Eric Boynton / Mbed 2 deprecated ES305_Lab6_copy

Lab 6 code to read DC motor and ouput time, speed, and duty cycle

Dependencies:   mbed mbedWSEsbc

main.cpp@0:a047182efa15, 2016-11-07 (annotated)

Committer:
m170594
Date:
Mon Nov 07 01:52:08 2016 +0000
Revision:
0:a047182efa15
ES305 Lab 6

Who changed what in which revision?

UserRevisionLine numberNew contents of line
m170594 0:a047182efa15 1 /*************************************************************************************
m170594 0:a047182efa15 2 Program Name: ES305 Laboratory Experiment 2, Part 1 - mbed serial setup and streaming
m170594 0:a047182efa15 3 Description: A basic code to read an analog channel and print the data to the serial port
m170594 0:a047182efa15 4
m170594 0:a047182efa15 5 Date: 8/9/2016
m170594 0:a047182efa15 6 **************************************************************************************/
m170594 0:a047182efa15 7
m170594 0:a047182efa15 8 // Include necessary libraries
m170594 0:a047182efa15 9 #include "mbed.h"
m170594 0:a047182efa15 10 #include "mbedWSEsbc.h"
m170594 0:a047182efa15 11 #define PI (3.14159)
m170594 0:a047182efa15 12
m170594 0:a047182efa15 13
m170594 0:a047182efa15 14 // Declare necessary objects
m170594 0:a047182efa15 15 DigitalOut myled(LED1);
m170594 0:a047182efa15 16
m170594 0:a047182efa15 17
m170594 0:a047182efa15 18 // variables for data handling and storage
m170594 0:a047182efa15 19 float Ts; // Sampling period 1/Ts Hz
m170594 0:a047182efa15 20 float TotalTime; // Total run time
m170594 0:a047182efa15 21 float ang,angp,speed; // variables for approximating speed from encoder measurements
m170594 0:a047182efa15 22 float dc; // duty cycle applied to motor
m170594 0:a047182efa15 23 long enc1; // encoder variable
m170594 0:a047182efa15 24 float Time; // elapsed time
m170594 0:a047182efa15 25 float dt; // desired loop duration
m170594 0:a047182efa15 26 float DC; // duty cycle specified by user
m170594 0:a047182efa15 27
m170594 0:a047182efa15 28
m170594 0:a047182efa15 29
m170594 0:a047182efa15 30 int main ()
m170594 0:a047182efa15 31 {
m170594 0:a047182efa15 32 // Initializes mbed to access functionality of encoder, A/D, driver, etc. chipsets
m170594 0:a047182efa15 33 // Input is baud rate for PC communication
m170594 0:a047182efa15 34 mbedWSEsbcInit(115200); // also initializes timer object t
m170594 0:a047182efa15 35 mot_en1.period(0.020); // sets PWM period to 0.02 seconds
m170594 0:a047182efa15 36
m170594 0:a047182efa15 37 while(1) {
m170594 0:a047182efa15 38
m170594 0:a047182efa15 39 // Wait for user input to begin loop
m170594 0:a047182efa15 40 pc.scanf("%f,%f,%f",&TotalTime,&Ts,&DC);
m170594 0:a047182efa15 41
m170594 0:a047182efa15 42 Time = 0.0; // reset time variable
m170594 0:a047182efa15 43 t.reset(); // reset timer object
m170594 0:a047182efa15 44
m170594 0:a047182efa15 45
m170594 0:a047182efa15 46
m170594 0:a047182efa15 47 angp = 0; // initialize previous angle variable to zero
m170594 0:a047182efa15 48
m170594 0:a047182efa15 49 myled = 1; // turn on light to indicate it's sampling
m170594 0:a047182efa15 50
m170594 0:a047182efa15 51 while(Time <= TotalTime) {
m170594 0:a047182efa15 52 t.start(); // start measuring comp time
m170594 0:a047182efa15 53
m170594 0:a047182efa15 54 // Read encoder
m170594 0:a047182efa15 55 enc1 = LS7366_read_counter(1); // input is the encoder channel
m170594 0:a047182efa15 56 pc.printf("counts = %f\n\r",enc1);
m170594 0:a047182efa15 57
m170594 0:a047182efa15 58 // Convert from counts to radians
m170594 0:a047182efa15 59 ang = 2*PI*enc1/6500.0;
m170594 0:a047182efa15 60
m170594 0:a047182efa15 61 // Estimate speed
m170594 0:a047182efa15 62 speed = (ang-angp)/Ts;
m170594 0:a047182efa15 63
m170594 0:a047182efa15 64 // Age variables
m170594 0:a047182efa15 65 angp = ang;
m170594 0:a047182efa15 66
m170594 0:a047182efa15 67 // compute duty cycle for motor using proportional control scheme
m170594 0:a047182efa15 68 if(Time<0.1) {
m170594 0:a047182efa15 69 dc = 0.0;
m170594 0:a047182efa15 70 } else {
m170594 0:a047182efa15 71 dc = DC;
m170594 0:a047182efa15 72 }
m170594 0:a047182efa15 73
m170594 0:a047182efa15 74 // motor control
m170594 0:a047182efa15 75 mot_control(1,dc); // first input is the motor channel, second is duty cycle
m170594 0:a047182efa15 76
m170594 0:a047182efa15 77
m170594 0:a047182efa15 78 pc.printf("%f,%f,%f\n\r",Time,speed,dc);
m170594 0:a047182efa15 79
m170594 0:a047182efa15 80
m170594 0:a047182efa15 81 Time = Time + Ts; // update time
m170594 0:a047182efa15 82
m170594 0:a047182efa15 83 // wait to achieve sampling rate
m170594 0:a047182efa15 84 dt = Ts - t.read();
m170594 0:a047182efa15 85 if(dt<0.0) {
m170594 0:a047182efa15 86 dt = 0.0;
m170594 0:a047182efa15 87 }
m170594 0:a047182efa15 88 wait(dt);
m170594 0:a047182efa15 89
m170594 0:a047182efa15 90 t.reset();
m170594 0:a047182efa15 91
m170594 0:a047182efa15 92
m170594 0:a047182efa15 93 } // end while(Time<=Ttime)
m170594 0:a047182efa15 94 mot_control(1,0.0); // turn motor off at end of test
m170594 0:a047182efa15 95 myled = 0; // turn off light to indicate it has finished
m170594 0:a047182efa15 96
m170594 0:a047182efa15 97 }// end while(repeat==1)
m170594 0:a047182efa15 98 }// end main