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authorDavid A. Mellis <d.mellis@arduino.cc>2009-11-07 17:54:56 +0000
committerDavid A. Mellis <d.mellis@arduino.cc>2009-11-07 17:54:56 +0000
commit6005c59ad03446153c66a991f01ac91c31d98dac (patch)
tree4c599359fd35066a81b8b9fe99042e325c03c6ed /libraries/Servo/Servo.cpp
parent584dece7b0c982de8731f7400c94b5034aef89e7 (diff)
Moving libraries out of arduino platform / core directory and to top-level.
Diffstat (limited to 'libraries/Servo/Servo.cpp')
-rwxr-xr-xlibraries/Servo/Servo.cpp268
1 files changed, 0 insertions, 268 deletions
diff --git a/libraries/Servo/Servo.cpp b/libraries/Servo/Servo.cpp
deleted file mode 100755
index 9f58d64..0000000
--- a/libraries/Servo/Servo.cpp
+++ /dev/null
@@ -1,268 +0,0 @@
-/*
- Servo.cpp - Interrupt driven Servo library for Arduino using 16 bit timers- Version 2
- Copyright (c) 2009 Michael Margolis. All right reserved.
-
- This library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- This library 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with this library; if not, write to the Free Software
- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/*
-
- 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 ) - Attaches a servo motor to an i/o pin.
- attach(pin, min, max ) - Attaches to a pin setting min and max values in microseconds
- default min is 544, max is 2400
-
- write() - Sets the servo angle in degrees. (invalid angle that is valid as pulse in microseconds is treated as microseconds)
- writeMicroseconds() - Sets the servo pulse width in microseconds
- read() - Gets the last written servo pulse width as an angle between 0 and 180.
- readMicroseconds() - Gets the last written servo pulse width in microseconds. (was read_us() in first release)
- attached() - Returns true if there is a servo attached.
- detach() - Stops an attached servos from pulsing its i/o pin.
-
-*/
-
-#include <avr/interrupt.h>
-#include <WProgram.h>
-
-
-#include "Servo.h"
-
-#define TICKS_PER_uS (clockCyclesPerMicrosecond() / 8) // number of timer ticks per microsecond with prescale of 8
-
-#define SERVOS_PER_TIMER 12 // the maximum number of servos controlled by one timer
-#define TRIM_DURATION (SERVOS_PER_TIMER/2) // compensation ticks to trim adjust for digitalWrite delays
-
-#define NBR_TIMERS (MAX_SERVOS / SERVOS_PER_TIMER)
-
-static servo_t servos[MAX_SERVOS]; // static array of servo structures
-static volatile int8_t Channel[NBR_TIMERS]; // counter for the servo being pulsed for each timer (or -1 if refresh interval)
-#if defined(__AVR_ATmega1280__)
-typedef enum { _timer5, _timer1, _timer3, _timer4 } servoTimer_t; // this is the sequence for timer utilization on mega
-#else
-typedef enum { _timer1 } servoTimer_t; // this is the sequence for timer utilization on other controllers
-#endif
-
-uint8_t ServoCount = 0; // the total number of attached servos
-
-// convenience macros
-#define SERVO_INDEX_TO_TIMER(_servo_nbr) ((servoTimer_t)(_servo_nbr / SERVOS_PER_TIMER)) // returns the timer controlling this servo
-#define SERVO_INDEX_TO_CHANNEL(_servo_nbr) (_servo_nbr % SERVOS_PER_TIMER) // returns the index of the servo on this timer
-#define SERVO_INDEX(_timer,_channel) ((_timer*SERVOS_PER_TIMER) + _channel) // macro to access servo index by timer and channel
-#define SERVO(_timer,_channel) (servos[SERVO_INDEX(_timer,_channel)]) // macro to access servo class by timer and channel
-
-#define SERVO_MIN() (MIN_PULSE_WIDTH - this->min * 4) // minimum value in uS for this servo
-#define SERVO_MAX() (MAX_PULSE_WIDTH - this->max * 4) // maximum value in uS for this servo
-
-/************ static functions common to all instances ***********************/
-
-static inline void handle_interrupts(servoTimer_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 == true )
- digitalWrite( 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 == true) // check if activated
- digitalWrite( SERVO(timer,Channel[timer]).Pin.nbr,HIGH); // its 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 < (((unsigned int)REFRESH_INTERVAL * TICKS_PER_uS) + 4) ) // allow a few ticks to ensure the next OCR1A not missed
- *OCRnA = (unsigned int)REFRESH_INTERVAL * TICKS_PER_uS;
- 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
