HBridgeDCMotor.cpp

00001 #include "HBridgeDCMotor.h"
00002 
00003 HBridgeDCMotor::HBridgeDCMotor(PinName gh_a, PinName gl_a, PinName gh_b, PinName gl_b) {
00004     GH_A = new PwmOut(gh_a);
00005     GL_A = new PwmOut(gl_a);
00006     GH_B = new PwmOut(gh_b);
00007     GL_B = new PwmOut(gl_b);
00008     independentGates = true;
00009     configure(1e-3, 20e3, 0.1, -0.1);
00010     init();
00011 }
00012 
00013 HBridgeDCMotor::HBridgeDCMotor(PinName gh_a, PinName gh_b) {
00014     GH_A = new PwmOut(gh_a);
00015     GL_A = NULL;
00016     GH_B = new PwmOut(gh_b);
00017     GL_B = NULL;
00018     independentGates = false;
00019     configure(1e-3, 20e3, 0.1, -0.1);
00020     init();
00021 }
00022 
00023 void HBridgeDCMotor::init() {
00024     dutyCycle = tempDutyCycle = 0;
00025 }
00026 
00027 void HBridgeDCMotor::configure(float sampleTime, float switchingFrequency, float rampUpTime, float rampDownTime) {
00028     if (sampleTime < 1e-6)
00029         sampleTime = 1e-3;
00030     if (switchingFrequency < 100)
00031         switchingFrequency = 20e3;
00032     if (rampUpTime < 1)
00033         rampUpTime = 5;
00034     if (rampDownTime < 1)
00035         rampDownTime = 5;
00036     this->sampleTime = sampleTime;
00037     switchingPeriod = 1.0 / switchingFrequency;
00038     GH_A->period(switchingPeriod);
00039     rl.setLimits(1.0/rampUpTime, -1.0/rampDownTime, 0, sampleTime);
00040 }
00041 
00042 void HBridgeDCMotor::adjustDutyCycle() {
00043     dutyCycle = rl.out(tempDutyCycle);
00044     if (dutyCycle >= 0 && dutyCycle <= 1) {
00045         GH_B->write(0);
00046         if(independentGates) {
00047             GL_B->write(1);
00048             GL_A->write(0);
00049         }
00050         GH_A->write(dutyCycle);
00051     } else if (dutyCycle >= -1 && dutyCycle < 0) { // opposite direction
00052         GH_A->write(0);
00053         if(independentGates) {
00054             GL_A->write(1);
00055             GL_B->write(0);
00056         }
00057         GH_B->write(-dutyCycle);
00058     } else {
00059         coast();
00060     }
00061 }
00062 
00063 void HBridgeDCMotor::setDutyCycle(float dc) {
00064     if (dc >= -1 && dc <= 1) {
00065         ticker.attach(this, &HBridgeDCMotor::adjustDutyCycle, sampleTime);
00066         tempDutyCycle = dc;
00067     } else {
00068         coast();
00069     }
00070 }
00071 
00072 void HBridgeDCMotor::coast() {
00073     GH_A->write(0);
00074     GH_B->write(0);
00075     if(independentGates) {
00076         GL_A->write(0);
00077         GL_B->write(0);
00078     }
00079     dutyCycle = tempDutyCycle = 0;
00080     rl.reset();
00081     ticker.detach();
00082 }
00083 
00084 float HBridgeDCMotor::getDutyCycle() {
00085     return dutyCycle;
00086 }