One PWM output pin initializes high while the other 2 initialize low

RE: One PWM output pin initializes high while the other 2 initialize low

Dave Littell — Fri, 12 Dec 2025 14:48:44 GMT

Thanks, but explicitly getting rid of the "nordic,invert" with a "/delete-property/" fixed it. Having to undo stuff like this from the DK DTS has wasted some significant time (and keeps popping up as we progress). I'd request that you guys offer the option of starting with a clean DTS with none of the DK-specific stuff instead of forcing developers to create their own and spend time bludgeoning it into submission. ;-)

RE: One PWM output pin initializes high while the other 2 initialize low

Kazi Afroza Sultana — Fri, 12 Dec 2025 10:26:02 GMT

you can add this ''PWM_POLARITY_NORMAL'' for each of your pwm instances in the overlay file.

pwmheaters {
	compatible = "pwm-leds";

	pwm0_channel0: pwm0_channel0 {
		pwms = <&pwm0 0 PWM_MSEC(100) PWM_POLARITY_NORMAL>;
	};

	pwm1_channel0: pwm1_channel0 {
		pwms = <&pwm1 0 PWM_MSEC(100) PWM_POLARITY_NORMAL>;
	};

	pwm2_channel0: pwm2_channel0 {
		pwms = <&pwm2 0 PWM_MSEC(100) PWM_POLARITY_NORMAL>;
	};
};

To get a clean DTS for the nRF52840 you have to create your own out‑of‑tree board based on nRF52840 and customize its BOARD.dts and pinctrl files. You can read this here https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-3-adding-custom-board-support/.

RE: One PWM output pin initializes high while the other 2 initialize low

Kazi Afroza Sultana — Fri, 12 Dec 2025 10:12:21 GMT

Hello,

Can you try this (using a “sleep” state with low-power-enable) for the pinctrl of pwm0?

&pinctrl {
    pwm0_default: pwm0_default {
        group1 {
            psels = <NRF_PSEL(PWM_OUT0, 1, 15)>;
        };
    };

    pwm0_sleep: pwm0_sleep {
        group1 {
            psels = <NRF_PSEL(PWM_OUT0, 1, 15)>;
            low-power-enable;
        };
    };
};

&pwm0 {
    status = "okay";
    pinctrl-0 = <&pwm0_default>;
    pinctrl-1 = <&pwm0_sleep>;
    pinctrl-names = "default", "sleep";
};

It may help to define low power state.

RE: One PWM output pin initializes high while the other 2 initialize low

Dave Littell — Tue, 09 Dec 2025 17:21:14 GMT

Resolution: somehow a "nordic,invert" crept into pwm0_default and required a "/delete-property/". This highlights the need for starting with a CLEAN DTS when creating an overlay for a custom board. Where can I get a clean DTS for the nRF52840?