ADC Error with NRF52832

[Thishon]

I have used ADC Channel 6 (P0.30) for voltage measurement using NRF52832. Previously It was working well. Now it is returning an error.

00> [00:00:00.398,345] <err> adc_nrfx_saadc: Selected ADC reference is not valid

This is where I have configured my adc parameters in the overlay file.

/ {

    zephyr,user {

        io-channels = <&adc 6>;

    };

};

&adc {
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
channel@6 {
reg = <6>;
zephyr,gain = "ADC_GAIN_1_6";
zephyr,reference = "ADC_REF_VDD_1";
zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
zephyr,input-positive = <NRF_SAADC_AIN6>; /* P0.02 for nRF52xx, P0.04 for nRF5340 */
zephyr,resolution = <12>;
};
};

[ssstik]

That error usually points to an invalid reference configuration in the device tree. For the nRF52832, ADC_REF_VDD_1 isn't a valid option — it's typically only available on some newer SoCs like nRF5340. Try switching the reference to ADC_REF_INTERNAL or simply omit the zephyr,reference property to use the default internal reference voltage (0.6V).

Also, double-check that NRF_SAADC_AIN6 (which maps to P0.30 on nRF52832) is correct and not being used by another peripheral like NFC or GPIO without proper configuration.

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Good luck debugging!