scoutos / scout_avr / src / stepper.cpp @ a07a0b55
History | View | Annotate | Download (2.52 KB)
1 |
extern "C" |
---|---|
2 |
{ |
3 |
#include <avr/io.h> |
4 |
} |
5 |
#include "stepper.h" |
6 |
|
7 |
/* Stepper Motor:
|
8 |
* Provides interface to stepper motor.
|
9 |
* Can set direction. Outputs pulse to stepper upon call of step func
|
10 |
* Also provides variable speed sweep
|
11 |
*/
|
12 |
|
13 |
struct step_t {
|
14 |
unsigned int speed; // time between steps in ms for sweep. Mininum 40ms |
15 |
unsigned int sweep_us; //time between calls to sweep |
16 |
unsigned int time; |
17 |
int pos; // position in rotation. |
18 |
int dir; // direction. -1 CCW. 1 CW. 0 OFF |
19 |
int ccw;
|
20 |
int cw;
|
21 |
} volatile step;
|
22 |
|
23 |
|
24 |
func step_init(unsigned int call_us) |
25 |
{ |
26 |
/* set update time for sweep */
|
27 |
step.sweep_us = call_us; |
28 |
|
29 |
/* init pos and time to 0 */
|
30 |
step.pos = 0;
|
31 |
step.time = 0;
|
32 |
|
33 |
//set control pins as output
|
34 |
DDRD |= ((1<<S_STEP) | (1<<S_DIR)); |
35 |
DDRB |= ((1<<S_MS));
|
36 |
|
37 |
//initiate to full steps
|
38 |
PORTB &= (~(1<<S_MS));
|
39 |
|
40 |
//initiate the step pin to be low. stepper steps on low to high
|
41 |
PORTD &= (~(1<<S_STEP));
|
42 |
|
43 |
//return function pointer to sweep to be called ever sweep_us uS.
|
44 |
return &(step_sweep);
|
45 |
} |
46 |
|
47 |
/* set direction pin */
|
48 |
void step_dir(int dir) |
49 |
{ |
50 |
step.dir = dir; |
51 |
switch(dir)
|
52 |
{ |
53 |
case 1: |
54 |
PORTD |= (1<<S_DIR);
|
55 |
break;
|
56 |
case -1: |
57 |
PORTD &= (~(1<<S_DIR));
|
58 |
break;
|
59 |
} |
60 |
} |
61 |
|
62 |
void step_halfstep()
|
63 |
{ |
64 |
if(dir==0) return; //do not step if not enabled |
65 |
PORTB |= (1<<S_MS); //enable microstepping |
66 |
_asm_( |
67 |
"nop"
|
68 |
"nop"
|
69 |
"nop"
|
70 |
"nop"
|
71 |
);//wait 250 ns for microstepping to enable
|
72 |
PORTD |= (1<<S_STEP); //step once |
73 |
WAIT_US(1); //conform with step timing |
74 |
PORTD &= (~(1<<S_STEP)); //bring the step bin back down |
75 |
PORTB &= (~(1<<S_MS)); //disable microstepping |
76 |
if(dir==1) step.pos++; //keep track of position. 1/2 step so add/sub 1 |
77 |
else step.pos--;
|
78 |
} |
79 |
|
80 |
void step_fullstep()
|
81 |
{ |
82 |
if(dir==0) return; //do not step if not enabled |
83 |
PORTD |= (1<<S_STEP); //step once |
84 |
WAIT_US(2); //conform with step timing |
85 |
PORTD &= (~(1<<S_STEP)); //bring the step bin back down |
86 |
if(dir==1) step.pos+=2; // full step so add/sub 2 |
87 |
else step.pos-=2; |
88 |
} |
89 |
|
90 |
void step_flush()
|
91 |
{ |
92 |
PORTD &= (~(1<<S_STEP)); //bring the step bin back down |
93 |
} |
94 |
|
95 |
/* tick every speed ms in sweep mode */
|
96 |
void step_sweep_speed(unsigned int speed) |
97 |
{ |
98 |
if(speed<40) step.speed = 40000; |
99 |
else step.speed = speed*1000; |
100 |
} |
101 |
|
102 |
|
103 |
//ccw must be less than 0 and cw must be greater than 0
|
104 |
void step_sweep_bounds(int ccw, int cw) |
105 |
{ |
106 |
step.ccw = ccw; |
107 |
step.cw = cw; |
108 |
} |
109 |
|
110 |
void step_sweep()
|
111 |
{ |
112 |
step.time += sweep_us; |
113 |
if(step.time >= speed)
|
114 |
{ |
115 |
step_halfstep(); |
116 |
if((dir == 1) && (step.cw <= pos)) dir=-1; |
117 |
else if((dir == -1) && (step.ccw >= pos)) dir=1; |
118 |
} |
119 |
} |