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Simplified microstepping
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@ladyada
ladyada committed Jan 3, 2011
1 parent c02162e commit 843cce2
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Showing 2 changed files with 79 additions and 197 deletions.
273 changes: 77 additions & 196 deletions AFMotor.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,14 @@ static uint8_t latch_state;

//#define MOTORDEBUG 1

#ifdef MICROSTEPPING
#if (MICROSTEPS == 8)
uint8_t microstepcurve[] = {0, 31, 63, 91, 127, 159, 191, 223, 255};
#elif (MICROSTEPS == 16)
uint8_t microstepcurve[] = {0, 15, 31, 47, 63, 79, 91, 111, 127, 143, 159, 175, 191, 207, 223, 239, 255};
#endif
#endif

AFMotorController::AFMotorController(void) {
}

Expand Down Expand Up @@ -413,8 +421,6 @@ void AF_Stepper::step(uint16_t steps, uint8_t dir, uint8_t style) {

uint8_t AF_Stepper::onestep(uint8_t dir, uint8_t style) {
uint8_t a, b, c, d;
uint8_t step;
uint8_t mstep = 0;
#ifdef MICROSTEPPING
uint8_t ocrb, ocra;
#endif
Expand All @@ -423,62 +429,15 @@ uint8_t AF_Stepper::onestep(uint8_t dir, uint8_t style) {
b = _BV(MOTOR2_A);
c = _BV(MOTOR1_B);
d = _BV(MOTOR2_B);

#ifdef MICROSTEPPING
#if defined(__AVR_ATmega8__) || \
defined(__AVR_ATmega48__) || \
defined(__AVR_ATmega88__) || \
defined(__AVR_ATmega168__) || \
defined(__AVR_ATmega328P__)
ocra = OCR2A;
ocrb = OCR2B;
#elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
ocra = OCR1A;
ocrb = OCR3C;
#else
#error "This chip is not supported!"
#endif

if (style == MICROSTEP) {
//TCCR2B = _BV(CS21);
}
#endif
} else if (steppernum == 2) {
a = _BV(MOTOR3_A);
b = _BV(MOTOR4_A);
c = _BV(MOTOR3_B);
d = _BV(MOTOR4_B);

#ifdef MICROSTEPPING
#if defined(__AVR_ATmega8__) || \
defined(__AVR_ATmega48__) || \
defined(__AVR_ATmega88__) || \
defined(__AVR_ATmega168__) || \
defined(__AVR_ATmega328P__)
ocra = OCR0A;
ocrb = OCR0B;
#elif defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
ocra = OCR4A;
ocrb = OCR3A;
#else
#error "This chip is not supported!"
#endif

if (style == MICROSTEP) {
//TCCR0B = _BV(CS00);
}
#endif

} else {
return 0;
}

#ifdef MOTORDEBUG
Serial.print("a = "); Serial.print(ocra, DEC);
Serial.print(" b = "); Serial.print(ocrb, DEC);
Serial.print("\t");
#endif

//Serial.print("step "); Serial.print(step, DEC); Serial.print("\t");
// next determine what sort of stepping procedure we're up to
if (style == SINGLE) {
Expand Down Expand Up @@ -533,134 +492,44 @@ uint8_t AF_Stepper::onestep(uint8_t dir, uint8_t style) {
ocrb = 255;
#endif
}
#ifdef MICROSTEPPING
else if (style == MICROSTEP) {

//Serial.print("Step #"); Serial.print(step/MICROSTEPS, DEC); Serial.print("\t");
#ifdef MICROSTEPPING
if (style == MICROSTEP) {
if (dir == FORWARD) {

// if at even step, make sure its 'odd'
if (! (step/MICROSTEPS) % 2) {
step = (step + MICROSTEPS) % (8*MICROSTEPS);
}

