HardwareSerial U(S)ART RX/TX level inversion for F407

[heretop]

Hi,

I want to add inversion to the RX pin of F407 U(S)ART. There is similar thing added to HardwareSerial for F3 and F7 https://github.com/stm32duino/Arduino_C ... -995889715. But it is not possible for F4. May I know is there any way to do this besides the hardware way like add a hardware inverter ic? I am working on a design with very limited size.

Thanks a lot!

[ag123]

invert the data before sending?