Chris Styles / Mbed 2 deprecated m3pi_LineFollower_PID

An example PID line following program

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Revision 0:78f9794620a3, committed 2011-05-12

Comitter:
chris
Date:
Thu May 12 11:48:56 2011 +0000
Commit message:

Changed in this revision

m3pi.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m3pi.lib	Thu May 12 11:48:56 2011 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/chris/code/m3pi/#9b128cebb3c2

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu May 12 11:48:56 2011 +0000
@@ -0,0 +1,70 @@
+#include "mbed.h"
+#include "m3pi.h"
+
+m3pi m3pi;
+
+// Minimum and maximum motor speeds
+#define MAX 1.0
+#define MIN 0
+
+// PID terms
+#define P_TERM 1
+#define I_TERM 0
+#define D_TERM 20
+
+int main() {
+
+    m3pi.locate(0,1);
+    m3pi.printf("Line PID");
+
+    wait(2.0);
+
+    m3pi.sensor_auto_calibrate();
+
+    float right;
+    float left;
+    float current_pos_of_line = 0.0;
+    float previous_pos_of_line = 0.0;
+    float derivative,proportional,integral = 0;
+    float power;
+    float speed = MAX;
+    
+    while (1) {
+
+        // Get the position of the line.
+        current_pos_of_line = m3pi.line_position();        
+        proportional = current_pos_of_line;
+        
+        // Compute the derivative
+        derivative = current_pos_of_line - previous_pos_of_line;
+        
+        // Compute the integral
+        integral += proportional;
+        
+        // Remember the last position.
+        previous_pos_of_line = current_pos_of_line;
+        
+        // Compute the power
+        power = (proportional * (P_TERM) ) + (integral*(I_TERM)) + (derivative*(D_TERM)) ;
+        
+        // Compute new speeds   
+        right = speed+power;
+        left  = speed-power;
+        
+        // limit checks
+        if (right < MIN)
+            right = MIN;
+        else if (right > MAX)
+            right = MAX;
+            
+        if (left < MIN)
+            left = MIN;
+        else if (left > MAX)
+            left = MAX;
+            
+       // set speed 
+        m3pi.left_motor(left);
+        m3pi.right_motor(right);
+
+    }
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Thu May 12 11:48:56 2011 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/e2ac27c8e93e