// fix hiccups from changing direction
if (((ocra == 255) && ((step/MICROSTEPS)%4 == 3)) ||
((ocrb == 255) && ((step/MICROSTEPS)%4 == 1))) {
step += 2*MICROSTEPS;
step %= 8*MICROSTEPS;
}

if ((step == MICROSTEPS) || (step == 5*MICROSTEPS)) {
// get the current microstep
if (ocrb == 255)
mstep = MICROSTEPS;
else
mstep = ocrb / (256UL / MICROSTEPS);
#ifdef MOTORDEBUG
Serial.print("uStep = "); Serial.print(mstep, DEC);
#endif
// ok now go to next step
mstep++;
mstep %= (MICROSTEPS+1);
if (mstep == MICROSTEPS)
ocrb = 255;
else
ocrb = mstep * (256UL / MICROSTEPS);
ocra = 255 - ocrb;
#ifdef MOTORDEBUG
Serial.print(" -> "); Serial.println(mstep, DEC);
#endif
if (mstep == MICROSTEPS)
step = (step + 2*MICROSTEPS) % (8*MICROSTEPS);
} else {
// get the current microstep
if (ocrb == 255)
mstep = MICROSTEPS;
else
mstep = ocrb / (256UL / MICROSTEPS);
#ifdef MOTORDEBUG
Serial.print("uStep = "); Serial.print(mstep, DEC);
#endif
// ok now go to next step
mstep += MICROSTEPS;
mstep %= (MICROSTEPS+1);
if (mstep == MICROSTEPS)
ocrb = 255;
else
ocrb = mstep * (256UL / MICROSTEPS);
ocra = 255 - ocrb;
#ifdef MOTORDEBUG
Serial.print(" +> "); Serial.println(mstep, DEC);
#endif
if (mstep == 0)
step = (step + 2*MICROSTEPS) % (8*MICROSTEPS);
}
currentstep++;
} else {
// BACKWARDS
currentstep--;
}

// fix hiccups from changing direction
if (((ocra == 255) && ((step/MICROSTEPS)%4 == 1)) ||
((ocrb == 255) && ((step/MICROSTEPS)%4 == 3))) {
step = (step + 6*MICROSTEPS);
step %= (8*MICROSTEPS);
}

// if at even step, make sure its 'odd'
if (! (step/MICROSTEPS % 2)) {
step = (step + 7*MICROSTEPS) % (8*MICROSTEPS);
}
if ((step == MICROSTEPS) || (step == 5*MICROSTEPS)) {
// get the current microstep
if (ocrb == 255)
mstep = MICROSTEPS;
else
mstep = ocrb / (256UL / MICROSTEPS);
#ifdef MOTORDEBUG
Serial.print(" uStep = "); Serial.print(mstep, DEC);
#endif
// ok now go to next step
mstep += MICROSTEPS;
mstep %= (MICROSTEPS+1);
if (mstep == MICROSTEPS)
ocrb = 255;
else
ocrb = mstep * (256UL / MICROSTEPS);
ocra = 255 - ocrb;
#ifdef MOTORDEBUG
Serial.print(" !> "); Serial.println(mstep, DEC);
#endif
if (mstep == 0)
step = (step + 6*MICROSTEPS) % (8*MICROSTEPS);
} else {
// get the current microstep
if (ocrb == 255)
mstep = MICROSTEPS;
else
mstep = ocrb / (256UL / MICROSTEPS);
#ifdef MOTORDEBUG
Serial.print("uStep = "); Serial.print(mstep, DEC);
#endif
// ok now go to next step
mstep++;
mstep %= (MICROSTEPS + 1);
if (mstep == MICROSTEPS)
ocrb = 255;
else
ocrb = mstep * (256UL / MICROSTEPS);
ocra = 255 - ocrb;
#ifdef MOTORDEBUG
Serial.print(" *> "); Serial.println(mstep, DEC);
#endif
if (mstep == MICROSTEPS)
step = (step + 6*MICROSTEPS) % (8*MICROSTEPS);
}
currentstep += MICROSTEPS*4;
currentstep %= MICROSTEPS*4;

