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authorMarti Bolivar <mbolivar@mit.edu>2010-10-20 06:46:52 -0400
committerMarti Bolivar <mbolivar@mit.edu>2010-10-20 06:46:52 -0400
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+.. _arduino-randomseed:
+
+randomSeed(seed)
+================
+
+Description
+-----------
+
+randomSeed() initializes the pseudo-random number generator,
+causing it to start at an arbitrary point in its random sequence.
+This sequence, while very long, and random, is always the same.
+
+
+
+If it is important for a sequence of values generated by random()
+to differ, on subsequent executions of a sketch, use randomSeed()
+to initialize the random number generator with a fairly random
+input, such as analogRead() on an unconnected pin.
+
+
+
+Conversely, it can occasionally be useful to use pseudo-random
+sequences that repeat exactly. This can be accomplished by calling
+randomSeed() with a fixed number, before starting the random
+sequence.
+
+
+
+Parameters
+----------
+
+long, int - pass a number to generate the seed.
+
+
+
+Returns
+-------
+
+no returns
+
+
+
+Example
+-------
+
+::
+
+ long randNumber;
+
+ void setup(){
+ Serial.begin(9600);
+ randomSeed(analogRead(0));
+ }
+
+ void loop(){
+ randNumber = random(300);
+ Serial.println(randNumber);
+
+ delay(50);
+ }
+
+
+
+See also
+--------
+
+
+- `random <http://arduino.cc/en/Reference/Random>`_
+
+