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[Reply #15 on:]

Continued below;

Code:

/*
 Servo.cpp - Interrupt driven Servo library for Arduino using 16 bit timers- Version 2
 Copyright (c) 2009 Michael Margolis.  All right reserved.
 */
/*
 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 <avr/interrupt.h>
#include <WProgram.h>

#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

[Reply #16 on:]

The rest, servo.cpp alone is still more than 9500 characters

Code:

#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 ;
}

PaulS - you're help is greatly appreciated, genuinely.

[Reply #17 on:]

My version of Servo.cpp, in the 1.0.3 libraries folder contains:

Code:

#include <avr/interrupt.h>
#include <Arduino.h>

#include "Servo.h"

You need to uninstall your version of the IDE and reinstall, to get the correct 1,0+ version of the Servo library.

[Reply #18 on:]

PaulS, you are the man.

Uninstalled and re-installed and it verifies perfectly - It's my birthday today too and this is probably the best present!

Code:

Binary sketch size: 6,088 bytes (of a 32,256 byte maximum)

Thanks again, your time taken to look over all this has been much appreciated, i owe you one!

Now just to get the physical circuit working...

[Reply #19 on:]

Now just to get the physical circuit working...

On the subject of which, are the components you plan to use, eg the Arduino and the servo, safe for use (either intrinsically or by flash-proofing) in hazardous areas? Or will they be outside the hazardous area?

[Reply #20 on:]

Now just to get the physical circuit working...

On the subject of which, are the components you plan to use, eg the Arduino and the servo, safe for use (either intrinsically or by flash-proofing) in hazardous areas? Or will they be outside the hazardous area?

Sorry for the delay.

As per any hazardous area installation, as many of the components and circuitry as possible will be installed in an adjacent safe area.  So the Arduino itself will be outside and a zener barrier will be utilised along with appropriate cable and glands.  Inside will be an oxygen meter and ventilation fan - these won't be in this model though, unless i find the time and motivation (and knowledge) to include them!