class ADC – analog to digital conversion¶
import pyb adc = pyb.ADC(pin) # create an analog object from a pin val = adc.read() # read an analog value adc = pyb.ADCAll(resolution) # creale an ADCAll object val = adc.read_channel(channel) # read the given channel val = adc.read_core_temp() # read MCU temperature val = adc.read_core_vbat() # read MCU VBAT val = adc.read_core_vref() # read MCU VREF
Create an ADC object associated with the given pin. This allows you to then read analog values on that pin.
Read the value on the analog pin and return it. The returned value will be between 0 and 4095.
Read analog values into
bufat a rate set by the
bufcan be bytearray or array.array for example. The ADC values have 12-bit resolution and are stored directly into
bufif its element size is 16 bits or greater. If
bufhas only 8-bit elements (eg a bytearray) then the sample resolution will be reduced to 8 bits.
timershould be a Timer object, and a sample is read each time the timer triggers. The timer must already be initialised and running at the desired sampling frequency.
To support previous behaviour of this function,
timercan also be an integer which specifies the frequency (in Hz) to sample at. In this case Timer(6) will be automatically configured to run at the given frequency.
Example using a Timer object (preferred way):
adc = pyb.ADC(pyb.Pin.board.X19) # create an ADC on pin X19 tim = pyb.Timer(6, freq=10) # create a timer running at 10Hz buf = bytearray(100) # creat a buffer to store the samples adc.read_timed(buf, tim) # sample 100 values, taking 10s
Example using an integer for the frequency:
adc = pyb.ADC(pyb.Pin.board.X19) # create an ADC on pin X19 buf = bytearray(100) # create a buffer of 100 bytes adc.read_timed(buf, 10) # read analog values into buf at 10Hz # this will take 10 seconds to finish for val in buf: # loop over all values print(val) # print the value out
This function does not allocate any memory.