root / scout_avr / src / stepper.cpp @ 958699af
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| 1 | a07a0b55 | Julian Binder | extern "C" |
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| 2 | {
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| 3 | #include <avr/io.h> |
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| 4 | 85dff67b | Julian Binder | #include <util/delay.h> |
| 5 | a07a0b55 | Julian Binder | } |
| 6 | #include "stepper.h" |
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| 7 | |||
| 8 | /* Stepper Motor:
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| 9 | * Provides interface to stepper motor.
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| 10 | * Can set direction. Outputs pulse to stepper upon call of step func
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| 11 | * Also provides variable speed sweep
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| 12 | */
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| 13 | |||
| 14 | struct step_t {
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| 15 | int pos; // position in rotation. |
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| 16 | int dir; // direction. -1 CCW. 1 CW. 0 OFF |
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| 17 | 2853d46b | Tom Mullins | int step_size; // amount to add to position each step |
| 18 | a07a0b55 | Julian Binder | int ccw;
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| 19 | int cw;
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| 20 | 2853d46b | Tom Mullins | } step; |
| 21 | a07a0b55 | Julian Binder | |
| 22 | |||
| 23 | 2853d46b | Tom Mullins | void step_init()
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| 24 | a07a0b55 | Julian Binder | {
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| 25 | 2853d46b | Tom Mullins | /* init pos and dir to 0 */
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| 26 | a07a0b55 | Julian Binder | step.pos = 0;
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| 27 | 85dff67b | Julian Binder | step.dir = 0;
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| 28 | a07a0b55 | Julian Binder | |
| 29 | //set control pins as output
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| 30 | DDRD |= ((1<<S_STEP) | (1<<S_DIR)); |
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| 31 | DDRB |= ((1<<S_MS));
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| 32 | |||
| 33 | //initiate to full steps
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| 34 | 2853d46b | Tom Mullins | step_set_size(STEP_WHOLE); |
| 35 | a07a0b55 | Julian Binder | |
| 36 | //initiate the step pin to be low. stepper steps on low to high
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| 37 | PORTD &= (~(1<<S_STEP));
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| 38 | 2853d46b | Tom Mullins | } |
| 39 | a07a0b55 | Julian Binder | |
| 40 | 2853d46b | Tom Mullins | void step_set_size(char size) |
| 41 | {
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| 42 | if (size == STEP_WHOLE)
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| 43 | {
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| 44 | PORTB &= ~_BV(S_MS); |
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| 45 | step.step_size = 2;
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| 46 | } |
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| 47 | else
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| 48 | {
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| 49 | PORTB |= _BV(S_MS); |
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| 50 | step.step_size = 1;
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| 51 | } |
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| 52 | a07a0b55 | Julian Binder | } |
| 53 | |||
| 54 | /* set direction pin */
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| 55 | void step_dir(int dir) |
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| 56 | {
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| 57 | step.dir = dir; |
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| 58 | switch(dir)
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| 59 | {
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| 60 | case 1: |
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| 61 | 2853d46b | Tom Mullins | PORTD |= (1<<S_DIR);
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| 62 | a07a0b55 | Julian Binder | break;
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| 63 | case -1: |
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| 64 | 2853d46b | Tom Mullins | PORTD &= (~(1<<S_DIR));
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| 65 | a07a0b55 | Julian Binder | break;
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| 66 | } |
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| 67 | } |
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| 68 | |||
| 69 | 2853d46b | Tom Mullins | void step_do_step()
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| 70 | a07a0b55 | Julian Binder | {
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| 71 | 85dff67b | Julian Binder | if(step.dir==0) return; //do not step if not enabled |
| 72 | a07a0b55 | Julian Binder | PORTD |= (1<<S_STEP); //step once |
| 73 | 85dff67b | Julian Binder | _delay_us(1); //conform with step timing |
| 74 | a07a0b55 | Julian Binder | PORTD &= (~(1<<S_STEP)); //bring the step bin back down |
| 75 | 2853d46b | Tom Mullins | if(step.dir==1) step.pos += step.step_size; |
| 76 | else step.pos -= step.step_size;
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| 77 | a07a0b55 | Julian Binder | } |
| 78 | |||
| 79 | void step_flush()
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| 80 | {
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| 81 | PORTD &= (~(1<<S_STEP)); //bring the step bin back down |
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| 82 | } |
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| 83 | |||
| 84 | //ccw must be less than 0 and cw must be greater than 0
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| 85 | void step_sweep_bounds(int ccw, int cw) |
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| 86 | {
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| 87 | step.ccw = ccw; |
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| 88 | step.cw = cw; |
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| 89 | } |
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| 90 | |||
| 91 | void step_sweep()
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| 92 | {
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| 93 | 2853d46b | Tom Mullins | step_do_step(); |
| 94 | if((step.dir == 1) && (step.cw <= step.pos)) step_dir(-1); |
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| 95 | else if((step.dir == -1) && (step.ccw >= step.pos)) step_dir(1); |
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| 96 | a07a0b55 | Julian Binder | } |