Hi,
I have a custom cape designed for BBB with Modbus RTU. It was using UART4 pins P9.11, P9.13, P9.27 (Rx, Tx & RTS). Now on the BeagleBone AI64 these pins are UART0. Is it possible to use these pins?
If that’s not possible I want to use UART3 pins, how to write the devicetree for it?
I tried writing my own overlay and ended up bricking the board. Had to reflash a new OS.
Its best to boot from SD card when working on device trees or other critical stuff.
If you break the system you can mount the SD card with your dev box and edit to remove the over lay. Typically they just don’t load, you must have the node mis-configured and it is a conflict with existing resources since it did break the os. Once your target is configured and stable go back and flash your SD card to emmc.
Ti is a mess to work with, they even shut off saveenv in uboot so you cannot load a device tree that way. You have to mess around building a new ti3boot and some other changes. Spend hours trying to find all the roadblocks they have installed in their bsp.
At this point, it is down to using the factory BB image on SD card and if they have an overlay for that UART3 then you are good to go. Otherwise, not so good.