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author | Marti Bolivar <mbolivar@mit.edu> | 2010-11-28 11:23:33 -0500 |
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committer | Marti Bolivar <mbolivar@mit.edu> | 2010-11-28 11:23:33 -0500 |
commit | d9cbd78e29d42e70bb46641dd43ee0772c8c975f (patch) | |
tree | 80a67cba4468dbcd89b3cd23ad56695b1f146c66 /source/lang/pulsein.rst | |
parent | 546b34076d230b617ba86defb6b90cd934b01878 (diff) | |
download | librambutan-d9cbd78e29d42e70bb46641dd43ee0772c8c975f.tar.gz librambutan-d9cbd78e29d42e70bb46641dd43ee0772c8c975f.zip |
reorganized all the arduino/ docs into a lang/ subdirectory since
they're properly CC attributed now.
Diffstat (limited to 'source/lang/pulsein.rst')
-rw-r--r-- | source/lang/pulsein.rst | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/source/lang/pulsein.rst b/source/lang/pulsein.rst new file mode 100644 index 0000000..7bbe84c --- /dev/null +++ b/source/lang/pulsein.rst @@ -0,0 +1,82 @@ +.. _lang-pulsein: + +pulseIn() +========= + +Description +----------- + +Reads a pulse (either HIGH or LOW) on a pin. For example, if +**value** is **HIGH**, **pulseIn()** waits for the pin to go +**HIGH**, starts timing, then waits for the pin to go **LOW** and +stops timing. Returns the length of the pulse in microseconds. +Gives up and returns 0 if no pulse starts within a specified time +out. + + + +The timing of this function has been determined empirically and +will probably show errors in longer pulses. Works on pulses from 10 +microseconds to 3 minutes in length. + + + +Syntax +------ + +pulseIn(pin, value) +pulseIn(pin, value, timeout) + + + +Parameters +---------- + +pin: the number of the pin on which you want to read the pulse. +(*int*) + + + +value: type of pulse to read: either +`HIGH <http://arduino.cc/en/Reference/Constants>`_ or +`LOW <http://arduino.cc/en/Reference/Constants>`_. (*int*) + + + +timeout (optional): the number of microseconds to wait for the +pulse to start; default is one second (*unsigned long*) + + + +Returns +------- + +the length of the pulse (in microseconds) or 0 if no pulse started +before the timeout (*unsigned long*) + + + +Example +------- + +:: + + + + int pin = 7; + unsigned long duration; + + void setup() + { + pinMode(pin, INPUT); + } + + void loop() + { + duration = pulseIn(pin, HIGH); + } + + + + +.. include:: cc-attribution.txt |