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 | { |
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 | { |
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 | } |