ocra = ocrb = 0;
if ( (currentstep >= 0) && (currentstep < MICROSTEPS)) {
ocra = microstepcurve[MICROSTEPS - currentstep];
ocrb = microstepcurve[currentstep];
} else if ( (currentstep >= MICROSTEPS) && (currentstep < MICROSTEPS*2)) {
ocra = microstepcurve[currentstep - MICROSTEPS];
ocrb = microstepcurve[MICROSTEPS*2 - currentstep];
} else if ( (currentstep >= MICROSTEPS*2) && (currentstep < MICROSTEPS*3)) {
ocra = microstepcurve[MICROSTEPS*3 - currentstep];
ocrb = microstepcurve[currentstep - MICROSTEPS*2];
} else if ( (currentstep >= MICROSTEPS*3) && (currentstep < MICROSTEPS*4)) {
ocra = microstepcurve[currentstep - MICROSTEPS*3];
ocrb = microstepcurve[MICROSTEPS*4 - currentstep];
}
}
#endif // microstepping

currentstep += MICROSTEPS*4;
currentstep %= MICROSTEPS*4;
Serial.print("current step: "); Serial.println(currentstep, DEC);
//Serial.print("current step: "); Serial.println(currentstep, DEC);


//Serial.print(" -> step = "); Serial.print(step/MICROSTEPS, DEC); Serial.print("\t");
#ifdef MICROSTEPPING
//Serial.print(" pwmA = "); Serial.print(ocra, DEC);
//Serial.print(" pwmB = "); Serial.println(ocrb, DEC);

if (steppernum == 1) {
setPWM1(ocra);
Expand All @@ -669,41 +538,53 @@ uint8_t AF_Stepper::onestep(uint8_t dir, uint8_t style) {
setPWM3(ocra);
setPWM4(ocrb);
}
#endif

#endif // microstepping

// release all
latch_state &= ~a & ~b & ~c & ~d; // all motor pins to 0

//Serial.println(step, DEC);

switch (currentstep/(MICROSTEPS/2)) {
case 0:
latch_state |= a; // energize coil 1 only
break;
case 1:
latch_state |= a | b; // energize coil 1+2
break;
case 2:
latch_state |= b; // energize coil 2 only
break;
case 3:
latch_state |= b | c; // energize coil 2+3
break;
case 4:
latch_state |= c; // energize coil 3 only
break;
case 5:
latch_state |= c | d; // energize coil 3+4
break;
case 6:
latch_state |= d; // energize coil 4 only
break;
case 7:
latch_state |= d | a; // energize coil 1+4
break;
if (style == MICROSTEP) {
if ((currentstep >= 0) && (currentstep < MICROSTEPS))
latch_state |= a | b;
if ((currentstep >= MICROSTEPS) && (currentstep < MICROSTEPS*2))
latch_state |= b | c;
if ((currentstep >= MICROSTEPS*2) && (currentstep < MICROSTEPS*3))
latch_state |= c | d;
if ((currentstep >= MICROSTEPS*3) && (currentstep < MICROSTEPS*4))
latch_state |= d | a;
} else {
switch (currentstep/(MICROSTEPS/2)) {
case 0:
latch_state |= a; // energize coil 1 only
break;
case 1:
latch_state |= a | b; // energize coil 1+2
break;
case 2:
latch_state |= b; // energize coil 2 only
break;
case 3:
latch_state |= b | c; // energize coil 2+3
break;
case 4:
latch_state |= c; // energize coil 3 only
break;
case 5:
latch_state |= c | d; // energize coil 3+4
break;
case 6:
latch_state |= d; // energize coil 4 only
break;
case 7:
latch_state |= d | a; // energize coil 1+4
break;
}
}


MC.latch_tx();
return mstep;
return currentstep;
}

3 changes: 2 additions & 1 deletion AFMotor.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,8 @@
#define MICROSTEPPING 1

#ifdef MICROSTEPPING
#define MICROSTEPS 8 // 8, 16 & 32 are popular
#define MICROSTEPS 16 // 8 or 16

#endif

#define MOTOR12_64KHZ _BV(CS20) // no prescale
Expand Down

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