diff options
author | Perry Hung <iperry@gmail.com> | 2011-01-24 23:23:29 -0500 |
---|---|---|
committer | Perry Hung <iperry@gmail.com> | 2011-01-24 23:23:29 -0500 |
commit | c48689d34809943a5907884bd287cea9ae275352 (patch) | |
tree | d49ff06b0d4b81f6ab0eac8060d178ce7542476c /docs/source/arduino/static.rst | |
parent | 64431fd4b59cb8656365f1fad5f679cd4d756239 (diff) | |
parent | a9b2d70bc7799ca96c1673b18fe3012b1a4dd329 (diff) | |
download | librambutan-c48689d34809943a5907884bd287cea9ae275352.tar.gz librambutan-c48689d34809943a5907884bd287cea9ae275352.zip |
Merge remote branch 'leaf/master'
Diffstat (limited to 'docs/source/arduino/static.rst')
-rw-r--r-- | docs/source/arduino/static.rst | 71 |
1 files changed, 0 insertions, 71 deletions
diff --git a/docs/source/arduino/static.rst b/docs/source/arduino/static.rst deleted file mode 100644 index 1c0340e..0000000 --- a/docs/source/arduino/static.rst +++ /dev/null @@ -1,71 +0,0 @@ -.. _arduino-static: - -Static -====== - -The static keyword is used to create variables that are visible to -only one function. However unlike local variables that get created -and destroyed every time a function is called, static variables -persist beyond the function call, preserving their data between -function calls. - - - -Variables declared as static will only be created and initialized -the first time a function is called. - - - -Example -------- - -:: - - - - /* RandomWalk - * Paul Badger 2007 - * RandomWalk wanders up and down randomly between two - * endpoints. The maximum move in one loop is governed by - * the parameter "stepsize". - * A static variable is moved up and down a random amount. - * This technique is also known as "pink noise" and "drunken walk". - */ - - #define randomWalkLowRange -20 - #define randomWalkHighRange 20 - int stepsize; - - int thisTime; - int total; - - void setup() - { - Serial.begin(9600); - } - - void loop() - { // tetst randomWalk function - stepsize = 5; - thisTime = randomWalk(stepsize); - Serial.println(thisTime); - delay(10); - } - - int randomWalk(int moveSize){ - static int place; // variable to store value in random walk - declared static so that it stores - // values in between function calls, but no other functions can change its value - - place = place + (random(-moveSize, moveSize + 1)); - - if (place < randomWalkLowRange){ // check lower and upper limits - place = place + (randomWalkLowRange - place); // reflect number back in positive direction - } - else if(place > randomWalkHighRange){ - place = place - (place - randomWalkHighRange); // reflect number back in negative direction - } - - return place; - } - - |