PushDuration.h

00001 /** 
00002  * PushDuration Library by Jens Strümper. For questions or suggestions on how to improve the 
00003  * library please contact me via email: jens.struemper@gmail.com
00004 **/
00005 #ifndef __PUSHDURATION_H_INCLUDED__
00006 #define __PUSHDURATION_H_INCLUDED__
00007 
00008 namespace js{
00009 
00010 /**
00011  * PushDuration calls a function based on the duration of a button push
00012  *
00013  * The following code demonstrates the usage of the PushDuration library. 
00014  * The library is meant for cases where different callbank functions are triggered by 
00015  * different button push durations. E.g function "state1" is called when the button is
00016  * released after 1 second, "state4" is called when the button is released after 4 seconds
00017  * and so on. Please note that the implementation is far from being perfect. E.g. it 
00018  * will not work if you instantiate the class in ram. 
00019 
00020 * Paramters are:-
00021  *  <ul>
00022  *  <li> Key value table for function <-> duration assignment. </li>
00023  *  <li> PinName used for Button </li> 
00024  *  <li> Interval - typically "1" for full seconds </li>
00025  *  </ul>
00026  *
00027  *
00028  * Example:
00029  * @code
00030 
00031 
00032  * #include "mbed.h"
00033  * #include "PushDuration.h"
00034 
00035  * void state1() {
00036  *    //function called after 1 seconds
00037  *    printf("state1\n");
00038  * }
00039  * void state4() {
00040  *    //function called after 4 seconds
00041  *   printf("state4\n");
00042  * }
00043  * void state10() {
00044  *   //function called after 4 seconds
00045  *   printf("state8\n");
00046  * }
00047 
00048  * PinName pin(p17);
00049 
00050  * //Action Table specifiying push duration and callback function
00051  * const action action_table[] =
00052  * {
00053  *     { 1, state1 },
00054  *     { 4, state4 },
00055  *     { 10, state10 },
00056  * };
00057 
00058  * int main()
00059  * //creating the ButtonHandler Object by specifiying arraysize, action table, pin and interval in seconds 
00060  * {
00061  *     ButtonHandler green(
00062  *     sizeof(action_table)/sizeof(action_table[0]),
00063  *     action_table,
00064  *     pin,
00065  *     2
00066  *     );
00067 
00068  * //enabling Button Handler
00069  *     green.enable();
00070  *     while(1){
00071  *         printf("alive\n");
00072  *         wait(5);
00073  *      }
00074  * }
00075 **/
00076 
00077 /**
00078  * struct to define duration and 
00079  * callback function
00080 **/
00081 
00082 struct action
00083 {
00084     int counter_limit;
00085     void (*transition)(void);
00086 };
00087 
00088 /**
00089  * struct to hold table size and p
00090  * pointer to the first element of the table
00091 **/
00092 
00093 struct action_list
00094 {
00095     size_t size;
00096     const action *table;
00097 };
00098 
00099 
00100 class ButtonHandler {
00101 public:
00102     /**
00103      * ButtonHandler Constructor:
00104      *
00105      * @param table_size sitze_t
00106      * @param begin  const action*
00107      * @param pin PinName
00108      * @param seconds float
00109     **/
00110     ButtonHandler(std::size_t table_size, const action* begin, PinName pin, float seconds ): buttonPin(pin){
00111         mTable.size = table_size;
00112         mTable.table = begin;
00113         intervalInSeconds = seconds;
00114         printf("initialized\n");
00115     }
00116 
00117     /**
00118      * Enables Button Handler 
00119     **/
00120     void enable();
00121     
00122     /**
00123      * Disables Button Handler 
00124     **/
00125     
00126     void disable();
00127     
00128     /**
00129      * ButtonHandler Destructor 
00130     **/
00131     virtual ~ButtonHandler() {
00132         disable();
00133     }
00134 protected:
00135     void press();
00136     void secondsCount();
00137     void release();
00138     void react(int counter) const;
00139     
00140 private:
00141     volatile unsigned counter;
00142     InterruptIn buttonPin;
00143     float intervalInSeconds;
00144     action_list mTable;
00145     Ticker ticker;
00146     
00147 };
00148 }; //name space ends
00149 
00150 using namespace js; 
00151 
00152 #endif //__PUSHDURATION_H_INCLUDED__