| /* | |
| 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 | |
| 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 sequence used to seize timers is defined in timers.h | |
| 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. | |
| */ | |
| /* | |
| * Defines for 16 bit timers used with Servo library | |
| * | |
| * If _useTimerX is defined then TimerX is a 16 bit timer on the current board | |
| * timer16_Sequence_t enumerates the sequence that the timers should be allocated | |
| * _Nbr_16timers indicates how many 16 bit timers are available. | |
| */ | |
| // Architecture specific include | |
| 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; | |
| volatile unsigned int ticks; | |
| } servo_t; | |
| class Servo | |
| { | |
| 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 | |
| }; | |