From 86cce025f4c771ee085eea855220ba39147798c3 Mon Sep 17 00:00:00 2001 From: Erik van der Zalm Date: Sat, 18 May 2013 23:12:28 +0200 Subject: [PATCH] Added #ifdef NUM_SERVOS to servo.cpp --- Marlin/Servo.cpp | 676 ++++++++++++++++++++++++----------------------- 1 file changed, 339 insertions(+), 337 deletions(-) diff --git a/Marlin/Servo.cpp b/Marlin/Servo.cpp index 02138b582..1b42ce0b0 100644 --- a/Marlin/Servo.cpp +++ b/Marlin/Servo.cpp @@ -1,337 +1,339 @@ -/* - 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 -#include - -#include "Servo.h" - -#define usToTicks(_us) (( clockCyclesPerMicrosecond()* _us) / 8) // converts microseconds to tick (assumes prescale of 8) // 12 Aug 2009 -#define ticksToUs(_ticks) (( (unsigned)_ticks * 8)/ clockCyclesPerMicrosecond() ) // converts from ticks back to microseconds - - -#define TRIM_DURATION 2 // compensation ticks to trim adjust for digitalWrite delays // 12 August 2009 - -//#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_16timers ]; // counter for the servo being pulsed for each timer (or -1 if refresh interval) - -uint8_t ServoCount = 0; // the total number of attached servos - - -// convenience macros -#define SERVO_INDEX_TO_TIMER(_servo_nbr) ((timer16_Sequence_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(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 == 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) + 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 -#if defined(_useTimer1) -SIGNAL (TIMER1_COMPA_vect) -{ - handle_interrupts(_timer1, &TCNT1, &OCR1A); -} -#endif - -#if defined(_useTimer3) -SIGNAL (TIMER3_COMPA_vect) -{ - handle_interrupts(_timer3, &TCNT3, &OCR3A); -} -#endif - -#if defined(_useTimer4) -SIGNAL (TIMER4_COMPA_vect) -{ - handle_interrupts(_timer4, &TCNT4, &OCR4A); -} -#endif - -#if defined(_useTimer5) -SIGNAL (TIMER5_COMPA_vect) -{ - handle_interrupts(_timer5, &TCNT5, &OCR5A); -} -#endif - -#elif defined WIRING -// Interrupt handlers for Wiring -#if defined(_useTimer1) -void Timer1Service() -{ - handle_interrupts(_timer1, &TCNT1, &OCR1A); -} -#endif -#if defined(_useTimer3) -void Timer3Service() -{ - handle_interrupts(_timer3, &TCNT3, &OCR3A); -} -#endif -#endif - - -static void initISR(timer16_Sequence_t timer) -{ -#if defined (_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__) - TIFR |= _BV(OCF1A); // clear any pending interrupts; - TIMSK |= _BV(OCIE1A) ; // enable the output compare interrupt -#else - // here if not ATmega8 or ATmega128 - TIFR1 |= _BV(OCF1A); // clear any pending interrupts; - TIMSK1 |= _BV(OCIE1A) ; // enable the output compare interrupt -#endif -#if defined(WIRING) - timerAttach(TIMER1OUTCOMPAREA_INT, Timer1Service); -#endif - } -#endif - -#if defined (_useTimer3) - if(timer == _timer3) { - TCCR3A = 0; // normal counting mode - TCCR3B = _BV(CS31); // set prescaler of 8 - TCNT3 = 0; // clear the timer count -#if defined(__AVR_ATmega128__) - TIFR |= _BV(OCF3A); // clear any pending interrupts; - ETIMSK |= _BV(OCIE3A); // enable the output compare interrupt -#else - TIFR3 = _BV(OCF3A); // clear any pending interrupts; - TIMSK3 = _BV(OCIE3A) ; // enable the output compare interrupt -#endif -#if defined(WIRING) - timerAttach(TIMER3OUTCOMPAREA_INT, Timer3Service); // for Wiring platform only -#endif - } -#endif - -#if defined (_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 - -#if defined (_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 -} - -static void finISR(timer16_Sequence_t timer) -{ - //disable use of the given timer -#if defined WIRING // Wiring - if(timer == _timer1) { - #if defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__) - TIMSK1 &= ~_BV(OCIE1A) ; // disable timer 1 output compare interrupt - #else - TIMSK &= ~_BV(OCIE1A) ; // disable timer 1 output compare interrupt - #endif - timerDetach(TIMER1OUTCOMPAREA_INT); - } - else if(timer == _timer3) { - #if defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__) - TIMSK3 &= ~_BV(OCIE3A); // disable the timer3 output compare A interrupt - #else - ETIMSK &= ~_BV(OCIE3A); // disable the timer3 output compare A interrupt - #endif - timerDetach(TIMER3OUTCOMPAREA_INT); - } -#else - //For arduino - in future: call here to a currently undefined function to reset the timer -#endif -} - -static boolean isTimerActive(timer16_Sequence_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 = usToTicks(DEFAULT_PULSE_WIDTH); // store default values - 12 Aug 2009 - } - 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 - timer16_Sequence_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; - timer16_Sequence_t timer = SERVO_INDEX_TO_TIMER(servoIndex); - if(isTimerActive(timer) == false) { - finISR(timer); - } -} - -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 < 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; - value = usToTicks(value); // convert to ticks after compensating for interrupt overhead - 12 Aug 2009 - - 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 = ticksToUs(servos[this->servoIndex].ticks) + TRIM_DURATION ; // 12 aug 2009 - else - pulsewidth = 0; - - return pulsewidth; -} - -bool Servo::attached() -{ - return servos[this->servoIndex].Pin.isActive ; -} +/* + 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. + +*/ +#ifdef NUM_SERVOS +#include +#include + +#include "Servo.h" + +#define usToTicks(_us) (( clockCyclesPerMicrosecond()* _us) / 8) // converts microseconds to tick (assumes prescale of 8) // 12 Aug 2009 +#define ticksToUs(_ticks) (( (unsigned)_ticks * 8)/ clockCyclesPerMicrosecond() ) // converts from ticks back to microseconds + + +#define TRIM_DURATION 2 // compensation ticks to trim adjust for digitalWrite delays // 12 August 2009 + +//#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_16timers ]; // counter for the servo being pulsed for each timer (or -1 if refresh interval) + +uint8_t ServoCount = 0; // the total number of attached servos + + +// convenience macros +#define SERVO_INDEX_TO_TIMER(_servo_nbr) ((timer16_Sequence_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(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 == 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) + 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 +#if defined(_useTimer1) +SIGNAL (TIMER1_COMPA_vect) +{ + handle_interrupts(_timer1, &TCNT1, &OCR1A); +} +#endif + +#if defined(_useTimer3) +SIGNAL (TIMER3_COMPA_vect) +{ + handle_interrupts(_timer3, &TCNT3, &OCR3A); +} +#endif + +#if defined(_useTimer4) +SIGNAL (TIMER4_COMPA_vect) +{ + handle_interrupts(_timer4, &TCNT4, &OCR4A); +} +#endif + +#if defined(_useTimer5) +SIGNAL (TIMER5_COMPA_vect) +{ + handle_interrupts(_timer5, &TCNT5, &OCR5A); +} +#endif + +#elif defined WIRING +// Interrupt handlers for Wiring +#if defined(_useTimer1) +void Timer1Service() +{ + handle_interrupts(_timer1, &TCNT1, &OCR1A); +} +#endif +#if defined(_useTimer3) +void Timer3Service() +{ + handle_interrupts(_timer3, &TCNT3, &OCR3A); +} +#endif +#endif + + +static void initISR(timer16_Sequence_t timer) +{ +#if defined (_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__) + TIFR |= _BV(OCF1A); // clear any pending interrupts; + TIMSK |= _BV(OCIE1A) ; // enable the output compare interrupt +#else + // here if not ATmega8 or ATmega128 + TIFR1 |= _BV(OCF1A); // clear any pending interrupts; + TIMSK1 |= _BV(OCIE1A) ; // enable the output compare interrupt +#endif +#if defined(WIRING) + timerAttach(TIMER1OUTCOMPAREA_INT, Timer1Service); +#endif + } +#endif + +#if defined (_useTimer3) + if(timer == _timer3) { + TCCR3A = 0; // normal counting mode + TCCR3B = _BV(CS31); // set prescaler of 8 + TCNT3 = 0; // clear the timer count +#if defined(__AVR_ATmega128__) + TIFR |= _BV(OCF3A); // clear any pending interrupts; + ETIMSK |= _BV(OCIE3A); // enable the output compare interrupt +#else + TIFR3 = _BV(OCF3A); // clear any pending interrupts; + TIMSK3 = _BV(OCIE3A) ; // enable the output compare interrupt +#endif +#if defined(WIRING) + timerAttach(TIMER3OUTCOMPAREA_INT, Timer3Service); // for Wiring platform only +#endif + } +#endif + +#if defined (_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 + +#if defined (_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 +} + +static void finISR(timer16_Sequence_t timer) +{ + //disable use of the given timer +#if defined WIRING // Wiring + if(timer == _timer1) { + #if defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__) + TIMSK1 &= ~_BV(OCIE1A) ; // disable timer 1 output compare interrupt + #else + TIMSK &= ~_BV(OCIE1A) ; // disable timer 1 output compare interrupt + #endif + timerDetach(TIMER1OUTCOMPAREA_INT); + } + else if(timer == _timer3) { + #if defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__) + TIMSK3 &= ~_BV(OCIE3A); // disable the timer3 output compare A interrupt + #else + ETIMSK &= ~_BV(OCIE3A); // disable the timer3 output compare A interrupt + #endif + timerDetach(TIMER3OUTCOMPAREA_INT); + } +#else + //For arduino - in future: call here to a currently undefined function to reset the timer +#endif +} + +static boolean isTimerActive(timer16_Sequence_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 = usToTicks(DEFAULT_PULSE_WIDTH); // store default values - 12 Aug 2009 + } + 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 + timer16_Sequence_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; + timer16_Sequence_t timer = SERVO_INDEX_TO_TIMER(servoIndex); + if(isTimerActive(timer) == false) { + finISR(timer); + } +} + +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 < 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; + value = usToTicks(value); // convert to ticks after compensating for interrupt overhead - 12 Aug 2009 + + 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 = ticksToUs(servos[this->servoIndex].ticks) + TRIM_DURATION ; // 12 aug 2009 + else + pulsewidth = 0; + + return pulsewidth; +} + +bool Servo::attached() +{ + return servos[this->servoIndex].Pin.isActive ; +} + +#endif