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吧库文件放到这里供研究哈 [pre lang='arduino' line='1' file='Servo.h']#ifndef Servo_h #define Servo_h #include /* * Defines for 16 bit timers used with Servo library * * If _useTimerX is defined then TimerX is a 16 bit timer on the curent board * timer16_Sequence_t enumerates the sequence that the timers should be allocated * _Nbr_16timers indicates how many 16 bit timers are available. * */ // Say which 16 bit timers can be used and in what order #if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) #define _useTimer5 #define _useTimer1 #define _useTimer3 #define _useTimer4 typedef enum { _timer5, _timer1, _timer3, _timer4, _Nbr_16timers } timer16_Sequence_t ; #elif defined(__AVR_ATmega32U4__) #define _useTimer3 #define _useTimer1 typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t ; #elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__) #define _useTimer3 #define _useTimer1 typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t ; #elif defined(__AVR_ATmega128__) ||defined(__AVR_ATmega1281__)||defined(__AVR_ATmega2561__) #define _useTimer3 #define _useTimer1 typedef enum { _timer3, _timer1, _Nbr_16timers } timer16_Sequence_t ; #else // everything else #define _useTimer1 typedef enum { _timer1, _Nbr_16timers } timer16_Sequence_t ; #endif #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 #define SERVOS_PER_TIMER 12 // the maximum number of servos controlled by one timer #define MAX_SERVOS (_Nbr_16timers * SERVOS_PER_TIMER) #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 { 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[/code] [pre lang='arduino' line='1' file='Servo.cpp']#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 < (usToTicks(REFRESH_INTERVAL) + 4) ) // 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 >= 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; 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 ; } [/code] |
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