ManuelW/grbl-LPC-CoreXY
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Fixed an issue with leaving the limit switches during a homing cycle.

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This commit is contained in:
Sonny Jeon 2012-10-08 17:39:53 -06:00
parent 4d8fd7f603
commit 6506b7a338
1 changed files with 16 additions and 20 deletions
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36
limits.c
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@ -35,8 +35,8 @@
void limits_init()
{
LIMIT_DDR &= ~(LIMIT_MASK); // Input pin
LIMIT_PORT |= (LIMIT_MASK); // Enable internal pull-up resistors for normal high
LIMIT_DDR &= ~(LIMIT_MASK); // Set as input pins
LIMIT_PORT |= (LIMIT_MASK); // Enable internal pull-up resistors. Normal high operation.
}
// Moves all specified axes in same specified direction (positive=true, negative=false)
@ -47,7 +47,8 @@ void limits_init()
// algorithm is written here. This also lets users hack and tune this code freely for
// their own particular needs without affecting the rest of Grbl.
// NOTE: Only the abort runtime command can interrupt this process.
static void homing_cycle(bool x_axis, bool y_axis, bool z_axis, int8_t pos_dir, float homing_rate)
static void homing_cycle(bool x_axis, bool y_axis, bool z_axis, int8_t pos_dir,
bool invert_pin, float homing_rate)
{
// Determine governing axes with finest step resolution per distance for the Bresenham
// algorithm. This solves the issue when homing multiple axes that have different
@ -92,17 +93,22 @@ static void homing_cycle(bool x_axis, bool y_axis, bool z_axis, int8_t pos_dir,
uint32_t step_rate = 0; // Tracks step rate. Initialized from 0 rate. (in step/min)
uint32_t trap_counter = MICROSECONDS_PER_ACCELERATION_TICK/2; // Acceleration trapezoid counter
uint8_t out_bits;
uint8_t limit_state;
for(;;) {
// Reset out bits. Both direction and step pins appropriately inverted and set.
out_bits = out_bits0;
// Get limit pin state.
limit_state = LIMIT_PIN;
if (invert_pin) { limit_state ^= LIMIT_MASK; } // If leaving switch, invert to move.
// Set step pins by Bresenham line algorithm. If limit switch reached, disable and
// flag for completion.
if (x_axis) {
counter_x += steps[X_AXIS];
if (counter_x > 0) {
if (LIMIT_PIN & (1<<X_LIMIT_BIT)) { out_bits ^= (1<<X_STEP_BIT); }
if (limit_state & (1<<X_LIMIT_BIT)) { out_bits ^= (1<<X_STEP_BIT); }
else { x_axis = false; }
counter_x -= step_event_count;
}
@ -110,7 +116,7 @@ static void homing_cycle(bool x_axis, bool y_axis, bool z_axis, int8_t pos_dir,
if (y_axis) {
counter_y += steps[Y_AXIS];
if (counter_y > 0) {
if (LIMIT_PIN & (1<<Y_LIMIT_BIT)) { out_bits ^= (1<<Y_STEP_BIT); }
if (limit_state & (1<<Y_LIMIT_BIT)) { out_bits ^= (1<<Y_STEP_BIT); }
else { y_axis = false; }
counter_y -= step_event_count;
}
@ -118,7 +124,7 @@ static void homing_cycle(bool x_axis, bool y_axis, bool z_axis, int8_t pos_dir,
if (z_axis) {
counter_z += steps[Z_AXIS];
if (counter_z > 0) {
if (LIMIT_PIN & (1<<Z_LIMIT_BIT)) { out_bits ^= (1<<Z_STEP_BIT); }
if (limit_state & (1<<Z_LIMIT_BIT)) { out_bits ^= (1<<Z_STEP_BIT); }
else { z_axis = false; }
counter_z -= step_event_count;
}
@ -152,34 +158,24 @@ static void homing_cycle(bool x_axis, bool y_axis, bool z_axis, int8_t pos_dir,
static void approach_limit_switch(bool x, bool y, bool z)
{
homing_cycle(x, y, z, true, settings.default_seek_rate);
homing_cycle(x, y, z, true, false, settings.default_seek_rate);
}
static void leave_limit_switch(bool x, bool y, bool z) {
homing_cycle(x, y, z, false, settings.default_feed_rate);
homing_cycle(x, y, z, false, true, settings.default_feed_rate);
}
void limits_go_home()
{
plan_synchronize(); // Empty all motions in buffer.
// TODO: Need to come up a better way to manage and set limit switches.
uint8_t original_limit_state = LIMIT_PIN; // Store the current limit switch state
// Jog all axes toward home to engage their limit switches.
approach_limit_switch(false, false, true); // First home the z axis
approach_limit_switch(true, true, false); // Then home the x and y axis
delay_ms(LIMIT_DEBOUNCE); // Delay to debounce signal before leaving limit switches
// Xor previous and current limit switch state to determine which were high then but have become
// low now. These are the actual installed limit switches.
uint8_t limit_switches_present = (original_limit_state ^ LIMIT_PIN) & LIMIT_MASK;
// Now carefully leave the limit switches
leave_limit_switch(
limit_switches_present & (1<<X_LIMIT_BIT),
limit_switches_present & (1<<Y_LIMIT_BIT),
limit_switches_present & (1<<Z_LIMIT_BIT));
leave_limit_switch(true,true,true);
delay_ms(LIMIT_DEBOUNCE); // Delay to debounce signal before exiting routine
}