root / arduino-1.0 / libraries / Servo / Servo.h @ 58d82c77
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/*
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Servo.h - Interrupt driven Servo library for Arduino using 16 bit timers- Version 2
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Copyright (c) 2009 Michael Margolis. All right reserved.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/*
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A servo is activated by creating an instance of the Servo class passing the desired pin to the attach() method.
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The servos are pulsed in the background using the value most recently written using the write() method
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Note that analogWrite of PWM on pins associated with the timer are disabled when the first servo is attached.
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Timers are seized as needed in groups of 12 servos - 24 servos use two timers, 48 servos will use four.
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The sequence used to sieze timers is defined in timers.h
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The methods are:
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Servo - Class for manipulating servo motors connected to Arduino pins.
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attach(pin ) - Attaches a servo motor to an i/o pin.
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attach(pin, min, max ) - Attaches to a pin setting min and max values in microseconds
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default min is 544, max is 2400
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write() - Sets the servo angle in degrees. (invalid angle that is valid as pulse in microseconds is treated as microseconds)
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writeMicroseconds() - Sets the servo pulse width in microseconds
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read() - Gets the last written servo pulse width as an angle between 0 and 180.
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readMicroseconds() - Gets the last written servo pulse width in microseconds. (was read_us() in first release)
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attached() - Returns true if there is a servo attached.
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detach() - Stops an attached servos from pulsing its i/o pin.
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*/
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#ifndef Servo_h
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#define Servo_h
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#include <inttypes.h> |
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/*
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* Defines for 16 bit timers used with Servo library
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*
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* If _useTimerX is defined then TimerX is a 16 bit timer on the curent board
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* timer16_Sequence_t enumerates the sequence that the timers should be allocated
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* _Nbr_16timers indicates how many 16 bit timers are available.
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*
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*/
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// Say which 16 bit timers can be used and in what order
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#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
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#define _useTimer5
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#define _useTimer1
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#define _useTimer3
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#define _useTimer4
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typedef enum { _timer5, _timer1, _timer3, _timer4, _Nbr_16timers } timer16_Sequence_t ; |
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#elif defined(__AVR_ATmega32U4__)
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#define _useTimer3
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#define _useTimer1
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typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t ; |
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#elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
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#define _useTimer3
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#define _useTimer1
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typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t ; |
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#elif defined(__AVR_ATmega128__) ||defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__)
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#define _useTimer3
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#define _useTimer1
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typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t ; |
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#else // everything else |
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#define _useTimer1
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typedef enum { _timer1, _Nbr_16timers } timer16_Sequence_t ; |
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#endif
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#define Servo_VERSION 2 // software version of this library |
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#define MIN_PULSE_WIDTH 544 // the shortest pulse sent to a servo |
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#define MAX_PULSE_WIDTH 2400 // the longest pulse sent to a servo |
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#define DEFAULT_PULSE_WIDTH 1500 // default pulse width when servo is attached |
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#define REFRESH_INTERVAL 20000 // minumim time to refresh servos in microseconds |
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#define SERVOS_PER_TIMER 12 // the maximum number of servos controlled by one timer |
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#define MAX_SERVOS (_Nbr_16timers * SERVOS_PER_TIMER)
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#define INVALID_SERVO 255 // flag indicating an invalid servo index |
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typedef struct { |
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uint8_t nbr :6 ; // a pin number from 0 to 63 |
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uint8_t isActive :1 ; // true if this channel is enabled, pin not pulsed if false |
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} ServoPin_t ; |
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typedef struct { |
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ServoPin_t Pin; |
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unsigned int ticks; |
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} servo_t; |
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class Servo |
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{ |
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public:
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Servo(); |
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uint8_t attach(int pin); // attach the given pin to the next free channel, sets pinMode, returns channel number or 0 if failure |
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uint8_t attach(int pin, int min, int max); // as above but also sets min and max values for writes. |
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void detach();
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void write(int value); // if value is < 200 its treated as an angle, otherwise as pulse width in microseconds |
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void writeMicroseconds(int value); // Write pulse width in microseconds |
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int read(); // returns current pulse width as an angle between 0 and 180 degrees |
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int readMicroseconds(); // returns current pulse width in microseconds for this servo (was read_us() in first release) |
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bool attached(); // return true if this servo is attached, otherwise false |
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private:
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uint8_t servoIndex; // index into the channel data for this servo
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int8_t min; // minimum is this value times 4 added to MIN_PULSE_WIDTH
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int8_t max; // maximum is this value times 4 added to MAX_PULSE_WIDTH
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}; |
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#endif
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