class ADC – analog to digital conversion

The ADC class provides an interface to analog-to-digital converters, and represents a single endpoint that can sample a continuous voltage and convert it to a discretised value.

For extra control over ADC sampling see machine.ADCBlock.

Example usage:

from machine import ADC

adc = ADC("PA3")        # create an ADC object acting on a pin
val = adc.read_u16()  # read a raw analog value in the range 0-65535

Constructors

class machine.ADC(id, *, sample_ns, atten)

Access the ADC associated with a source identified by id. This id may be an integer (usually specifying a channel number), a Pin object, or other value supported by the underlying machine.

If additional keyword-arguments are given then they will configure various aspects of the ADC. If not given, these settings will take previous or default values. The settings are:

• sample_ns is the sampling time in nanoseconds.

• atten specifies the input attenuation.

Methods

ADC.init(*, sample_ns, atten)

Apply the given settings to the ADC. Only those arguments that are specified will be changed. See the ADC constructor above for what the arguments are.

ADC.read_u16()

Take an analog reading and return an integer in the range 0-65535. The return value represents the raw reading taken by the ADC, scaled such that the minimum value is 0 and the maximum value is 65535.