Cannot use UART1

[Nedaa_H_Ahmed]

Hello, I cannot use UART1, and I don`t know the reason for that.
I run the exercise: https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/lessons/lesson-4-serial-communication-uart/topic/exercise-1-5/

using UART0, and it works fine. When I replaced UART0 with UART1, I could not receive or transmit any data.
The overlay, the prj.conf, and the output in case UART1 are attached.

I am using NCS version 2.9.0

This is the output in case UART1 and the LEDs didn`t toggle.

This is the prj.conf file:

Here is the overlay file:

[Turbo J]

Look at the generated dts in build/zephyr - UART1 has none of the pinctrl stuff IIRC. You also need to disable all conflicting shared peripherials (TWI/SPI) in the dts overlay.

[Nedaa_H_Ahmed]

1145.devicetree_generated.h

Here is the generated device tree file. Could you please tell me the lines of pinctrl that exist for uart0, not uart1?

I thought uart1 assigned pinctrl as the nrf52840dk_nrf52840.dts file contains this configuration for uart1

arduino_serial: &uart1 {

    current-speed = <115200>;

    pinctrl-0 = <&uart1_default>;

    pinctrl-1 = <&uart1_sleep>;

    pinctrl-names = "default", "sleep";

};

and the nrf52840dk_nrf52840-pinctrl.dtsi contains this configuration for uart1_default and uart1_sleep

uart1_default: uart1_default {

        group1 {

            psels = <NRF_PSEL(UART_RX, 1, 1)>;

            bias-pull-up;

        };

        group2 {

            psels = <NRF_PSEL(UART_TX, 1, 2)>;

        };

    };

    uart1_sleep: uart1_sleep {

        group1 {

            psels = <NRF_PSEL(UART_RX, 1, 1)>,

                <NRF_PSEL(UART_TX, 1, 2)>;

            low-power-enable;

        };

    };

[Marte Myrvold]

Hi,

UART0 is defined on lines 7-27 in nrf52840dk_nrf52840-pinctrl.dtsi:

uart0_default: uart0_default {
	group1 {
		psels = <NRF_PSEL(UART_TX, 0, 6)>,
			<NRF_PSEL(UART_RTS, 0, 5)>;
	};
	group2 {
		psels = <NRF_PSEL(UART_RX, 0, 8)>,
			<NRF_PSEL(UART_CTS, 0, 7)>;
		bias-pull-up;
	};
};

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;
	};
};

While UART1 is defined on lines 21-45 of the same file:

uart1_default: uart1_default {
	group1 {
		psels = <NRF_PSEL(UART_RX, 1, 1)>;
		bias-pull-up;
	};
	group2 {
		psels = <NRF_PSEL(UART_TX, 1, 2)>;
	};
};

uart1_sleep: uart1_sleep {
	group1 {
		psels = <NRF_PSEL(UART_RX, 1, 1)>,
			<NRF_PSEL(UART_TX, 1, 2)>;
		low-power-enable;
	};
};

Best regards,
Marte

[Nedaa_H_Ahmed]

Thank you for your response.
Is there anything in the definition of the uart1 that prevents it from working?

[Marte Myrvold]

Hi,

Can you clarify what you mean or what the problem is?

There is nothing in UART1's definition that should prevent it from working.

Best regards,
Marte

[Nedaa_H_Ahmed]

When I used uart1 rather than uart0, I couldn`t receiver nor transmit any data

[Marte Myrvold]

Hi,

What do you have connected to the other end of the UART to receive or transmit data? Have you connected the GPIOs of UART1 to something?

Best regards,
Marte