From 2d429e75ce69e77f8c95490ac03881ec9aa0354a Mon Sep 17 00:00:00 2001 From: Marti Bolivar Date: Mon, 25 Oct 2010 21:15:28 -0400 Subject: arduino language reference nearing completion, properly CC-BY-SA 3.0 attributed --- source/arduino/analogreference.rst | 66 -------------------------------------- 1 file changed, 66 deletions(-) delete mode 100644 source/arduino/analogreference.rst (limited to 'source/arduino/analogreference.rst') diff --git a/source/arduino/analogreference.rst b/source/arduino/analogreference.rst deleted file mode 100644 index 9a25169..0000000 --- a/source/arduino/analogreference.rst +++ /dev/null @@ -1,66 +0,0 @@ -.. _arduino-analogreference: - -analogReference(type) -===================== - -Description ------------ - -Configures the reference voltage used for analog input (i.e. the -value used as the top of the input range). The options are: - - - - -- DEFAULT: the default analog reference of 5 volts (on 5V Arduino - boards) or 3.3 volts (on 3.3V Arduino boards) -- INTERNAL: an built-in reference, equal to 1.1 volts on the - ATmega168 or ATmega328 and 2.56 volts on the ATmega8. -- EXTERNAL: the voltage applied to the AREF pin is used as the - reference. - - - -Parameters ----------- - -type: which type of reference to use (DEFAULT, INTERNAL, or -EXTERNAL). - - - -Returns -------- - -None. - - - -Warning -------- - -**If you're using an external reference voltage (applied to the AREF pin), you must set the analog reference to EXTERNAL before calling analogRead().** -Otherwise, you will short together the active reference voltage -(internally generated) and the AREF pin, possibly damaging the -microcontroller on your Arduino board. - - - -Alternatively, you can connect the external reference voltage to -the AREF pin through a 5K resistor, allowing you to switch between -external and internal reference voltages. Note that the resistor -will alter the voltage that gets used as the reference because -there is an internal 32K resistor on the AREF pin. The two act as a -voltage divider, so, for example, 2.5V applied through the resistor -will yield 2.5 \* 32 / (32 + 5) = ~2.2V at the AREF pin. - - - -See also --------- - - -- `Description of the analog input pins `_ -- `analogRead `_\ () - - -- cgit v1.2.3