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Analog-to-Digital Converter (ADC)

Overview

This sample demonstrates how to use the ADC driver API.

Depending on the MCU type, it reads the ADC samples of one or two ADC channels and prints the readings to the console. If supported by the driver, the raw readings are converted to millivolts.

The pins of the ADC channels are board-specific. Please refer to the board or MCU datasheet for further details.

Note

This sample does not work on Nordic platforms where there is a distinction between channel and analog input that requires additional configuration. See samples/boards/nrf/battery for an example of using the ADC infrastructure on Nordic hardware.

Building and Running

The ADC peripheral and pinmux is configured in the board’s .dts file. Make sure that the ADC is enabled (status = "okay";).

In addition to that, this sample requires an ADC channel specified in the io-channels property of the zephyr,user node. This is usually done with a devicetree overlay. The example overlay in the boards subdirectory for the ST Nucleo L073RZ can be easily adjusted for other boards.

Building and Running for ST Nucleo L073RZ

The sample can be built and executed for the ST Nucleo L073RZ as follows:

west build -b nucleo_l073rz samples/drivers/adc
west flash

To build for another board, change “nucleo_l073rz” above to that board’s name and provide a corresponding devicetree overlay.

Sample output

You should get a similar output as below, repeated every second:

ADC reading(s): 42 (raw)

Note

If the ADC is not supported, the output will be an error message.