main.cpp

00001 #include "mbed.h"
00002 #include "mbedWSEsbc.h"
00003 #define PI (3.14159)
00004 
00005 // Declare objects (if necessary)
00006 Ticker Controller; // declare Ticker object named "Controller"
00007 DigitalOut myled(LED1); // LED, flash lights for debugging
00008 
00009 
00010 // variables for data handling and storage
00011 float TotalTime;        // Total run time
00012 float Time;             // Current elapsed time
00013 float Ts = 0.0083;      // Control update period (seconds) (120 Hz equivalent)
00014 float Tstrm = 0.01;     // Data streaming period (seconds) (100 Hz equivalent)
00015 float ang,angp,speed;   // variables for approximating speed from encoder measurements
00016 float DCAmp;            // duty cycle applied to motor
00017 float dc;               // duty cycle
00018 long enc1;              // encoder variable
00019 float lowDC;
00020 
00021 
00022 // Function definition Prototypes (declarations)
00023 void twoStepCode(); // declare that a separate (other than main) function named "ctrCode" exists
00024 
00025 // Enter main function
00026 int main ()
00027 {
00028     // Initializes mbed to access functionality of encoder, A/D, driver, etc. chipsets
00029     // Input is baud rate for PC communication
00030     mbedWSEsbcInit(115200); // also initializes timer object t
00031     mot_en1.period(0.020); // sets PWM period to 0.02 seconds for best DC motor operation
00032 
00033     while(1) {
00034         // Scan serial port for user input to begin experiment
00035         pc.scanf("%f,%f",&TotalTime,&lowDC); //&DCAmp,&lowDC);
00036         // perform necessary functions to time the experiment
00037         Time = 0.0; // reset time variable
00038         t.reset(); // reset timer object
00039         // Attach the ctrCode function to ticker object specified with period Ts
00040         Controller.attach(&twoStepCode,Ts);
00041         t.start(); // start measuring elapsed time
00042         // perform operations while the elapsed time is less than the desired total time
00043         while(Time <= TotalTime) {
00044             // send data over serial port
00045             pc.printf("%f,%f,%f\n",Time,speed,dc);
00046             wait(Tstrm); // print data at approximately 50 Hz
00047         } // end while(Time<=Ttime)
00048         Controller.detach(); // detach ticker to turn off controller
00049         // Turn motor off at end of experiment
00050         mot_control(1,0.0);
00051     }// end while(1)
00052 }// end main
00053 // Additional function definitions
00054 void twoStepCode() // function to attach to ticker
00055 {
00056     myled = !myled; // toggle LED 2 to indicate control update
00057     // read current elapsed time
00058     Time = t.read();
00059     // Read encoder
00060     enc1 = LS7366_read_counter(1); // input is the encoder channel
00061     // Convert from counts to radians
00062     ang = 2.0*PI*enc1/6400.0;
00063     // Estimate speed
00064     speed = (ang-angp)/Ts;
00065     // Age variables
00066     angp = ang;
00067     // compute duty cycle for motor (will be changed later!)
00068     //dc = DCAmp*sin(2.0*PI/5.0*Time); // user-specified duty cycle
00069     // Lab3 DC
00070     if(Time<0.1) {
00071         dc = 0.0;
00072     } else if(Time<0.55) {
00073         dc = lowDC;
00074     } else {
00075         dc = 0.10;
00076     } 
00077     // motor control
00078     mot_control(1,dc); // first input is the motor channel, second is duty cycle
00079 } // end ctrCode()