Adding Extra UART to Omnibus F4 Pro by editing hwdef file to repurpose RSSI and PWM5

Following this RCGroups post I am trying to add an extra UART to my installed Omnibus F4 Pro V3.

RSSI and PWM5 can be repurposed by editing the hwdef file it seems.

These are the instruction the RCGroups poster offered:

In hwdef.dat add UART4
Finally remove the RSSI (ADC) and PWM5 definitions.

This looks nothing like the hwdef file I can find in my target folder. This file is a .h file while the poster makes reference to a .dat file. Am I looking in the correct place? Can anyone give me pointers?

This is the file you want

Many thanks Pete for that link. Should have known to look in Chibios HAL directory.

Hi, I know it’s been a long time since your question but could you tell me if it’s necessary to change the software code inorder to enable uart 4 or you can also do it with just putting BRD_ALT_CONFIG to 3 and nothing else at all in mission planner ?

Varies with targets. But to use the rssi pad as a uart tx or rx on this board I think you may need to edit the hwdef.dat file and recompile.

Ok so does it work well enough on your board after doing the code change or did you do both the code change as well as BRD_ALT_CONFIG parameter to some operable value inorder to get uart 4 to work out ?

And another thing, the reason I did not want to do the software code change is because I’m severely inexperienced with insides of mission planner so could you give me a heads up on how exactly you changed the hwdef.dat files and recompiled the software? please try to be as basic as possible while also not leaving any important info out.