Diff: main.cpp

Revision:

0:a047182efa15

diff -r 000000000000 -r a047182efa15 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Nov 07 01:52:08 2016 +0000
@@ -0,0 +1,98 @@
+/*************************************************************************************
+Program Name: ES305 Laboratory Experiment 2, Part 1 - mbed serial setup and streaming
+Description: A basic code to read an analog channel and print the data to the serial port
+
+Date: 8/9/2016
+**************************************************************************************/
+
+// Include necessary libraries
+#include "mbed.h"
+#include "mbedWSEsbc.h"
+#define PI (3.14159)
+
+
+// Declare necessary objects
+DigitalOut myled(LED1); 
+
+
+// variables for data handling and storage
+float Ts; // Sampling period 1/Ts Hz
+float TotalTime; // Total run time
+float ang,angp,speed; // variables for approximating speed from encoder measurements
+float dc; // duty cycle applied to motor
+long enc1; // encoder variable
+float Time; // elapsed time
+float dt; // desired loop duration
+float DC; // duty cycle specified by user
+
+
+
+int main ()
+{
+    // Initializes mbed to access functionality of encoder, A/D, driver, etc. chipsets
+    // Input is baud rate for PC communication
+    mbedWSEsbcInit(115200); // also initializes timer object t
+    mot_en1.period(0.020); // sets PWM period to 0.02 seconds
+
+    while(1) {
+        
+        // Wait for user input to begin loop
+        pc.scanf("%f,%f,%f",&TotalTime,&Ts,&DC);
+        
+        Time = 0.0; // reset time variable
+        t.reset(); // reset timer object
+
+        
+        
+        angp = 0; // initialize previous angle variable to zero
+
+        myled = 1; // turn on light to indicate it's sampling
+        
+        while(Time <= TotalTime) {
+            t.start(); // start measuring comp time
+
+            // Read encoder
+            enc1 = LS7366_read_counter(1); // input is the encoder channel
+            pc.printf("counts = %f\n\r",enc1);
+
+            // Convert from counts to radians
+            ang = 2*PI*enc1/6500.0;
+
+            // Estimate speed
+            speed = (ang-angp)/Ts;
+
+            // Age variables
+            angp = ang;
+
+            // compute duty cycle for motor using proportional control scheme
+            if(Time<0.1) {
+                dc = 0.0;
+            } else {
+                dc = DC;
+            }
+
+            // motor control
+            mot_control(1,dc); // first input is the motor channel, second is duty cycle 
+
+
+            pc.printf("%f,%f,%f\n\r",Time,speed,dc);
+
+
+            Time = Time + Ts;  // update time
+
+            // wait to achieve sampling rate
+            dt = Ts - t.read();
+            if(dt<0.0) {
+                dt = 0.0;
+            }
+            wait(dt);
+
+            t.reset();
+        
+              
+        } // end while(Time<=Ttime)
+        mot_control(1,0.0); // turn motor off at end of test
+        myled = 0; // turn off light to indicate it has finished
+        
+    }// end while(repeat==1)
+}// end main
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