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author | Marti Bolivar <mbolivar@mit.edu> | 2010-10-20 06:46:52 -0400 |
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committer | Marti Bolivar <mbolivar@mit.edu> | 2010-10-20 06:46:52 -0400 |
commit | 85c1c72db022bba891868afd3375e39dbe245701 (patch) | |
tree | 9d86a3db825667362a8c89a98a205586015aec94 /source/arduino/randomseed.rst | |
parent | abcfcc62cc62dfc088d30d5a6b6c36d6c89f7b07 (diff) | |
download | librambutan-85c1c72db022bba891868afd3375e39dbe245701.tar.gz librambutan-85c1c72db022bba891868afd3375e39dbe245701.zip |
initial check-in of arduino docs in RST format (converted using wget+pandoc)
Diffstat (limited to 'source/arduino/randomseed.rst')
-rw-r--r-- | source/arduino/randomseed.rst | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/source/arduino/randomseed.rst b/source/arduino/randomseed.rst new file mode 100644 index 0000000..b0b5d71 --- /dev/null +++ b/source/arduino/randomseed.rst @@ -0,0 +1,70 @@ +.. _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>`_ + + |