motor drive libary to use speed control, coasting and dynamic braking. NOTE, dynamic braking my result in large currents. this may or may not set the motor driver on fire/break it/other undesired effects. so read the data sheet folks.

Dependents:   motordrivertestprogram Initialmbedrobotprogram mbedrobot ipod ... more

Committer:
littlexc
Date:
Thu Nov 11 15:32:55 2010 +0000
Revision:
1:3da7302dc9ae
Parent:
0:edc152f119b7
Child:
2:2dc873322032
this libary prevents throwing the motor from full foward to full reverse. to change direction, the motor must first come to a full stop, ie, coast, break or set speed to = 0.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
littlexc 1:3da7302dc9ae 1 /*motor driver libary modified from the following libary,
littlexc 1:3da7302dc9ae 2 *
littlexc 1:3da7302dc9ae 3 * mbed simple H-bridge motor controller
littlexc 1:3da7302dc9ae 4 * Copyright (c) 2007-2010, sford
littlexc 1:3da7302dc9ae 5 *
littlexc 1:3da7302dc9ae 6 * by Christopher Hasler.
littlexc 1:3da7302dc9ae 7 *
littlexc 1:3da7302dc9ae 8 * from sford's libary,
littlexc 1:3da7302dc9ae 9 *
littlexc 1:3da7302dc9ae 10 * Permission is hereby granted, free of charge, to any person obtaining a copy
littlexc 1:3da7302dc9ae 11 * of this software and associated documentation files (the "Software"), to deal
littlexc 1:3da7302dc9ae 12 * in the Software without restriction, including without limitation the rights
littlexc 1:3da7302dc9ae 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
littlexc 1:3da7302dc9ae 14 * copies of the Software, and to permit persons to whom the Software is
littlexc 1:3da7302dc9ae 15 * furnished to do so, subject to the following conditions:
littlexc 1:3da7302dc9ae 16 *
littlexc 1:3da7302dc9ae 17 * The above copyright notice and this permission notice shall be included in
littlexc 1:3da7302dc9ae 18 * all copies or substantial portions of the Software.
littlexc 1:3da7302dc9ae 19 *
littlexc 1:3da7302dc9ae 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
littlexc 1:3da7302dc9ae 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
littlexc 1:3da7302dc9ae 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
littlexc 1:3da7302dc9ae 23 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
littlexc 1:3da7302dc9ae 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
littlexc 1:3da7302dc9ae 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
littlexc 1:3da7302dc9ae 26 * THE SOFTWARE.
littlexc 1:3da7302dc9ae 27 */
littlexc 0:edc152f119b7 28
littlexc 0:edc152f119b7 29 #include "motordriver.h"
littlexc 1:3da7302dc9ae 30
littlexc 0:edc152f119b7 31 #include "mbed.h"
littlexc 1:3da7302dc9ae 32
littlexc 0:edc152f119b7 33 Motor::Motor(PinName pwm, PinName fwd, PinName rev, int brakeable):
littlexc 0:edc152f119b7 34 _pwm(pwm), _fwd(fwd), _rev(rev) {
littlexc 0:edc152f119b7 35
littlexc 0:edc152f119b7 36 // Set initial condition of PWM
littlexc 0:edc152f119b7 37 _pwm.period(0.001);
littlexc 0:edc152f119b7 38 _pwm = 0;
littlexc 0:edc152f119b7 39
littlexc 0:edc152f119b7 40 // Initial condition of output enables
littlexc 0:edc152f119b7 41 _fwd = 0;
littlexc 0:edc152f119b7 42 _rev = 0;
littlexc 1:3da7302dc9ae 43
littlexc 0:edc152f119b7 44 //set if the motor dirver is capable of braking. (addition)
littlexc 0:edc152f119b7 45 Brakeable= brakeable;
littlexc 1:3da7302dc9ae 46 sign = 0;//i.e nothing.
