import machine
adc = machine.ADC() # create an ADC object
apin = adc.channel(pin='P16') # create an analog pin on P16
val = apin() # read an analog value
Create an ADC object; associate a channel with a pin. For more info check the hardware section.
Enable the ADC block. This method is automatically called on object creation.
bits
can take values between 9 and 12 and selects the number of bits of resolution of the ADC block.Disable the ADC block.
Create an analog pin.
pin
is a keyword-only string argument. Valid pins are P13
to P20
.attn
is the attenuation level. The supported values are: ADC.ATTN_0DB
, ADC.ATTN_2_5DB
, ADC.ATTN_6DB
, ADC.ATTN_11DB
Returns an instance of ADCChannel
.
If called without any arguments, this function returns the current calibrated voltage (in millivolts) of the 1.1v
reference. Otherwise it will update the calibrated value (in millivolts) of the internal 1.1v
reference.
Connects the internal 1.1v
to external GPIO
. It can only be connected to P22
, P21
or P6
. It is recommended to only use P6
on the WiPy, on other modules this pin is connected to the radio.
ADC.ATTN_0DB
: 0dB attenuation. 1V will be registered as 1VADC.ATTN_2_5DB
: 2.5dB attenuation. 1V will be registered as 0.75VADC.ATTN_6DB
: 6dB attenuation. 1V will be registered as 0.5VADC.ATTN_11DB
: 11dB attenuation. 1V will be registered as 0.3VNote: The voltages will automatically be corrected by
adcchannel.voltage()
The following methods can be applied on the adcchannel()
instance. ADC channels are created using the ADC.channel(...)
method.
Fast method to read the channel value.
Read the channel value.
(Re)init and enable the ADC channel. This method is automatically called on object creation.
Disable the ADC channel.
Reads the channels value and converts it into a voltage (in millivolts)
Converts the provided value into a voltage (in millivolts) in the same way voltage does.
ADC pin input range is
0-1.1V
. This maximum value can be increased up to3.3V
using the highest attenuation of11dB
. Do not exceed the maximum of 3.3V, to avoid damaging the device.