// Perform homing cycle to locate and set machine zero. Only '$H' executes this command.
// NOTE: There should be no motions in the buffer and Grbl must be in an idle state before
// executing the homing cycle. This prevents incorrect buffered plans after homing.
void MotionGoHome(void)
{
plan_init();
uint16_t limitStatus;
uint16_t stepCount;
sys.state = STATE_HOMING; // Set system state variable
// LIMIT_PCMSK &= ~LIMIT_MASK; // Disable hard limits pin change register for cycle duration
xLimitDetected = FALSE;
yLimitDetected = FALSE;
BSP_SetStepSize(X_AXIS, QUARTER);
BSP_SetStepSize(Y_AXIS, QUARTER);
BSP_SetStepSize(Z_AXIS, QUARTER);
settings.steps_per_mm[X_AXIS] = X_STEPS_MM(QUARTER_STEP);
settings.steps_per_mm[Y_AXIS] = Y_STEPS_MM(QUARTER_STEP);
settings.steps_per_mm[Z_AXIS] = Z_STEPS_MM(QUARTER_STEP);
// Find out if X or Y axis are at limit
limitStatus = mPORTCReadBits(xLimitInput.pin||yLimitInput.pin);
if(limitStatus)
{
if(limitStatus & xLimitInput.pin) // If Xat Limit
{
stepCount = 0;
BSP_Timer3Start(100);
OpenOC2(XS_PWM_ENA, (ReadPeriod3()>>1), ReadPeriod3()>>1);
BSP_AxisEnable(X_AXIS, NEGATIVE);
while((mPORTCReadBits(xLimitInput.pin)))
{
stepCount++;
steps_X = 0x1;
if(stepCount >= 20)
mPORTGToggleBits(xAxis.directionPin.pin);
}
BSP_AxisDisable(X_AXIS);
if(mPORTGReadBits(xAxis.directionPin.pin) == POSITIVE)
gcode.position[X_AXIS] = 215.000;
else
gcode.position[X_AXIS] =0;
}
if(limitStatus & yLimitInput.pin) // If Xat Limit
{
stepCount = 0;
BSP_Timer2Start(100);
OpenOC1(XS_PWM_ENA, (ReadPeriod2()>>1), ReadPeriod2()>>1);
BSP_AxisEnable(Y_AXIS, NEGATIVE);
while((mPORTCReadBits(yLimitInput.pin)))
{
stepCount++;
steps_Y = 0x1;
if(stepCount >= 20)
mPORTEToggleBits(yAxis.directionPin.pin);
}
if(mPORTEReadBits(xAxis.directionPin.pin) == POSITIVE)
gcode.position[Y_AXIS] = 215.000;
else
gcode.position[Y_AXIS] =0;
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// STEP 9. configure the CN interrupt handler
void __ISR(_CHANGE_NOTICE_VECTOR, ipl2) ChangeNotice_Handler(void)
{
unsigned int temp;
// clear the mismatch condition
temp = PORTReadBits(IOPORT_D, BIT_6);
// .. things to do .. toggle the led
mPORTDToggleBits(BIT_1);
mPORTEToggleBits(BIT_2);
// clear the interrupt flag
mCNClearIntFlag();
}
