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Revision d9b50611

IDd9b50611a8889856a5ab31a3dcdc6856e8f16c8b
Parent c874b753
Child fcddafaf

Added by Thomas Mullins almost 11 years ago

Fixed servo code to output correct signal

View differences:

paintboard/code/main.c
4 4
#include "sol.h"
5 5
#include <avr/io.h>
6 6
#include <avr/interrupt.h>
7
#include <util/delay.h>
7 8

  
8 9
#define TRACKING_ID 0x43
9 10
#define SERIAL_NUMBER 0x12
......
26 27

  
27 28
#define PAINT_DATA_LEN         13
28 29

  
29
#define METAL_DETECT           PD4
30
#define METAL_DETECT           PD5
30 31

  
31 32
uint8_t internal_index = 0;
32 33
uint8_t internal_data[PAINT_DATA_LEN] = {
......
105 106
  while (1)
106 107
  {
107 108
    internal_data[PAINT_INPUT_1] = !(!(_BV(METAL_DETECT) & PIND));
109
    if (internal_data[PAINT_INPUT_1]) {
110
      set_servo1(-128);
111
    } else {
112
      set_servo1(127);
113
    }
114
    servo_pulse();
108 115
    /* TODO geiger counter */
116
    _delay_ms(20);
109 117
  }
110 118
  return 0;
111 119
}
paintboard/code/servo.c
1 1
#include <avr/io.h>
2
#include "servo.h"
2
#include <avr/interrupt.h>
3 3
#include <stdlib.h>
4
#include "servo.h"
4 5

  
5 6
/*
6 7

  
7
servo controller. Timer0 is set to phase-correct PWM mode, with 32 prescaler.
8
Servo controller. Timer0 is set to fast PWM mode, with 64 prescaler. Outputs
9
are cleared on BOTTOM and set on compare match, and the compare values are set
10
to 255 minus the regular value. This way the timer can be stopped when it
11
overflows and the output will end up off, but will have been on for the correct
12
amount of time.
8 13

  
9 14
SERVO_PWM1: PD6 (Timer0)
10 15

  
......
12 17

  
13 18
*/
14 19

  
20
#define PRESCALER 64
21
#define MS_TO_TICKS(x) ((uint16_t)((x) * (F_CPU / 1000 / PRESCALER)))
22

  
23
#define MIN_TICKS MS_TO_TICKS(1)
24
#define MAX_TICKS MS_TO_TICKS(2)
25

  
26
static uint8_t angle_to_ticks(int8_t angle)
27
{
28
  return ((int16_t)angle + 128) * (MAX_TICKS - MIN_TICKS) / 256 + MIN_TICKS;
29
}
30

  
15 31
int8_t servo1_angle;
16 32
int8_t servo2_angle;
17 33

  
18 34
void servo_init()
19 35
{
36
  // WGM0 0b011 (fast pwm)
37
  // COM0A 0b11 (set OCR0A on compare match, clear on BOTTOM)
38
  // COM0B 0b11 (set OCR0B on compare match, clear on BOTTOM)
39
  // B is temporarily disabled grrrrr
40
  //TCCR0A = _BV(WGM01) | _BV(WGM00) | _BV(COM0A1) | _BV(COM0A0) | _BV(COM0B1)
41
  //    | _BV(COM0B0); TODO temporary
42
  TCCR0A = _BV(WGM01) | _BV(WGM00) | _BV(COM0A1) | _BV(COM0A0);
43
  TCCR0B = 0;
44

  
45
  // enable overflow interrupt
46
  TIMSK0 = _BV(TOIE0);
20 47

  
21
  // WGM0 0b001 (phase-correct PWM, 8-bit)
22
  // COM0A 0b10 (clear OCR0A on compare match, set on BOTTOM)
23
  // COM0B 0b10 (clear OCR0B on compare match, set on BOTTOM)
24
  // CS0 0b011 (32 prescaler)
25
  TCCR0A = _BV(WGM00) | _BV(COM0A1) |_BV(COM0B1);
26
  TCCR0B = _BV(CS01) | _BV(CS00);
27
  OCR0A = 0;
28
  OCR0B = 0;
29
  
30 48
  // set output pins
31
  DDRD |= _BV(PD5) | _BV(PD6);
49
  //DDRD |= _BV(PD5) | _BV(PD6); TODO temporary
50
  DDRD |= _BV(PD6);
32 51

  
33 52
  set_servo1(0);
34 53
  set_servo2(0);
35 54
}
36 55

  
56
void servo_pulse()
57
{
58
  // set limits, turn on outputs, and start timer
59

  
60
  OCR0A = 255 - angle_to_ticks(servo1_angle);
61
  OCR0B = 255 - angle_to_ticks(servo2_angle);
62
  TCNT0 = 0;
63

  
64
  // CS0 0b011 (64 prescaler)
65
  TCCR0B = _BV(CS01) | _BV(CS00);
66
}
67

  
37 68
void set_servo1(int8_t angle)
38 69
/* angle must be between -128 and 127 */
39 70
{
40 71
  servo1_angle = angle;
41
  OCR0A = (uint8_t)(angle + 128);
42 72
}
43 73

  
44 74
void set_servo2(int8_t angle)
45 75
/* angle must be between -128 and 127 */
46 76
{
47 77
  servo2_angle = angle;
48
  OCR0B = (uint8_t)(angle + 128);
49 78
}
50 79

  
51 80
int8_t get_servo1()
......
58 87
  return servo2_angle;
59 88
}
60 89

  
90
ISR(TIMER0_OVF_vect)
91
{
92
  // stop timer
93
  TCCR0B = 0;
94
}
paintboard/code/servo.h
2 2
#define _SERVO_H_
3 3

  
4 4
void servo_init();
5
void servo_pulse(); // should be called ~every 20ms
5 6
void set_servo1(int8_t angle);
6 7
void set_servo2(int8_t angle);
7 8
int8_t get_servo1();

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