speed.cpp

00001 /*
00002  * PROGRAM RESPONSIBLE FOR open/close door.
00003  * ^^^^^^^ ^^^^^^^^^^^ ^^^ ^^^^^^^^^^ ^^^^
00004  *
00005  * FILE NAME: speed.cpp
00006  * USAGE: program that control the speed of servo motor.
00007  */
00008 
00009 
00010 /*
00011 * including the wanted library files.
00012 */
00013 #include "mbed.h"
00014 #include "speed.h"
00015 #include "Servo.h"
00016 
00017 /*--------------------------*\
00018  *  defineding the variables*
00019 \*--------------------------*/
00020 float varying_speed;
00021 float speed_now;
00022 int  delta_time;
00023 
00024 Ticker motor_timer;/* using ticker class which repeatedly call a function*/
00025 Servo motor_speed(p26); //     Servo PinName (pin)
00026 
00027 void motor (float speed, int time) { // void FunctionName (speed between 0-1, time in mS)
00028 // function responsible of increasing or decreasing the speed of the elevator softly
00029     if (time) {
00030         varying_speed= (speed - speed_now)/float (time);
00031         delta_time=time;
00032         /*---- Print message: shows motor speed at this point ------------------------------------*/
00033         printf("Motor going to speed %f over %f seconds\n",speed,float(time)/1000);
00034     } else {
00035         motor_speed = speed;
00036         /*---- Print message: shows motor speed at this point ------------------------------------*/
00037         printf("Motor at speed %f now\n",speed);
00038         speed_now=speed;
00039     }
00040 }
00041 
00042 void motor_update (void) { // function responsible of checking the speed is within servo rang (0-1)
00043     if (delta_time) {
00044 
00045         speed_now = speed_now + varying_speed; // event at reverst direction, this formela is removing the minus (all the result is positive)
00046         /* putting the speed in rang between 0 to 1 */
00047         if (speed_now>1.0) {
00048             speed_now =1;
00049         }
00050         if (speed_now<0.0) {
00051             speed_now=0;
00052         }
00053         motor_speed=speed_now;
00054         delta_time--; // decrease the time by 1
00055     }
00056 }
00057 
00058 void motor_start (void) {// a ticker function for the LED doors.
00059     speed_now = 0.5;
00060     motor_speed=speed_now; // stop the motor
00061     delta_time=0;          // at 0S time
00062     motor_timer.attach(&motor_update,0.001);// repeatedly call "motor_update" function.
00063 }