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7 years, 8 months ago.
How to set an input pin as inverted on an STM32 F767ZI
How do I set an input to be inverted on an STM32 F767ZI. I want to use Futabas SBUS as an input but it is inverted. How do I set up input pin to invert the input ?
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I have not worked with this before, but a quick glance says the sbus stuff sends serial data to the uart on the microcontroller. This library uses Modserial, for example.
https://developer.mbed.org/users/Digixx/code/FutabaSBUS/
The inverted output seems to be common. The best thing to do is fix the hardware signal so it no longer inverted before going into the mbed board. There is probably a driver IC on the sender board doing the inverting, so you can try to grab the signal before it goes into that chip. Or you can build a little inverter adapter before sending the signal into the mbed board. Check the voltage levels of the sbus signal, they might be boosting the voltage output.
I believe the only option inside of mbed would be a soft serial port...i.e. bit banging. Often frowned upon of course. https://developer.mbed.org/users/Sissors/code/SoftSerial/
posted by Graham S. 25 Mar 2017ST F3 boards have hardware inverters on the inputs to enable, it looks like F7 boards don't.
posted by David Fisher 26 Mar 2017