aboutsummaryrefslogtreecommitdiff
path: root/Marlin/src/HAL/AVR/Servo.cpp
blob: 526352b77339662e20962ca251aa289944bee55d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

/**
 * servo.cpp - Interrupt driven Servo library for Arduino using 16 bit timers- Version 2
 * Copyright (c) 2009 Michael Margolis.  All right reserved.
 */

/**
 * A servo is activated by creating an instance of the Servo class passing the desired pin to the attach() method.
 * The servos are pulsed in the background using the value most recently written using the write() method
 *
 * Note that analogWrite of PWM on pins associated with the timer are disabled when the first servo is attached.
 * Timers are seized as needed in groups of 12 servos - 24 servos use two timers, 48 servos will use four.
 *
 * The methods are:
 *
 * Servo - Class for manipulating servo motors connected to Arduino pins.
 *
 * attach(pin)           - Attach a servo motor to an i/o pin.
 * attach(pin, min, max) - Attach to a pin, setting min and max values in microseconds
 *                         Default min is 544, max is 2400
 *
 * write()               - Set the servo angle in degrees. (Invalid angles —over MIN_PULSE_WIDTH— are treated as µs.)
 * writeMicroseconds()   - Set the servo pulse width in microseconds.
 * move(pin, angle)      - Sequence of attach(pin), write(angle), safe_delay(servo_delay[servoIndex]).
 *                         With DEACTIVATE_SERVOS_AFTER_MOVE it detaches after servo_delay[servoIndex].
 * read()                - Get the last-written servo pulse width as an angle between 0 and 180.
 * readMicroseconds()    - Get the last-written servo pulse width in microseconds.
 * attached()            - Return true if a servo is attached.
 * detach()              - Stop an attached servo from pulsing its i/o pin.
 */

#ifdef __AVR__

#include "../../inc/MarlinConfig.h"

#if HAS_SERVOS

#include <avr/interrupt.h>

#include "../shared/servo.h"
#include "../shared/servo_private.h"

static volatile int8_t Channel[_Nbr_16timers];              // counter for the servo being pulsed for each timer (or -1 if refresh interval)


/************ static functions common to all instances ***********************/

static inline void handle_interrupts(timer16_Sequence_t timer, volatile uint16_t* TCNTn, volatile uint16_t* OCRnA) {
  if (Channel[timer] < 0)
    *TCNTn = 0; // channel set to -1 indicated that refresh interval completed so reset the timer
  else {
    if (SERVO_INDEX(timer, Channel[timer]) < ServoCount && SERVO(timer, Channel[timer]).Pin.isActive)
      extDigitalWrite(SERVO(timer, Channel[timer]).Pin.nbr, LOW); // pulse this channel low if activated
  }

  Channel[timer]++;    // increment to the next channel
  if (SERVO_INDEX(timer, Channel[timer]) < ServoCount && Channel[timer] < SERVOS_PER_TIMER) {
    *OCRnA = *TCNTn + SERVO(timer, Channel[timer]).ticks;
    if (SERVO(timer, Channel[timer]).Pin.isActive)    // check if activated
      extDigitalWrite(SERVO(timer, Channel[timer]).Pin.nbr, HIGH); // it's an active channel so pulse it high
  }
  else {
    // finished all channels so wait for the refresh period to expire before starting over
    if (((unsigned)*TCNTn) + 4 < usToTicks(REFRESH_INTERVAL))    // allow a few ticks to ensure the next OCR1A not missed
      *OCRnA = (unsigned int)usToTicks(REFRESH_INTERVAL);
    else
      *OCRnA = *TCNTn + 4;  // at least REFRESH_INTERVAL has elapsed
    Channel[timer] = -1; // this will get incremented at the end of the refresh period to start again at the first channel
  }
}

#ifndef WIRING // Wiring pre-defines signal handlers so don't define any if compiling for the Wiring platform

  // Interrupt handlers for Arduino
  #ifdef _useTimer1
    SIGNAL(TIMER1_COMPA_vect) { handle_interrupts(_timer1, &TCNT1, &OCR1A); }
  #endif

  #ifdef _useTimer3
    SIGNAL(TIMER3_COMPA_vect) { handle_interrupts(_timer3, &TCNT3, &OCR3A); }
  #endif

