From 1359d865c1732c471765177e410817e3e5dbd659 Mon Sep 17 00:00:00 2001 From: "David A. Mellis" Date: Sun, 12 Jul 2009 00:33:02 +0000 Subject: Integrating the new Servo library (MegaServo) by Michael Margolis. Uses timer 1, and, on the Mega, timers 3, 4, and 5 for up to 12 servos (48 on the Mega). --- libraries/Servo/Servo.cpp | 401 +++++++++++++++++++++++++++++-------------- libraries/Servo/Servo.h | 98 +++++++---- libraries/Servo/keywords.txt | 14 +- 3 files changed, 345 insertions(+), 168 deletions(-) (limited to 'libraries/Servo') diff --git a/libraries/Servo/Servo.cpp b/libraries/Servo/Servo.cpp index 8578fef..32cc0e7 100755 --- a/libraries/Servo/Servo.cpp +++ b/libraries/Servo/Servo.cpp @@ -1,133 +1,268 @@ -#include -#include -#include - -/* - Servo.h - Hardware Servo Timer Library - Author: Jim Studt, jim@federated.com - Copyright (c) 2007 David A. Mellis. 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 -*/ - - -uint8_t Servo::attached9 = 0; -uint8_t Servo::attached10 = 0; - -void Servo::seizeTimer1() -{ - uint8_t oldSREG = SREG; - - cli(); - TCCR1A = _BV(WGM11); /* Fast PWM, ICR1 is top */ - TCCR1B = _BV(WGM13) | _BV(WGM12) /* Fast PWM, ICR1 is top */ - | _BV(CS11) /* div 8 clock prescaler */ - ; - OCR1A = 3000; - OCR1B = 3000; - ICR1 = clockCyclesPerMicrosecond()*(20000L/8); // 20000 uS is a bit fast for the refresh, 20ms, but - // it keeps us from overflowing ICR1 at 20MHz clocks - // That "/8" at the end is the prescaler. -#if defined(__AVR_ATmega8__) - TIMSK &= ~(_BV(TICIE1) | _BV(OCIE1A) | _BV(OCIE1B) | _BV(TOIE1) ); -#else - TIMSK1 &= ~(_BV(OCIE1A) | _BV(OCIE1B) | _BV(TOIE1) ); -#endif - - SREG = oldSREG; // undo cli() -} - -void Servo::releaseTimer1() {} - -#define NO_ANGLE (0xff) - -Servo::Servo() : pin(0), angle(NO_ANGLE) {} - -uint8_t Servo::attach(int pinArg) -{ - return attach(pinArg, 544, 2400); -} - -uint8_t Servo::attach(int pinArg, int min, int max) -{ - if (pinArg != 9 && pinArg != 10) return 0; - - min16 = min / 16; - max16 = max / 16; - - pin = pinArg; - angle = NO_ANGLE; - digitalWrite(pin, LOW); - pinMode(pin, OUTPUT); - - if (!attached9 && !attached10) seizeTimer1(); - - if (pin == 9) { - attached9 = 1; - TCCR1A = (TCCR1A & ~_BV(COM1A0)) | _BV(COM1A1); - } - - if (pin == 10) { - attached10 = 1; - TCCR1A = (TCCR1A & ~_BV(COM1B0)) | _BV(COM1B1); - } - return 1; -} - -void Servo::detach() -{ - // muck with timer flags - if (pin == 9) { - attached9 = 0; - TCCR1A = TCCR1A & ~_BV(COM1A0) & ~_BV(COM1A1); - pinMode(pin, INPUT); - } - - if (pin == 10) { - attached10 = 0; - TCCR1A = TCCR1A & ~_BV(COM1B0) & ~_BV(COM1B1); - pinMode(pin, INPUT); - } - - if (!attached9 && !attached10) releaseTimer1(); -} - -void Servo::write(int angleArg) -{ - uint16_t p; - - if (angleArg < 0) angleArg = 0; - if (angleArg > 180) angleArg = 180; - angle = angleArg; - - // bleh, have to use longs to prevent overflow, could be tricky if always a 16MHz clock, but not true - // That 8L on the end is the TCNT1 prescaler, it will need to change if the clock's prescaler changes, - // but then there will likely be an overflow problem, so it will have to be handled by a human. - p = (min16*16L*clockCyclesPerMicrosecond() + (max16-min16)*(16L*clockCyclesPerMicrosecond())*angle/180L)/8L; - if (pin == 9) OCR1A = p; - if (pin == 10) OCR1B = p; -} - -uint8_t Servo::read() -{ - return angle; -} - -uint8_t Servo::attached() -{ - if (pin == 9 && attached9) return 1; - if (pin == 10 && attached10) return 1; - return 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 +#include + + +#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 ; +} diff --git a/libraries/Servo/Servo.h b/libraries/Servo/Servo.h index 0b0e8db..9a25c65 100755 --- a/libraries/Servo/Servo.h +++ b/libraries/Servo/Servo.h @@ -1,10 +1,6 @@ -#ifndef Servo_h -#define Servo_h - /* - Servo.h - Hardware Servo Timer Library - Author: Jim Studt, jim@federated.com - Copyright (c) 2007 David A. Mellis. All right reserved. + Servo.h - 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 @@ -21,32 +17,76 @@ 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 siezed 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. + */ + +#ifndef Servo_h +#define Servo_h + #include +#define Servo_VERSION 2 // software version of this library + +#define MIN_PULSE_WIDTH 544 // the shortest pulse sent to a servo +#define MAX_PULSE_WIDTH 2400 // the longest pulse sent to a servo +#define DEFAULT_PULSE_WIDTH 1500 // default pulse width when servo is attached +#define REFRESH_INTERVAL 20000 // minumim time to refresh servos in microseconds + +#if defined(__AVR_ATmega1280__) +#define MAX_SERVOS 48 // the maximum number of servos (valid range is from 1 to 48) +#else +#define MAX_SERVOS 12 // this library supports up to 12 on a standard Arduino +#endif + +#define INVALID_SERVO 255 // flag indicating an invalid servo index + +typedef struct { + uint8_t nbr :6 ; // a pin number from 0 to 63 + uint8_t isActive :1 ; // true if this channel is enabled, pin not pulsed if false +} ServoPin_t ; + +typedef struct { + ServoPin_t Pin; + unsigned int ticks; +} servo_t; + class Servo { - private: - uint8_t pin; - uint8_t angle; // in degrees - uint8_t min16; // minimum pulse, 16uS units (default is 34) - uint8_t max16; // maximum pulse, 16uS units, 0-4ms range (default is 150) - static void seizeTimer1(); - static void releaseTimer1(); - static uint8_t attached9; - static uint8_t attached10; - public: - Servo(); - uint8_t attach(int); - // pulse length for 0 degrees in microseconds, 544uS default - // pulse length for 180 degrees in microseconds, 2400uS default - uint8_t attach(int, int, int); - // attach to a pin, sets pinMode, returns 0 on failure, won't - // position the servo until a subsequent write() happens - // Only works for 9 and 10. - void detach(); - void write(int); // specify the angle in degrees, 0 to 180 - uint8_t read(); - uint8_t attached(); +public: + Servo(); + uint8_t attach(int pin); // attach the given pin to the next free channel, sets pinMode, returns channel number or 0 if failure + uint8_t attach(int pin, int min, int max); // as above but also sets min and max values for writes. + void detach(); + void write(int value); // if value is < 200 its treated as an angle, otherwise as pulse width in microseconds + void writeMicroseconds(int value); // Write pulse width in microseconds + int read(); // returns current pulse width as an angle between 0 and 180 degrees + int readMicroseconds(); // returns current pulse width in microseconds for this servo (was read_us() in first release) + bool attached(); // return true if this servo is attached, otherwise false +private: + uint8_t servoIndex; // index into the channel data for this servo + int8_t min; // minimum is this value times 4 added to MIN_PULSE_WIDTH + int8_t max; // maximum is this value times 4 added to MAX_PULSE_WIDTH }; -#endif +#endif \ No newline at end of file diff --git a/libraries/Servo/keywords.txt b/libraries/Servo/keywords.txt index 918c46a..ca5ba79 100755 --- a/libraries/Servo/keywords.txt +++ b/libraries/Servo/keywords.txt @@ -6,16 +6,18 @@ # Datatypes (KEYWORD1) ####################################### -Servo KEYWORD1 +Servo KEYWORD1 ####################################### # Methods and Functions (KEYWORD2) ####################################### -attach KEYWORD2 -detach KEYWORD2 -write KEYWORD2 -read KEYWORD2 -attached KEYWORD2 +attach KEYWORD2 +detach KEYWORD2 +write KEYWORD2 +read KEYWORD2 +attached KEYWORD2 +writeMicroseconds KEYWORD2 +readMicroseconds KEYWORD2 ####################################### # Constants (LITERAL1) -- cgit v1.2.3-18-g5258