Async_4pin_Stepper.cpp

00001 /* Asynchronous Stepper with 4-pin output
00002  *
00003  * Written by Simon Krogedal
00004  * 31/05/2021
00005  * Team 9 4th Year project
00006  * 
00007  * for NUCLEO-F401RE
00008  * 
00009  * Version 0.1
00010  *
00011  */
00012  
00013 #include "Async_4pin_Stepper.h "
00014 
00015 // Constructor takes 4 pins and a steps/rev in float presicion
00016 Async_4pin_Stepper::Async_4pin_Stepper( PinName StepperPin1,
00017                                         PinName StepperPin2,
00018                                         PinName StepperPin3,
00019                                         PinName StepperPin4,
00020                                         float   StepsPerRev) :
00021                                         
00022                                         output(StepperPin1,
00023                                                StepperPin2,
00024                                                StepperPin3,
00025                                                StepperPin4)
00026 {
00027     SPR = StepsPerRev;
00028     setSpeed(500);
00029     currentPos = 0;
00030     relax();
00031 }
00032 
00033 void Async_4pin_Stepper::setZeroPos() {currentPos = 0;}
00034 
00035 void Async_4pin_Stepper::setSpeed(int speed) {
00036     if(speed > 0) {
00037         speed_ = speed;
00038         stepInterval = 1.0/speed;
00039     }
00040     else {
00041         speed_ = 0;
00042         stepInterval = 0;
00043     }
00044 }
00045 
00046 int Async_4pin_Stepper::getPos() {return currentPos;}
00047 int Async_4pin_Stepper::getTarget() {return targetPos;}
00048 int Async_4pin_Stepper::getSpeed() {return speed_;}
00049 int Async_4pin_Stepper::distanceToGo() {return targetPos-currentPos;}
00050 
00051 void Async_4pin_Stepper::step(int step) {
00052     switch (step & 0x7) {
00053         case 0:    // 1000
00054             output = 0b0001;
00055             break;
00056             
00057         case 1:    // 1010
00058             output = 0b0101;
00059             break;
00060             
00061         case 2:    // 0010
00062             output = 0b0100;
00063             break;
00064             
00065         case 3:    // 0110
00066             output = 0b0110;
00067             break;
00068             
00069         case 4:    // 0100
00070             output = 0b0010;
00071             break;
00072             
00073         case 5:    //0101
00074             output = 0b1010;
00075             break;
00076             
00077         case 6:    // 0001
00078             output = 0b1000;
00079             break;
00080             
00081         case 7:    //1001
00082             output = 0b1001;
00083             break;
00084     }
00085 }
00086 
00087 void Async_4pin_Stepper::stepOnceCCW() {
00088     // Update current position
00089     currentPos++;
00090     // Step to new position
00091     step(currentPos);
00092 }
00093 
00094 void Async_4pin_Stepper::stepOnceCW() {
00095     // Update current position
00096     currentPos--;
00097     // Step to new position
00098     step(currentPos);
00099 }
00100 
00101 void Async_4pin_Stepper::setTarget(int target) {targetPos = target;}
00102 
00103 void Async_4pin_Stepper::goToTarget() {
00104     // Check if at target or standstill
00105     if(!distanceToGo() || !stepInterval || running)
00106         return;
00107     else { // Attach ticker to callback function
00108         ticker.attach(callback(this, &Async_4pin_Stepper::stepCB), stepInterval);
00109         running = true;
00110     }
00111 }
00112 
00113 void Async_4pin_Stepper::stepCB() {
00114     // check error value for driction
00115     int error = distanceToGo();
00116     if(error == 0) {
00117         ticker.detach();
00118         running = false;
00119     }
00120     else if(error > 0)
00121         stepOnceCCW();
00122     else
00123         stepOnceCW();
00124 }        
00125 
00126 void Async_4pin_Stepper::relax() {output = 0;}
00127 bool Async_4pin_Stepper::isRunning() {return running;}
00128 void Async_4pin_Stepper::stop() {ticker.detach();}