Revision 0:83245b45ea70, committed 2011-02-23

Comitter:

osmeest

Date:

Wed Feb 23 23:12:44 2011 +0000

Commit message:

Slightly improvement over original: brakeable is a bool and state() should be const.

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/motordriver.cpp	Wed Feb 23 23:12:44 2011 +0000
@@ -0,0 +1,140 @@
+/*motor driver libary modified from the following libary,
+*
+* mbed simple H-bridge motor controller
+* Copyright (c) 2007-2010, sford
+*
+* by Christopher Hasler.
+*
+* from sford's libary,
+*
+* 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.
+*/
+
+#include "motordriver.h"
+
+#include "mbed.h"
+
+Motor::Motor(PinName pwm, PinName fwd, PinName rev, bool brakeable):
+        _pwm(pwm), _fwd(fwd), _rev(rev), _brakeable(brakeable), _sign(0) {
+
+    // Set initial condition of PWM
+    _pwm.period(0.001);
+    _pwm = 0;
+
+    // Initial condition of output enables
+    _fwd = 0;
+    _rev = 0;
+}
+
+float Motor::speed(float speed) {
+    float temp = 0;
+    if (_sign == 0) {
+        _fwd = (speed > 0.0);
+        _rev = (speed < 0.0);
+        temp = abs(speed);
+        _pwm = temp;
+    } else if (_sign == 1) {
+        if (speed < 0) {
+            _fwd = (speed > 0.0);
+            _rev = (speed < 0.0);
+            _pwm = 0;
+            temp = 0;
+       } else {
+            _fwd = (speed > 0.0);
+            _rev = (speed < 0.0);
+            temp = abs(speed);
+            _pwm = temp;
+        }
+    } else if (_sign == -1) {
+        if (speed > 0) {
+            _fwd = (speed > 0.0);
+            _rev = (speed < 0.0);
+            _pwm = 0;
+            temp = 0;
+        } else {
+            _fwd = (speed > 0.0);
+            _rev = (speed < 0.0);
+            temp = abs(speed);
+            _pwm = temp;
+        }
+    }
+    if (speed > 0)
+        _sign = 1;
+    else if (speed < 0) {
+        _sign = -1;
+    } else if (speed == 0) {
+        _sign = 0;
+    }
+    return temp;
+}
+//  (additions)
+void Motor::coast(void) {
+    _fwd = 0;
+    _rev = 0;
+    _pwm = 0;
+    _sign = 0;
+}
+
+float Motor::stop(float duty) {
+    if (_brakeable == 1) {
+        _fwd = 1;
+        _rev = 1;
+        _pwm = duty;
+        _sign = 0;
+        return duty;
+    } else
+        Motor::coast();
+        return -1; // error, can't brake
+}
+
+float Motor::state(void) const {
+    int fwd = _fwd.read();
+    int rev = _rev.read();
+    float pwm = _pwm.read();
+    
+    if ((fwd == rev) && (pwm > 0)) {
+        return -2;//braking
+    } else if (pwm == 0) {
+        return 2;//coasting
+    } else if ((fwd == 0) && (rev == 1)) {
+        return -pwm;//reversing
+    }  else if ((fwd == 1) && (rev == 0)) {
+        return pwm;//fowards
+    } else
+        return -3;//error
+}
+
+/*
+ test code, this demonstrates working motor drivers.
+
+Motor A(p22, p6, p5, 1); // pwm, fwd, rev, can break
+Motor B(p21, p7, p8, 1); // pwm, fwd, rev, can break
+int main() {
+    for (float s=-1.0; s < 1.0 ; s += 0.01) {
+       A.speed(s);
+       B.speed(s);
+       wait(0.02);
+    }
+    A.stop();
+    B.stop();
+    wait(1);
+    A.coast();
+    B.coast();
+}
+*/
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/motordriver.h	Wed Feb 23 23:12:44 2011 +0000
@@ -0,0 +1,91 @@
+/*motor driver libary modified from the following libary,
+*  
+* mbed simple H-bridge motor controller
+* Copyright (c) 2007-2010, sford
+* 
+* by Christopher Hasler.
+* 
+* from sford's libary,
+*
+* 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 MBED_MOTOR_H
+#define MBED_MOTOR_H
+ 
+#include "mbed.h"
+ 
+/** Interface to control a standard DC motor 
+* with an H-bridge using a PwmOut and 2 DigitalOuts
+*/
+class Motor {
+    public:
+ 
+/** Create a motor control interface    
+*
+* @param pwm A PwmOut pin, driving the H-bridge enable line to control the speed
+* @param fwd A DigitalOut, set high when the motor should go forward
+* @param rev A DigitalOut, set high when the motor should go backwards
+* @param set if the motor driver is able to do braking 0 false 1 true.
+*/
+        Motor(PinName pwm, PinName fwd, PinName rev, bool brakeable = false);
+  
+/** Set the speed of the motor 
+* 
+* @param speed The speed of the motor as a normalised value between -1.0 and 1.0.
+* @return the applied speed to the motor after checking to ensure motor doesn't switch from forward to reverse without stopping.
+*/
+        float speed(float speed);
+        
+/** Set the the motor to coast
+* 
+* @param void 
+* @return motor coasts until another instruction is recived.
+*/        
+  
+        void coast(void);
+
+/** Set the motor to dynamicaly brake
+* 
+* @param float 0 - 1.0 provides some control over how hard the motor brakes. 
+* @return duty applied to motor driver. -1 is error, motor driver can't brake.
+*/
+
+        float stop(float duty);
+/** return the current state of the motor
+*
+* @param void
+* @return state of motor, -1 to 1 is speed, -2 is braking, 2 is coasting. -3 is error. 
+*/
+        float state(void) const;
+        
+    protected:
+        mutable PwmOut _pwm;
+        mutable DigitalOut _fwd;
+        mutable DigitalOut _rev;
+        bool _brakeable; // cna the motor driver break
+        int _sign; //prevents throwing the motor from full foward to full reverse and stuff melting.
+ 
+};
+
+
+
+
+
+#endif