littlexc 0:edc152f119b7 47 }
littlexc 1:3da7302dc9ae 48
littlexc 0:edc152f119b7 49 void Motor::speed(float speed) {
littlexc 1:3da7302dc9ae 50 if (sign == 0) {
littlexc 1:3da7302dc9ae 51 _fwd = (speed > 0.0);
littlexc 1:3da7302dc9ae 52 _rev = (speed < 0.0);
littlexc 1:3da7302dc9ae 53 _pwm = abs(speed);
littlexc 1:3da7302dc9ae 54 } else if (sign == 1) {
littlexc 1:3da7302dc9ae 55 if (speed < 0) {
littlexc 1:3da7302dc9ae 56 _fwd = (speed > 0.0);
littlexc 1:3da7302dc9ae 57 _rev = (speed < 0.0);
littlexc 1:3da7302dc9ae 58 _pwm = 0;
littlexc 1:3da7302dc9ae 59 } else {
littlexc 1:3da7302dc9ae 60 _fwd = (speed > 0.0);
littlexc 1:3da7302dc9ae 61 _rev = (speed < 0.0);
littlexc 1:3da7302dc9ae 62 _pwm = abs(speed);
littlexc 1:3da7302dc9ae 63 }
littlexc 1:3da7302dc9ae 64 } else if (sign == -1) {
littlexc 1:3da7302dc9ae 65 if (speed > 0) {
littlexc 1:3da7302dc9ae 66 _fwd = (speed > 0.0);
littlexc 1:3da7302dc9ae 67 _rev = (speed < 0.0);
littlexc 1:3da7302dc9ae 68 _pwm = 0;
littlexc 1:3da7302dc9ae 69 } else {
littlexc 1:3da7302dc9ae 70 _fwd = (speed > 0.0);
littlexc 1:3da7302dc9ae 71 _rev = (speed < 0.0);
littlexc 1:3da7302dc9ae 72 _pwm = abs(speed);
littlexc 1:3da7302dc9ae 73 }
littlexc 1:3da7302dc9ae 74 }
littlexc 1:3da7302dc9ae 75 if (speed > 0)
littlexc 1:3da7302dc9ae 76 sign = 1;
littlexc 1:3da7302dc9ae 77 else if (speed < 0) {
littlexc 1:3da7302dc9ae 78 sign = -1;
littlexc 1:3da7302dc9ae 79 } else if (speed == 0) {
littlexc 1:3da7302dc9ae 80 sign = 0;
littlexc 1:3da7302dc9ae 81 }
littlexc 1:3da7302dc9ae 82
littlexc 0:edc152f119b7 83 }
littlexc 0:edc152f119b7 84 // (additions)
littlexc 0:edc152f119b7 85 void Motor::coast(void) {
littlexc 0:edc152f119b7 86 _fwd = 0;
littlexc 0:edc152f119b7 87 _rev = 0;
littlexc 0:edc152f119b7 88 _pwm = 0;
littlexc 1:3da7302dc9ae 89 sign = 0;
littlexc 0:edc152f119b7 90 }
littlexc 0:edc152f119b7 91
littlexc 0:edc152f119b7 92 void Motor::stop(void) {
littlexc 0:edc152f119b7 93 if (Brakeable == 1) {
littlexc 0:edc152f119b7 94 _fwd = 1;
littlexc 0:edc152f119b7 95 _rev = 1;
littlexc 0:edc152f119b7 96 _pwm = 0.5;
littlexc 1:3da7302dc9ae 97 sign = 0;
littlexc 1:3da7302dc9ae 98 } else
littlexc 1:3da7302dc9ae 99 return;
littlexc 0:edc152f119b7 100 }
littlexc 1:3da7302dc9ae 101
littlexc 0:edc152f119b7 102 /*
littlexc 0:edc152f119b7 103 test code, this demonstrates working motor drivers.
littlexc 1:3da7302dc9ae 104
littlexc 1:3da7302dc9ae 105 Motor A(p22, p6, p5, 1); // pwm, fwd, rev, can break
littlexc 0:edc152f119b7 106 Motor B(p21, p7, p8, 1); // pwm, fwd, rev, can break
littlexc 0:edc152f119b7 107 int main() {
littlexc 0:edc152f119b7 108 for (float s=-1.0; s < 1.0 ; s += 0.01) {
littlexc 1:3da7302dc9ae 109 A.speed(s);
littlexc 1:3da7302dc9ae 110 B.speed(s);
littlexc 0:edc152f119b7 111 wait(0.02);
littlexc 0:edc152f119b7 112 }
littlexc 0:edc152f119b7 113 A.stop();
littlexc 0:edc152f119b7 114 B.stop();
littlexc 0:edc152f119b7 115 wait(1);
littlexc 0:edc152f119b7 116 A.coast();
littlexc 0:edc152f119b7 117 B.coast();
littlexc 0:edc152f119b7 118 }
littlexc 0:edc152f119b7 119 */