UART Pin Change with DTS Overlay

RE: UART Pin Change with DTS Overlay

SwRa — Tue, 06 Jun 2023 13:41:14 GMT

Hi Evan,

Are you using the 52-DK.? If you see the backside of the board, you can see the pins that are already in use.. So could you try with any other free gpio.?

Regards,

Swathy

RE: UART Pin Change with DTS Overlay

Evan Colt — Tue, 30 May 2023 15:17:02 GMT

Hi Swathy,

I am using a serial to USB cable outputting to a standard serial terminal (screen or Arduino). I do not see any errors with either version of the DTS file but when I use the default pins I am able to send and receive serial data and when I use my modified pins I am not so as you stated 'the expected output does not appear in the newly assigned pins'. Again the code is not logging any errors. I will experiment with this a little more later today to see if I can give you any more specific information.

RE: UART Pin Change with DTS Overlay

SwRa — Tue, 30 May 2023 10:58:27 GMT

Hi Evan,

How are you checking the outputs.? Did you use a logic analyzer to check the UART outputs after changing the pins.? By not working, is there any error message that shows up or only that the expected output does not appear in the newly assigned pins..? The overlay looks correct and I cannot see why this is not working.

Regards,

Swathy

RE: UART Pin Change with DTS Overlay

Evan Colt — Tue, 23 May 2023 16:26:16 GMT

Hi,

the pins for UART zero were assigned by default in the app-pinctrl.dtsi file as shown below

&pinctrl {
	uart0_default: uart0_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 6)>,
				<NRF_PSEL(UART_RX, 0, 8)>,
				<NRF_PSEL(UART_RTS, 0, 5)>,
				<NRF_PSEL(UART_CTS, 0, 7)>;
		};
	};

	uart0_sleep: uart0_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 6)>,
				<NRF_PSEL(UART_RX, 0, 8)>,
				<NRF_PSEL(UART_RTS, 0, 5)>,
				<NRF_PSEL(UART_CTS, 0, 7)>;
			low-power-enable;
		};
	};

This being said, these lines are faded becuase they are being overriden by the lines in my overlay file described above. I have also tried changing these lines directly without using an overlay and I encounter the same issue.

The only other place uart0 is defined is in the app.dts file but these line referece the pin control file to declare the pins as seen below:

arduino_serial: &uart0 {
	status = "okay";
	compatible = "nordic,nrf-uarte";
	current-speed = <115200>;
	pinctrl-0 = <&uart0_default>;
	pinctrl-1 = <&uart0_sleep>;
	pinctrl-names = "default", "sleep";
};

Let me know if I can provide any more info that my be relevant to this.

Thanks!

RE: UART Pin Change with DTS Overlay

SwRa — Tue, 23 May 2023 09:17:56 GMT

Hi Evan,

The overlay that you have shared looks correct. Could you check if uart0 has been defined in any other group within the dts file.?

Regards,

Swathy