Revision 3:01bc89d7ae8e, committed 2014-03-13

Comitter:

Markatron

Date:

Thu Mar 13 07:31:10 2014 +0000

Parent:

2:287a808baad7

Child:

4:aac581bec332

Commit message:

Finished adding functionality for the use of an encoder.

Changed in this revision

--- a/Car.cpp	Mon Mar 10 11:53:45 2014 +0000
+++ b/Car.cpp	Thu Mar 13 07:31:10 2014 +0000
@@ -34,12 +34,23 @@
 Car::Car(PinName servoPin, PinName motorPin) 
  : m_servo(servoPin), m_motor(motorPin) {
     m_speed = 15000;
+    m_countsPerRevolution = 0;
+    m_wheelCircumference = 0;
 }
 
-Car::Car(PinName servoPin, PinName motorPin, int countsPerRevolution, float wheelCircumference)
- : m_servo(servoPin), m_motor(motorPin) {
+Car::Car(PinName servoPin, PinName motorPin, int countsPerRevolution, float wheelCircumference, PinName sensorPin)
+ : m_servo(servoPin), m_motor(motorPin), m_sensor(sensorPin) {
     configureEncoder(countsPerRevolution, wheelCircumference);
+    
     m_speed = 15000;
+    setDirection(0);
+    
+    m_encoderCount = 0;
+    m_sensor.setSampleFrequency(1000);
+    m_sensor.setSamplesTillHeld(5);
+
+    Car* basePointer = dynamic_cast<Car*>(this);    
+    m_sensor.attach_deasserted_held(basePointer, &Car::updateEncoderCount);
 }
 
 Car::~Car() {
@@ -49,19 +60,29 @@
     m_speed = speed_us;
 }
 
+void Car::updateEncoderCount() {
+    m_encoderCount++;
+}
+
 void Car::forwards(float distance) {  
     
     int countsForward = (int)(distance * (m_countsPerRevolution / m_wheelCircumference));
     
-    // Tell encoder to keep reading, and have motor keep going forward
-    // until the specified number of counts (countsForward) has been read
-    // (e.g. countsForward = 10
-    //       while(encoderValue <= 10)
-    //       {
-    //           m_motor.pulsewidth(m_speed);
-    //       }
-    //       stop();
+    m_encoderCount = 0;
+    bool isMoving = true;
+    m_motor.pulsewidth_us(m_speed);
     
+    while(isMoving) {
+        wait(0.2); // <<-- for some unknown reason, this requires a delay to work :-S
+        if(countsForward < m_encoderCount)
+        {
+            isMoving = false;
+        }
+    }
+    // When it's finished, stop the buggy.
+    stop();
+    
+    return;
 }   
 
 void Car::forwards() {
@@ -103,25 +124,7 @@
 
 void Car::configureEncoder(int countsPerRevolution, float wheelCircumference) {
     m_countsPerRevolution = countsPerRevolution;
-    m_wheelCircumference = wheelCircumference;
+    m_wheelCircumference = wheelCircumference; 
 }
 
-/*
-** Takes a distance specified by user, and calculates how far will 
-** be travelled in 1 second. It then calculates the time that will 
-** be required to travel the specified distance from this result.
-** @params distance: The distance that needs to be converted into 
-** a time value.
-*/
-/*
-float Car::distanceToTimeConverter(float distance) {
-    float singleMovement = sqrt(distance);  // sqaure root of distance.
-    float time = 1;                         
-    
-    time = time + (distance / singleMovement);
-    
-    return time; 
-}
-*/
-
 #endif // CAR_C
\ No newline at end of file

--- a/Car.h	Mon Mar 10 11:53:45 2014 +0000
+++ b/Car.h	Thu Mar 13 07:31:10 2014 +0000
@@ -29,6 +29,7 @@
 #define CAR_H
 
 #include "mbed.h"
+#include "PinDetect.h"
 
 /**
 * RenBuggyServo Example:
@@ -60,7 +61,7 @@
     myCar.setSpeed(20000);
     myCar.setDirection(0);
     
-    myCar.forwards();
+    myCar.forwards();   
     wait(1);
     myCar.setDirection(45);
     wait(1);
@@ -87,17 +88,19 @@
     
     int m_speed;
     
+    int m_encoderCount;
+    
     int m_servoRange;       // Pulsewidth range to full left/right from centre (1.5ms)
     float m_servoDegrees;   // Angle to full right/left turn from centre (0).
     
     float m_wheelCircumference; // The circumference of the wheel with stripes.
     int m_countsPerRevolution;  // The number of stripes on the wheel.
-    //InterruptIn m_stripeInterrupt;
+    
+    PinDetect m_sensor; // For debouncing.
     
-    //float distanceToTimeConverter(float distance);
+    void updateEncoderCount();
     
-    public:
-    
+    public:    
     /** Constructs the car with PwmOut objects for servo and motor.
     * 
     * @param servoPin is the pin used for pwm output for driving the servo.
@@ -112,10 +115,11 @@
     * @param motorPin is the pin used for pwm output for driving the motor.
     * @param countsPerRevolution is the number of counts the encoder
     * makes in one full cycle of the wheel.
-    * @param wheelCircumference: The circumference of the wheel being
+    * @param wheelCircumference is the circumference of the wheel being
     * read by the encoder.
+    * @param sensorPin is the pin required for the encoder for debouncing.
     */
-    Car(PinName servoPin, PinName motorPin, int countsPerRevolution, float wheelCircumference);
+    Car(PinName servoPin, PinName motorPin, int countsPerRevolution, float wheelCircumference, PinName sensorPin);
     
     /**
     * Deconstructs the car.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PinDetect.lib	Thu Mar 13 07:31:10 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/AjK/code/PinDetect/#cb3afc45028b