  #ifdef _useTimer4
    SIGNAL(TIMER4_COMPA_vect) { handle_interrupts(_timer4, &TCNT4, &OCR4A); }
  #endif

  #ifdef _useTimer5
    SIGNAL(TIMER5_COMPA_vect) { handle_interrupts(_timer5, &TCNT5, &OCR5A); }
  #endif

#else // WIRING

  // Interrupt handlers for Wiring
  #ifdef _useTimer1
    void Timer1Service() { handle_interrupts(_timer1, &TCNT1, &OCR1A); }
  #endif
  #ifdef _useTimer3
    void Timer3Service() { handle_interrupts(_timer3, &TCNT3, &OCR3A); }
  #endif

#endif // WIRING

/****************** end of static functions ******************************/

void initISR(timer16_Sequence_t timer) {
  #ifdef _useTimer1
    if (timer == _timer1) {
      TCCR1A = 0;             // normal counting mode
      TCCR1B = _BV(CS11);     // set prescaler of 8
      TCNT1 = 0;              // clear the timer count
      #if defined(__AVR_ATmega8__) || defined(__AVR_ATmega128__)
        SBI(TIFR, OCF1A);      // clear any pending interrupts;
        SBI(TIMSK, OCIE1A);    // enable the output compare interrupt
      #else
        // here if not ATmega8 or ATmega128
        SBI(TIFR1, OCF1A);     // clear any pending interrupts;
        SBI(TIMSK1, OCIE1A);   // enable the output compare interrupt
      #endif
      #ifdef WIRING
        timerAttach(TIMER1OUTCOMPAREA_INT, Timer1Service);
      #endif
    }
  #endif

  #ifdef _useTimer3
    if (timer == _timer3) {
      TCCR3A = 0;             // normal counting mode
      TCCR3B = _BV(CS31);     // set prescaler of 8
      TCNT3 = 0;              // clear the timer count
      #ifdef __AVR_ATmega128__
        SBI(TIFR, OCF3A);     // clear any pending interrupts;
        SBI(ETIMSK, OCIE3A);  // enable the output compare interrupt
      #else
        SBI(TIFR3, OCF3A);   // clear any pending interrupts;
        SBI(TIMSK3, OCIE3A); // enable the output compare interrupt
      #endif
      #ifdef WIRING
        timerAttach(TIMER3OUTCOMPAREA_INT, Timer3Service);  // for Wiring platform only
      #endif
    }
  #endif

  #ifdef _useTimer4
    if (timer == _timer4) {
      TCCR4A = 0;             // normal counting mode
      TCCR4B = _BV(CS41);     // set prescaler of 8
      TCNT4 = 0;              // clear the timer count
      TIFR4 = _BV(OCF4A);     // clear any pending interrupts;
      TIMSK4 = _BV(OCIE4A);   // enable the output compare interrupt
    }
  #endif

  #ifdef _useTimer5
    if (timer == _timer5) {
      TCCR5A = 0;             // normal counting mode
      TCCR5B = _BV(CS51);     // set prescaler of 8
      TCNT5 = 0;              // clear the timer count
      TIFR5 = _BV(OCF5A);     // clear any pending interrupts;
      TIMSK5 = _BV(OCIE5A);   // enable the output compare interrupt
    }
  #endif
}

void finISR(timer16_Sequence_t timer) {
  // Disable use of the given timer
  #ifdef WIRING
    if (timer == _timer1) {
      CBI(
        #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2561__)
          TIMSK1
        #else
          TIMSK
        #endif
          , OCIE1A);    // disable timer 1 output compare interrupt
      timerDetach(TIMER1OUTCOMPAREA_INT);
    }
    else if (timer == _timer3) {
      CBI(
        #if defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2561__)
          TIMSK3
        #else
          ETIMSK
        #endif
          , OCIE3A);    // disable the timer3 output compare A interrupt
      timerDetach(TIMER3OUTCOMPAREA_INT);
    }
  #else // !WIRING
    // For arduino - in future: call here to a currently undefined function to reset the timer
    UNUSED(timer);
  #endif
}

#endif // HAS_SERVOS

#endif // __AVR__