diff options
Diffstat (limited to 'libraries/Servo')
| -rw-r--r-- | libraries/Servo/Servo.cpp | 337 | ||||
| -rw-r--r-- | libraries/Servo/Servo.h | 126 | ||||
| -rw-r--r-- | libraries/Servo/examples/Knob/Knob.ino | 22 | ||||
| -rw-r--r-- | libraries/Servo/examples/Sweep/Sweep.ino | 31 | ||||
| -rw-r--r-- | libraries/Servo/keywords.txt | 24 | 
5 files changed, 540 insertions, 0 deletions
| diff --git a/libraries/Servo/Servo.cpp b/libraries/Servo/Servo.cpp new file mode 100644 index 0000000..a17ed34 --- /dev/null +++ b/libraries/Servo/Servo.cpp @@ -0,0 +1,337 @@ +/*
 + 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 <avr/interrupt.h>
 +#include <Arduino.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) + 4 < usToTicks(REFRESH_INTERVAL) )  // 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)
 +ISR(TIMER1_COMPA_vect) 
 +{ 
 +  handle_interrupts(_timer1, &TCNT1, &OCR1A); 
 +}
 +#endif
 +
 +#if defined(_useTimer3)
 +ISR(TIMER3_COMPA_vect) 
 +{ 
 +  handle_interrupts(_timer3, &TCNT3, &OCR3A); 
 +}
 +#endif
 +
 +#if defined(_useTimer4)
 +ISR(TIMER4_COMPA_vect) 
 +{
 +  handle_interrupts(_timer4, &TCNT4, &OCR4A); 
 +}
 +#endif
 +
 +#if defined(_useTimer5)
 +ISR(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 < 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 ;
 +}
 diff --git a/libraries/Servo/Servo.h b/libraries/Servo/Servo.h new file mode 100644 index 0000000..8168494 --- /dev/null +++ b/libraries/Servo/Servo.h @@ -0,0 +1,126 @@ +/* +  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 sieze 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.  + */ + +#ifndef Servo_h +#define Servo_h + +#include <inttypes.h> + +/*  + * 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 _useTimer1  +typedef enum { _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 diff --git a/libraries/Servo/examples/Knob/Knob.ino b/libraries/Servo/examples/Knob/Knob.ino new file mode 100644 index 0000000..886e107 --- /dev/null +++ b/libraries/Servo/examples/Knob/Knob.ino @@ -0,0 +1,22 @@ +// Controlling a servo position using a potentiometer (variable resistor)  +// by Michal Rinott <http://people.interaction-ivrea.it/m.rinott>  + +#include <Servo.h>  +  +Servo myservo;  // create servo object to control a servo  +  +int potpin = 0;  // analog pin used to connect the potentiometer +int val;    // variable to read the value from the analog pin  +  +void setup()  +{  +  myservo.attach(9);  // attaches the servo on pin 9 to the servo object  +}  +  +void loop()  +{  +  val = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)  +  val = map(val, 0, 1023, 0, 179);     // scale it to use it with the servo (value between 0 and 180)  +  myservo.write(val);                  // sets the servo position according to the scaled value  +  delay(15);                           // waits for the servo to get there  +}  diff --git a/libraries/Servo/examples/Sweep/Sweep.ino b/libraries/Servo/examples/Sweep/Sweep.ino new file mode 100644 index 0000000..fb326e7 --- /dev/null +++ b/libraries/Servo/examples/Sweep/Sweep.ino @@ -0,0 +1,31 @@ +// Sweep +// by BARRAGAN <http://barraganstudio.com>  +// This example code is in the public domain. + + +#include <Servo.h>  +  +Servo myservo;  // create servo object to control a servo  +                // a maximum of eight servo objects can be created  +  +int pos = 0;    // variable to store the servo position  +  +void setup()  +{  +  myservo.attach(9);  // attaches the servo on pin 9 to the servo object  +}  +  +  +void loop()  +{  +  for(pos = 0; pos < 180; pos += 1)  // goes from 0 degrees to 180 degrees  +  {                                  // in steps of 1 degree  +    myservo.write(pos);              // tell servo to go to position in variable 'pos'  +    delay(15);                       // waits 15ms for the servo to reach the position  +  }  +  for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees  +  {                                 +    myservo.write(pos);              // tell servo to go to position in variable 'pos'  +    delay(15);                       // waits 15ms for the servo to reach the position  +  }  +}  diff --git a/libraries/Servo/keywords.txt b/libraries/Servo/keywords.txt new file mode 100644 index 0000000..ca5ba79 --- /dev/null +++ b/libraries/Servo/keywords.txt @@ -0,0 +1,24 @@ +####################################### +# Syntax Coloring Map Servo +####################################### + +####################################### +# Datatypes (KEYWORD1) +####################################### + +Servo	KEYWORD1 + +####################################### +# Methods and Functions (KEYWORD2) +####################################### +attach	KEYWORD2 +detach	KEYWORD2 +write	KEYWORD2 +read	KEYWORD2 +attached	KEYWORD2 +writeMicroseconds	KEYWORD2 +readMicroseconds	KEYWORD2 + +####################################### +# Constants (LITERAL1) +####################################### | 