- }
-}
-
-SIGNAL (TIMER1_COMPA_vect)
-{
- handle_interrupts(_timer1, &TCNT1, &OCR1A);
-}
-
-#if defined(__AVR_ATmega1280__)
-SIGNAL (TIMER3_COMPA_vect)
-{
- handle_interrupts(_timer3, &TCNT3, &OCR3A);
-}
-SIGNAL (TIMER4_COMPA_vect)
-{
- handle_interrupts(_timer4, &TCNT4, &OCR4A);
-}
-SIGNAL (TIMER5_COMPA_vect)
-{
- handle_interrupts(_timer5, &TCNT5, &OCR5A);
-}
-#endif
-
-static void initISR(servoTimer_t timer)
-{
- 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__)
- TIFR |= _BV(OCF1A); // clear any pending interrupts;
- TIMSK |= _BV(OCIE1A) ; // enable the output compare interrupt
-#else
- TIFR1 |= _BV(OCF1A); // clear any pending interrupts;
- TIMSK1 |= _BV(OCIE1A) ; // enable the output compare interrupt
-#endif
- }
-#if defined(__AVR_ATmega1280__)
- else if(timer == _timer3) {
- TCCR3A = 0; // normal counting mode
- TCCR3B = _BV(CS31); // set prescaler of 8
- TCNT3 = 0; // clear the timer count
- TIFR3 = _BV(OCF3A); // clear any pending interrupts;
- TIMSK3 = _BV(OCIE3A) ; // enable the output compare interrupt
- }
- else 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
- }
- else 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
-}
-
-static boolean isTimerActive(servoTimer_t timer)
-{
- // returns true if any servo is active on this timer
- for(uint8_t channel=0; channel < SERVOS_PER_TIMER; channel++) {
- if(SERVO(timer,channel).Pin.isActive == true)
- return true;
- }
- return false;
-}
-
-
-/****************** end of static functions ******************************/
-
-Servo::Servo()
-{
- if( ServoCount < MAX_SERVOS) {
- this->servoIndex = ServoCount++; // assign a servo index to this instance
- servos[this->servoIndex].ticks = DEFAULT_PULSE_WIDTH * TICKS_PER_uS; // store default values
- }
- else
- this->servoIndex = INVALID_SERVO ; // too many servos
-}
-
-uint8_t Servo::attach(int pin)
-{
- return this->attach(pin, MIN_PULSE_WIDTH, MAX_PULSE_WIDTH);
-}
-
-uint8_t Servo::attach(int pin, int min, int max)
-{
- if(this->servoIndex < MAX_SERVOS ) {
- pinMode( pin, OUTPUT) ; // set servo pin to output
- servos[this->servoIndex].Pin.nbr = pin;
- // todo min/max check: abs(min - MIN_PULSE_WIDTH) /4 < 128
- this->min = (MIN_PULSE_WIDTH - min)/4; //resolution of min/max is 4 uS
- this->max = (MAX_PULSE_WIDTH - max)/4;
- // initialize the timer if it has not already been initialized
- servoTimer_t timer = SERVO_INDEX_TO_TIMER(servoIndex);
- if(isTimerActive(timer) == false)
- initISR(timer);
- servos[this->servoIndex].Pin.isActive = true; // this must be set after the check for isTimerActive
- }
- return this->servoIndex ;
-}
-
-void Servo::detach()
-{
- servos[this->servoIndex].Pin.isActive = false;
-
-#ifdef FREE_TIMERS
- if(isTimerActive(SERVO_INDEX_TO_TIMER(servoIndex)) == false) {
- ;// call to unimplimented function in wiring.c to re-init timer (set timer back to PWM mode) TODO?
- }
-#endif
-}
-
-void Servo::write(int value)
-{
- if(value < MIN_PULSE_WIDTH)
- { // treat values less than 544 as angles in degrees (valid values in microseconds are handled as microseconds)
- if(value < 0) value = 0;
- if(value > 180) value = 180;
- value = map(value, 0, 180, SERVO_MIN(), SERVO_MAX());
- }
- this->writeMicroseconds(value);
-}
-
-void Servo::writeMicroseconds(int value)
-{
- // calculate and store the values for the given channel
- byte channel = this->servoIndex;
- if( (channel >= 0) && (channel < MAX_SERVOS) ) // ensure channel is valid
- {
- if( value < SERVO_MIN() ) // ensure pulse width is valid
- value = SERVO_MIN();
- else if( value > SERVO_MAX() )
- value = SERVO_MAX();
-
- value = (value-TRIM_DURATION) * TICKS_PER_uS; // convert to ticks after compensating for interrupt overhead
- uint8_t oldSREG = SREG;
- cli();
- servos[channel].ticks = value;
- SREG = oldSREG;
- }
-}
-
-int Servo::read() // return the value as degrees
-{
- return map( this->readMicroseconds()+1, SERVO_MIN(), SERVO_MAX(), 0, 180);
-}
-
-int Servo::readMicroseconds()
-{
- unsigned int pulsewidth;
- if( this->servoIndex != INVALID_SERVO )
- pulsewidth = (servos[this->servoIndex].ticks / TICKS_PER_uS) + TRIM_DURATION ;
- else
- pulsewidth = 0;
-
- return pulsewidth;
-}
-
-bool Servo::attached()
-{
- return servos[this->servoIndex].Pin.isActive ;
-}