Merge pull request #710 from dotancohen/patch-1

Remove word that was incorrectly repeated twice.

Author: per1234

Language/Variables/Constants/constants.adoc

@@ -74,7 +74,7 @@ Digital pins can be used as `INPUT`, `INPUT_PULLUP`, or `OUTPUT`. Changing a pin
 Arduino (ATmega) pins configured as `INPUT` with link:../../../functions/digital-io/pinmode[`pinMode()`] are said to be in a _high-impedance_ state. Pins configured as `INPUT` make extremely small demands on the circuit that they are sampling, equivalent to a series resistor of 100 Megohms in front of the pin. This makes them useful for reading a sensor.
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-If you have your pin configured as an `INPUT`, and are reading a switch, when the switch is in the open state the input pin will be "floating", resulting in unpredictable results. In order to assure a proper reading when the switch is open, a pull-up or pull-down resistor must be used. The purpose of this resistor is to pull the pin to a known state when the switch is open. A 10 K ohm resistor is usually chosen, as it is a low enough value to reliably prevent a floating input, and at the same time a high enough value to not not draw too much current when the switch is closed. See the http://arduino.cc/en/Tutorial/DigitalReadSerial[Digital Read Serial^] tutorial for more information.
+If you have your pin configured as an `INPUT`, and are reading a switch, when the switch is in the open state the input pin will be "floating", resulting in unpredictable results. In order to assure a proper reading when the switch is open, a pull-up or pull-down resistor must be used. The purpose of this resistor is to pull the pin to a known state when the switch is open. A 10 K ohm resistor is usually chosen, as it is a low enough value to reliably prevent a floating input, and at the same time a high enough value to not draw too much current when the switch is closed. See the http://arduino.cc/en/Tutorial/DigitalReadSerial[Digital Read Serial^] tutorial for more information.
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 If a pull-down resistor is used, the input pin will be `LOW` when the switch is open and `HIGH` when the switch is closed.