ManuelW/grbl-LPC-CoreXY
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optimized for size and did some housekeeping

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This commit is contained in:
Simen Svale Skogsrud
2009-02-08 22:08:27 +01:00
parent 3e5e866115
commit 2992683c8d
5 changed files with 59 additions and 91 deletions
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30
stepper.c
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@ -32,6 +32,9 @@
#define TICKS_PER_MICROSECOND (F_CPU/1000000)
#define STEP_BUFFER_SIZE 100
// A marker used to notify the stepper handler of a pace change
#define PACE_CHANGE_MARKER 0xff
volatile uint8_t step_buffer[STEP_BUFFER_SIZE]; // A buffer for step instructions
volatile int step_buffer_head = 0;
volatile int step_buffer_tail = 0;
@ -43,25 +46,26 @@ uint8_t echo_steps = true;
void config_pace_timer(uint32_t microseconds);
// This timer interrupt is executed at the pace set with set_pace. It pops one instruction from
// This timer interrupt is executed at the pace set with st_buffer_pace. It pops one instruction from
// the step_buffer, executes it. Then it starts timer2 in order to reset the motor port after
// five microseconds.
SIGNAL(SIG_OUTPUT_COMPARE1A)
{
if (step_buffer_head != step_buffer_tail) {
if(step_buffer[step_buffer_tail] == 0xff) {
// If this is not a step-instruction, but a pace-marker: change pace
uint8_t popped = step_buffer[step_buffer_tail];
if(popped == PACE_CHANGE_MARKER) {
// This is not a step-instruction, but a pace-change-marker: change pace
config_pace_timer(next_pace);
next_pace = 0;
} else {
// Set the direction pins a nanosecond or two before you step the steppers
STEPPING_PORT = (STEPPING_PORT & ~DIRECTION_MASK) | (step_buffer[step_buffer_tail] & DIRECTION_MASK);
STEPPING_PORT = (STEPPING_PORT & ~DIRECTION_MASK) | (popped & DIRECTION_MASK);
// Then pulse the stepping pins
STEPPING_PORT = (STEPPING_PORT & ~STEP_MASK) | step_buffer[step_buffer_tail];
STEPPING_PORT = (STEPPING_PORT & ~STEP_MASK) | popped;
// Reset and start timer 2 which will reset the motor port after 5 microsecond
TCNT2 = 0; // reset counter
OCR2A = 5*TICKS_PER_MICROSECOND; // set the time
TIMSK2 |= (1<<OCIE2A); // enable interrupt
TCNT2 = 0; // reset counter
OCR2A = 5*TICKS_PER_MICROSECOND; // set the trigger time
TIMSK2 |= (1<<OCIE2A); // enable interrupt
}
// move the step buffer tail to the next instruction
step_buffer_tail = (step_buffer_tail + 1) % STEP_BUFFER_SIZE;
@ -101,7 +105,7 @@ void st_init()
sei();
// start off with a slow pace
// start off with a mellow pace
config_pace_timer(20000);
st_start();
}
@ -163,12 +167,12 @@ void st_buffer_pace(uint32_t microseconds)
{
// Do nothing if the pace in unchanged
if (current_pace == microseconds) { return; }
// If the one-element pace buffer is full, flush step buffer
if (next_pace != 0) {
st_synchronize();
// If the single-element pace "buffer" is full, sleep until it is popped
while (next_pace != 0) {
sleep_mode();
}
next_pace = microseconds;
st_buffer_step(0xff);
st_buffer_step(PACE_CHANGE_MARKER); // Place a pace-change marker in the step-buffer
}
uint8_t st_bit_for_stepper(int axis) {