92 lines
2.9 KiB
ReStructuredText
92 lines
2.9 KiB
ReStructuredText
.. _pyb.ADC:
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class ADC -- analog to digital conversion: read analog values on a pin
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======================================================================
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.. only:: port_pyboard
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Usage::
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import pyb
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adc = pyb.ADC(pin) # create an analog object from a pin
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val = adc.read() # read an analog value
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adc = pyb.ADCAll(resolution) # creale an ADCAll object
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val = adc.read_channel(channel) # read the given channel
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val = adc.read_core_temp() # read MCU temperature
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val = adc.read_core_vbat() # read MCU VBAT
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val = adc.read_core_vref() # read MCU VREF
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.. only:: port_wipy
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Usage::
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import pyb
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adc = pyb.ADC(channel) # create an analog object on one of the 4 ADC channels
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val = adc.read() # read an analog value
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Constructors
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------------
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.. only:: port_pyboard
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.. class:: pyb.ADC(pin)
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Create an ADC object associated with the given pin.
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This allows you to then read analog values on that pin.
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.. only:: port_wipy
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.. class:: pyb.ADC(channel)
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Create an ADC object on the given channel. Each channel is associated
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to a specific pin. For more info check the `pinout and alternate functions
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table. <https://raw.githubusercontent.com/wipy/wipy/master/docs/PinOUT.png>`_
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This allows you to then read analog values on that pin.
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.. warning::
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ADC pin input range is 0-1.4V (being 1.8V the absolute maximum that it
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can withstand). When GPIO2, GPIO3, GPIO4 or GPIO5 are remapped to the
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ADC block, 1.8 V is the maximum. If these pins are used in digital mode,
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then the maximum allowed input is 3.6V.
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Methods
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-------
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.. method:: adc.read()
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Read the value on the analog pin and return it. The returned value
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will be between 0 and 4095.
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.. only:: port_pyboard
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.. method:: adc.read_timed(buf, freq)
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Read analog values into the given buffer at the given frequency. Buffer
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can be bytearray or array.array for example. If a buffer with 8-bit elements
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is used, sample resolution will be reduced to 8 bits.
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Example::
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adc = pyb.ADC(pyb.Pin.board.X19) # create an ADC on pin X19
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buf = bytearray(100) # create a buffer of 100 bytes
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adc.read_timed(buf, 10) # read analog values into buf at 10Hz
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# this will take 10 seconds to finish
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for val in buf: # loop over all values
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print(val) # print the value out
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This function does not allocate any memory.
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.. only:: port_wipy
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.. method:: adc.enable()
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Enable the ADC channel.
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.. method:: adc.disable()
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Disable the ADC channel.
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