GoalCounter.h

00001 #ifndef GOALCOUNTER_H
00002 #define GOALCOUNTER_H
00003 
00004 #include "mbed.h"
00005 
00006 /** GoalCounter class.
00007  *  Simple implementation of goal counter for table football using laser diode
00008  *  and phototransistor. Output of the phototransistor is connected to the digital
00009  *  input pin of MCU. When the laser beam is interrupted by ball passing the the cage
00010  *  Timer starts counting and measuring width of the pulse and if the duration of pulse
00011  *  is not longer than two seconds, goal is detected and _score variable is incremented.
00012  *   
00013  *  Pulse duration is also used for the calculation of ball passing speed. However,
00014  *  measurement is not precise.
00015  *
00016  * Example:
00017  * @code
00018  * #include "mbed.h"
00019  * #include "GoalCounter.h"
00020  * 
00021  * Timer t;
00022  * GoalCounter gc(D2, &t);
00023  * 
00024  * int main() {
00025  *  while(1) {
00026  *       if (gc.is_goal)
00027  *           goal(); // call some function
00028  *       }
00029  *   
00030  *   }
00031  * 
00032  * @endcode
00033  * 
00034  **/
00035  
00036 class GoalCounter {
00037 public:
00038     /**
00039     *   Constructor
00040     *
00041     *   @param pin Input pin where is the outpout of phototransistor connected
00042     *   @param timer reference to the Timer instance
00043     *
00044     */
00045     GoalCounter(PinName pin, Timer * t);
00046     /**
00047     *   Destructor
00048     *
00049     *   Destroys instance
00050     */
00051     ~GoalCounter();   
00052     /**
00053     *   Reads value of the timer, 
00054     *   this function is called from the interrupt pin fall edge callback
00055     */
00056     void tstart();
00057     /**
00058     *   Reads value from the timer and measures interval between end and beginning
00059     *   Called from the interrupt pin rise edge callback
00060     */
00061     void tstop();
00062     /**
00063     *   Returns score
00064     *   @return score score of the game
00065     */
00066     uint8_t get_score();
00067     /**
00068     *   Returns time of a ball pass for a given score
00069     *    @param score of the game
00070     *    @return time of a ball pass in seconds
00071     */
00072     float get_balltime(uint8_t score);
00073     /**
00074     *   Returns time of a ball pass for the current score
00075     *    @return time of a ball pass in seconds
00076     */
00077     float get_balltime();
00078     /**
00079     *   Returns speed of a ball pass for a given score
00080     *    @param score of the game
00081     *    @return speed of a ball pass in kph
00082     */
00083     float get_ballspeed(uint8_t score);
00084     /**
00085     *   Returns speed of a ball pass for the current score
00086     *    @return speed of a ball pass in kph
00087     */
00088     float get_ballspeed();
00089     /**
00090     *  Variable is 1 (true) when the goal is detected
00091     */
00092     volatile uint8_t is_goal;
00093 
00094 private:
00095     InterruptIn * _interrupt;
00096     volatile uint8_t _score;
00097     Timer * _t;
00098     float _balltimes[11]; // sorry for the FP arithmetics, i was too lazy to rewrite it
00099     float _time;
00100     float _begin;
00101     float _end;
00102     float _last_end;
00103     float _time_between;      
00104 };
00105 
00106 #endif