Revision 0:871adb9cf798, committed 2015-12-08

Comitter:

electromotivated

Date:

Tue Dec 08 00:11:04 2015 +0000

Commit message:

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Changed in this revision

diff -r 000000000000 -r 871adb9cf798 MotorDriver.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MotorDriver.cpp	Tue Dec 08 00:11:04 2015 +0000
@@ -0,0 +1,96 @@
+#include "MotorDriver.h"
+#include "mbed.h"
+#include <cmath>
+
+// See .h file for function descriptions and details
+
+MotorDriver::MotorDriver(DigitalOut in1, DigitalOut in2, PwmOut pwm, float pwmFreq, bool isBrakeable) 
+                        : _in1(in1), _in2(in2), _pwm(pwm) 
+{
+    // Initialize motor and variables
+    _in1 = 1; _in2 = 0; _pwm = 0.0; this->isBrakeable = isBrakeable;
+    _pwm.period(1.0/pwmFreq);
+    determineState();
+}
+
+void MotorDriver::determineState(){
+    if(_in1==1 && _in2==1){
+        motor_state.code  = BRAKING;
+        motor_state.value = _pwm;    
+    }
+    else if(_in1==1 && _in2==0){
+        motor_state.code  = DRIVING_CW;
+        motor_state.value = _pwm;
+    }
+    else if(_in1==0 && _in2==1){
+        motor_state.code  = DRIVING_CCW;
+        motor_state.value = _pwm;  
+    }
+    else if(_in1==0 && _in2==0){
+        motor_state.code = COASTING;
+        motor_state.value = _pwm;
+    }
+    else{
+        motor_state.code = ERROR;       // Undefined config found
+        motor_state.value = _pwm;
+    }    
+}
+
+State_t MotorDriver::setSpeed(float speed){
+    // Prevent instantaneous reversal; put into brake if requested to do so
+    bool isTryingToInstantReverse = 
+         (bool)((speed < 0.0) && (motor_state.code == DRIVING_CW) && (_pwm > 0.05)) || 
+         (bool)((speed > 0.0) && (motor_state.code == DRIVING_CCW)&& (_pwm > 0.05));
+    if(isTryingToInstantReverse){
+        // Set motor to brake, set state to error
+        coast();
+        motor_state.code = ERROR; motor_state.value = _pwm;
+        return motor_state;
+    }
+    else{
+        if(speed == 0.0)
+        {
+            // No effect to _in pins
+        }
+        else{
+            _in1 = (speed>0.0);
+            _in2 = (speed<0.0);
+        }
+        _pwm = std::abs(speed);
+        determineState();
+        return motor_state;
+    }
+}
+
+State_t MotorDriver::forceSetSpeed(float speed){
+    if(speed == 0.0)
+        {
+            // No effect to _in pins
+        }
+        else{
+            _in1 = (speed>0.0);
+            _in2 = (speed<0.0);
+        }
+        _pwm = std::abs(speed);
+        determineState();
+        return motor_state;
+}
+
+State_t MotorDriver::brake(float intensity){
+    if(!isBrakeable) coast();
+    else{
+        _in1=1; _in2=1; _pwm = _pwm * (1.0-intensity);  
+    }
+    determineState();
+    return motor_state;
+}
+
+State_t MotorDriver::coast(){
+    _in1=0; _in2=0; _pwm = 1.0;
+    determineState();
+    return motor_state;
+}
+
+State_t MotorDriver::getState(){
+    return motor_state;
+}
\ No newline at end of file

diff -r 000000000000 -r 871adb9cf798 MotorDriver.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MotorDriver.h	Tue Dec 08 00:11:04 2015 +0000
@@ -0,0 +1,103 @@
+/*
+Bryce Williams
+09/14/2014
+
+General/Basic Motor Driver Class providing Motor Control using a COTS Motor Driver
+
+    Class based off of Christopher Hasler's Motordriver library found at
+    https://developer.mbed.org/cookbook/Motor 
+    
+    
+* Permission is hereby granted, free of charge, to any person obtaining a copy
+* of this software and associated documentation files (the "Software"), to deal
+* in the Software without restriction, including without limitation the rights
+* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+* copies of the Software, and to permit persons to whom the Software is
+* furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+* THE SOFTWARE.
+*/
+
+#ifndef MOTORDRIVER_H
+#define MOTORDRIVER_H
+
+#include "mbed.h"
+
+typedef enum {ERROR=0, DRIVING_CW=1, DRIVING_CCW=2, BRAKING=3, COASTING=4}Code_t;
+typedef struct{
+    Code_t code;     
+    float  value;
+}State_t;
+
+class MotorDriver{
+    public:
+        /*
+            Constructor of MotorDriver Objects
+            @param in_1         Direction Input 1
+            @param in_2         Direction Input 2
+            @param pwm          PWM speed control input
+            @param pwmFreq      PWM frequency, some motors may whine at lower freqs
+            @param isBrakable   Boolean value indicating whether or not the 
+                                motor driver is brakeable(see your datasheet)
+        */
+        MotorDriver(DigitalOut in1, DigitalOut in2, PwmOut pwm, float pwmFreq, bool isBrakeable = false);
+        
+        /*
+            Sets speed of motor normalized between -1.0 to 1.0 
+            @param speed    Value -1.0 to 1.0 (>0 CW at speed as percentage)
+                                              (<0 CCW at speed as percentage)
+                                              (=0 speed is zero)
+            @return state of the motor
+            NOTE: This method will NOT allow user to instantaneously swithch 
+            from CW to CCW or vise versa. Doing so will cause the motor to 
+            be put in to a BRAKE condition, while the motor_state.code will 
+            be updated to ERROR. User should avoid trying to do this, call 
+            first setSpeed(0) or brake().  
+        */
+        State_t setSpeed(float speed);
+        
+        /*
+            Same as setSpeed(float speed), however does not impose the safety disallowing
+            instantaneous reversal of motor direction. It is up to the user to ensure they
+            do not blow up their motor. 
+        */
+        State_t forceSetSpeed(float speed);
+        
+        /*
+            Put motor into braked config
+            @param intensity How hard to brake (0.0 to 1.0)
+            @return state of the motors
+        */
+        State_t brake(float intensity);
+        
+        /*
+            Put motor into stop/coast config
+        */
+        State_t coast();
+        
+        
+        /*
+            Get state of the motor
+            @return state of the motor
+        */
+        State_t getState();
+        
+    protected:                        // Protected so objects that inherit can access
+        State_t    motor_state;
+        DigitalOut _in1;
+        DigitalOut _in2;
+        PwmOut     _pwm;
+        bool       isBrakeable;
+        void determineState();        // Determine motor state based on in1, in2, and pwm
+};
+
+#endif
\ No newline at end of file