Battery percentage measurement in nrf connect SDK

[Pranathi CH]

Hi Nordic,

I am exploring on how to use an ADC module for measuring the battery percentage for my nrf52840. I am working on the nrf connect SDK. Can anyone suggest me a sample for reading the battery percentage in the zephyr SDK?

Thanks,

Pranathi

[Sigurd Hellesvik]

Hi,

See Battery Voltage Measurement sample

Regards,
Sigurd Hellesvik

[Pranathi CH]

Hi Sigurd,

I can see the board compatibilities for the battery sample is only for partical_xenon and thingy52_nrf52832 but I only have nrf 52833 dk with me right now, So I tried to build with that configurations and faced errors..

Can you suggest me any sample that could be built for ntf52833 dk?

Thanks,

Pranathi

[Pranathi CH]

Hi Sigurd,

I did change the build configuration for the battery sample with nrf52833dk_nrf52833 and I got the build errors as such:

• '__device_dts_ord_DT_N_S_zephyr_user_P_io_channels_IDX_0_PH_ORD' undeclared here (not in a function)
• 'DT_N_S_zephyr_user_P_io_channels_IDX_0_VAL_input' undeclared here (not in a function)
• identifier "DT_N_S_zephyr_user_P_io_channels_IDX_0_VAL_input" is undefined
• identifier "__device_dts_ord_DT_N_S_zephyr_user_P_io_channels_IDX_0_PH_ORD" is undefined

Thanks,

Pranathi

[Sigurd Hellesvik]

Which changes did you make to the sample?

[Pranathi CH]

I changed the build configuration for nrf52833 as the compatible build for it is partical_xenon and thingy52_nrf52832, I did not get any errors while building the battery sample for these two but I faced issues when I build the project with nrf52833dk_nrf52833 build configuration.

[Sigurd Hellesvik]

Have you added a vbatt node with voltage-divider as described in the sample documentation, and have you specified the A0 pin there? See Battery Voltage Measurement sample documentation for details.

[Pranathi CH]

Yeah I have added the vabtt node in by dts file and still getting errors and how & where do I specify the A0 pin I could not find about it in the link?

Sigurd Hellesvik said:

Battery Voltage Measurement sample documentation

[Sigurd Hellesvik]

From the docs, I added this to the sample as an overlay:

/ {
   vbatt {
      compatible = "voltage-divider";
      io-channels = <&adc 4>;
      output-ohms = <180000>;
      full-ohms = <(1500000 + 180000)>;
      power-gpios = <&gpio0 4 0>;
   };
   zephyr,user {
      io-channels = <&adc 4>;
   };
};

Our nRF52840DK does not have a voltage divider to measure the power, so you will have to add this yourself and configure the overlay accordingly