PING_rangefinder.h

00001 #pragma once
00002 #ifndef PING_RANGEFINDER_H
00003 #define PING_RANGEFINDER_H
00004 
00005 #include <processes.h>
00006 #include <Mutexes.h>
00007 #include <channels.h>
00008 #define PINGPIN p22
00009 
00010 
00011 //DigitalOut led3(LED3); //these LEDs are used to indicate when an interrupt occurs.
00012 //DigitalOut led4(LED4);
00013 //byte count = 0;
00014 
00015 class rangefinder {
00016 public:
00017     rangefinder()
00018             :Pinterrupt(PINGPIN), PingPin(PINGPIN)
00019      {
00020             //led3 = ~(led4 = 0);
00021             
00022             time = 0;
00023             enable_flag = false;
00024             set_interrupts();
00025             PingPin.mode(PullDown);
00026             //Pinterrupt.mode(PullDown);
00027     //        Pinterrupt.mode(PullUp);       
00028             PingPin.output(); //set pingpin as output
00029             PingPin = 0;
00030     }
00031 
00032     void ping() {
00033         T.reset(); //reset the timer to 0
00034         set_interrupts();
00035         enable_flag = false;
00036         PingPin.output(); //set as output
00037         PingPin = 0; //output initiation sequence of 0 1 0 to the rangefinder
00038         wait_us(2);
00039         PingPin = 1;
00040         wait_us(5);
00041         PingPin = 0;
00042         wait_us(1);
00043         //printf("now waiting for input.\n");
00044         PingPin.input(); //set as input
00045         wait_us(10);
00046         //set_interrupts();
00047         enable_flag = true;
00048         wait_ms(25); //more than required for maximum distance measurement
00049         
00050         
00051         
00052         //T.start(); //begin timing the length of time for an interrupt to occur
00053     }
00054     void set_interrupts()
00055     {
00056          Pinterrupt.fall(this, &rangefinder::set_time);
00057          Pinterrupt.rise(this, &rangefinder::start_timing);
00058     }
00059     void disable_interrupts()
00060     {
00061          Pinterrupt.fall(NULL);
00062          Pinterrupt.rise(NULL);
00063     
00064     } 
00065     void start_timing() {  OS::TISRW ISRW;
00066        if(enable_flag == true)
00067        {
00068            T.start();
00069            //led3 = !led3;
00070            //count++;       
00071        }
00072         
00073         //printf("start_timing called.\n");
00074     }
00075 
00076     void set_time() { OS::TISRW ISRW;
00077         if(enable_flag == true)
00078         {
00079             T.stop();
00080             //led4 = !led4;
00081             //disable_interrupts();
00082             //enable_flag = false;
00083             //printf("set_time being called...\n");
00084             time = T.read_us();
00085             //count++;
00086         }
00087                 //printf("value stored in time %f: \n", time);
00088         
00089         //PingPin.output();
00090         //PingPin = 0;
00091         //printf("PING:%f\n",get_time());
00092 
00093     }
00094    
00095 
00096 
00097     float get_time() {
00098        //disable_interrupts();
00099         return time/2.0;
00100         
00101     }
00102 
00103    
00104 private:
00105     Timer T;
00106     float time; //time in us
00107     InterruptIn Pinterrupt;
00108     DigitalInOut PingPin;
00109     bool enable_flag;
00110     //Ticker TICKER;// send_ticker;
00111     
00112 
00113 };
00114 
00115 
00116 
00117 
00118 
00119 
00120 
00121 
00122 
00123 
00124 extern BusOut leds;
00125 
00126 template<> OS_PROCESS void PING_PROC::Exec() //Output stream handling process
00127 {
00128     byte M = 0;
00129     rangefinder PING;
00130  
00131 
00132 char PIN_Return_chars[100]; //defined in accelerometer.h
00133      
00134      for(;;)
00135      {
00136        if(PING_MESSAGE.wait(80)) //length of time to wait also determines how rapidly to ticker ping
00137        {    leds = 0x2;
00138             M = PING_MESSAGE; //read the message that was destined for this process
00139             PING_MESSAGE.reset();
00140        
00141            if(M == 0) //then ping! command was sent
00142            {
00143                 {
00144                     //OS::TISRW ISRW; //this is a critical section as timing is involved
00145                     //this will not work though as it disables interrupts. 
00146                     PING.ping();
00147                 }
00148                 
00149                 {   
00150                     //TCritSect cs;
00151                     sprintf(PIN_Return_chars, "PING:%f\n", PING.get_time()); //
00152                  }
00153                  //Ser_out_Mutex.Lock();
00154                 //if(TX_Channel.get_free_size() > strlen(Return_chars)+1)
00155                     TX_channel.write(PIN_Return_chars, strlen(PIN_Return_chars)+1); //output the ping result
00156                 //Ser_out_Mutex.Unlock();
00157                 
00158                 
00159            }
00160        }
00161        if(M == 1) //ticker ping
00162        {
00163             {
00164                 //OS::TISRW ISRW; //this is a critical section as timing is involved
00165                 PING.ping();
00166             }
00167             //Sleep(2);
00168              {
00169                 //TCritSect cs;
00170                 sprintf(PIN_Return_chars, "PING:%f\n", PING.get_time()); //"PING:%f\n"
00171               }
00172               //Ser_out_Mutex.Lock();
00173               //if(TX_Channel.get_free_size() > strlen(Return_chars)+1)
00174                TX_channel.write(PIN_Return_chars, strlen(PIN_Return_chars)+1); //output the result
00175               //Ser_out_Mutex.Unlock();
00176              //TX_flag.Signal();
00177             
00178        }
00179        
00180               //PING_MESSAGE.reset();
00181             
00182         leds = 0x2;
00183        
00184      }
00185 }
00186 
00187  
00188  #endif
00189 
00190   //void enable_ticker() {
00191     //    TICKER.attach_us(this, &rangefinder::ping, TX_RATE); //call ping() every 40 ms
00192         //send_ticker.attach_us(this, &rangefinder::send_data, TX_RATE); //send the data out every 40 ms
00193     //}
00194     //void disable_ticker() {
00195         //printf("ticker should now be detached.\n");
00196     //    TICKER.detach();
00197         //send_ticker.detach();
00198     //}
00199  
00200 
00201 
00202 
00203