Interfacing (DSI, CSI, I2C, etc.) • How to change RTS pin in CM5 overlay file

Hi,

I want to control a ISL32455EIBZ-T half-duplex RS485 transceiver via my CM5.

This is my schematic layout:According to the CM5 datasheet Uart0 should be GPIO14/15, which I used correctly, and GPIO 16/17 for ctsrts. This is where my problem is. I was stupid enough to simply connect GPIO25 on the PCB to the transceiver. RE/DE on the transceiver are also pulled low via a pull-down resistor, such that the transceiver is in receive mode.

I need to find a solution to override the existing Raspberry Uart0 config, such that I can declare GPIO25 as RTS. I believe I do not need to use CTS in this case.

I already found the specific overlay https://github.com/raspberrypi/linux/bl ... verlay.dts, but I don´t know how to simply change the pin in the overlay to the desired one.

Moreover, I believe I need to disable bluetooth first, as pinctrl gives me:at the moment.

Any ideas on how to change the RTS pin?

Thanks,
Nils

Statistics: Posted by Nils1234 — Tue May 13, 2025 3:46 pm — Replies 1 — Views 56

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