IRNAS / irnas-voltage-divider-driver

irnas-voltage-divider-driver

This repository contains driver and basic test for voltage divider driver, based on Zephyr Battery Voltage Measurement sample. Driver uses Zephyr ADC infrastructure to measure the voltage of the device power supply.

IMPORTANT: This driver is only suitable for Nordic chips, like nrf52832, nrf52840 and so on. This is due to the chip specific way how adc channels are configured.

IMPORTANT: This driver hard codes adc gain, reference, acquisition_time, adc resolution and some other adc settings. This is done in driver/voltage_divider/voltage_divider.c in voltage_divider_sample function, see assignment of data->adc_seq and data->adc_cfg structs.

Usage

To use add below two snippets into your project's west.yml file and run `west update``:

1. In remotes section, if not already added:

- name: irnas
  url-base: https://github.com/irnas

2. In the projects section, select revision you need:

- name: irnas-voltage-divider-driver
   repo-path: irnas-voltage-divider-driver
   path: irnas/irnas-voltage-divider-driver
   remote: irnas
   revision: v2.0.0

Device tree

To enable this driver you need to add below snippet into your DTS or overlay file. For information on how to properly configure this driver see dts/bindings/irnas,voltage-divider.yaml

vbatt {
    compatible = "irnas,voltage-divider";
    io-channels = <&adc 1>;
    upper-resistor-ohms = <1000>;
    lower-resistor-ohms = <1000>;
    status = "okay";
};

Shell

This driver also implements a shell interface for interacting with the voltage divider device instance. To add it to your existing shell add below line into your Kconfig fragment file:

CONFIG_VOLTAGE_DIVIDER_SHELL=y