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Remove redundant unit from definition of HIGH level #840

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Jun 26, 2021
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Remove redundant unit from definition of HIGH level #840

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2 changes: 1 addition & 1 deletion Language/Variables/Constants/constants.adoc
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Expand Up @@ -41,7 +41,7 @@ When reading or writing to a digital pin there are only two possible values a pi
The meaning of `HIGH` (in reference to a pin) is somewhat different depending on whether a pin is set to an `INPUT` or `OUTPUT`. When a pin is configured as an `INPUT` with `link:../../../functions/digital-io/pinmode[pinMode()]`, and read with `link:../../../functions/digital-io/digitalread[digitalRead()]`, the Arduino (ATmega) will report `HIGH` if:

- a voltage greater than 3.0V is present at the pin (5V boards)
- a voltage greater than 2.0V volts is present at the pin (3.3V boards)
- a voltage greater than 2.0V is present at the pin (3.3V boards)
[%hardbreaks]

A pin may also be configured as an INPUT with link:../../../functions/digital-io/pinmode[`pinMode()`], and subsequently made HIGH with `link:../../../functions/digital-io/digitalwrite[digitalWrite()]`. This will enable the internal 20K pullup resistors, which will _pull up_ the input pin to a `HIGH` reading unless it is pulled `LOW` by external circuitry. This can be done alternatively by passing `INPUT_PULLUP` as argument to the link:../../../functions/digital-io/pinmode[`pinMode()`] function, as explained in more detail in the section "Defining Digital Pins modes: INPUT, INPUT_PULLUP, and OUTPUT" further below.
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