3-datasheet/ , and it is capable of coulomb counting if the PX4 drivers that can do that. There are tons of research articles out there about pure voltage monitoring vs coulomb counting, so we leave it to you to decide what works best for you.
RGB1 LEDs are controlled by GPO PE3/4/5, please confirm which pin for witch color.
We go in order of the port pins noted as "RGB", so PE3 is RED, PE4 is GREEN, PE5 is BLUE. All are "Active LOW" to Illuminate the LEDs.
Hope this helped!!
To me, based on all the questions you've been asking these past weeks, it seems as if you are designing your own version of HW that you want to be compatible with our FCv2 firmware.
If this is true, just let us know and we can try to assist you better. If you want a different form-factor for the board, that might be something we'd be interested in supporting if it helps you better. Just ask!
Feel free to use our contact page if you want the conversation to be less public: https://www.modalai.com/pages/contact-us