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| -rw-r--r-- | docs/rp2/quickref.rst | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/docs/rp2/quickref.rst b/docs/rp2/quickref.rst index 11a808c110..ecf3f31861 100644 --- a/docs/rp2/quickref.rst +++ b/docs/rp2/quickref.rst @@ -187,6 +187,14 @@ Use the :ref:`machine.ADC <machine.ADC>` class:: adc = ADC(Pin(26)) # create ADC object on ADC pin adc.read_u16() # read value, 0-65535 across voltage range 0.0v - 3.3v +The argument of the constructor ADC specifies either a Pin by number, name of as +Pin object, or a channel number in the range 0 - 3 or ADC.CORE_TEMP for the +internal temperature sensor. If a pin is specified, +the pin is initialized in high-Z mode. If a channel number is used, the pin +is not initialized and configuring is left to the user code. After hard reset, +RP2040 pins operate in current sink mode at about 60µA. If the pin is not +otherwise configured, that may lead to wrong ADC readings. + Software SPI bus ---------------- |