ShowInfo

This sketch shows information about the Arduino itself. It is mostly technical internal information.

The serial monitor should to be opened to see the information. A menu is presented with a few options:

Arduino ShowInfo
Show what the Arduino has to tell you.

Menu
-----------
0 = System LED off
1 = System LED on
2 = i2c_scanner
i = Show information
h = Show menu
r = Test serial communication
s = Speed tests
t = Timer Register Dump
? = Show menu

Type command, followed by Enter

The sketch below can be used to test the Arduino, without any extra hardware connected to it.
It is tested on a Arduino Uno, Leonardo and Mega 2560 .


Speed tests

This is the result of the speed test with the sketch (version December 2014) using Arduino 1.5.8 BETA with Arduino Uno. It shows clearly the problem with the software implementation of the division. Both the integer and floating point division is a lot slower than multiplying.

Note that with other versions of the Arduino and with other boards, some results are slower and some are faster.

Speed test
----------
F_CPU = 16000000 Hz
1/F_CPU = 0.0625 us
The next tests are runtime compensated for overhead
Interrupts are still enabled, because millis() is used for timing
  nop                       : 0.063 us
  avr gcc I/O               : 0.125 us
  Arduino digitalRead       : 3.585 us
  Arduino digitalWrite      : 5.092 us
  pinMode                   : 4.217 us
  multiply byte             : 0.632 us
  divide byte               : 5.412 us
  add byte                  : 0.569 us
  multiply integer          : 1.387 us
  divide integer            : 14.277 us
  add integer               : 0.883 us
  multiply long             : 6.100 us
  divide long               : 38.687 us
  add long                  : 1.763 us
  multiply float            : 7.110 us
  divide float              : 79.962 us
  add float                 : 9.227 us
  itoa()                    : 13.397 us
  ltoa()                    : 126.487 us
  dtostrf()                 : 78.962 us
  random()                  : 51.512 us
  y |= (1<<x)               : 0.569 us
  bitSet()                  : 0.569 us
  analogRead()              : 111.987 us
  analogWrite() PWM         : 11.732 us
  delay(1)                  : 1006.987 us
  delay(100)                : 99999.984 us
  delayMicroseconds(2)      : 0.506 us
  delayMicroseconds(5)      : 3.587 us
  delayMicroseconds(100)    : 99.087 us
-----------


More

Read about the Internal Temperature Sensor.

If you want more testing, see the "Arduino Explorer" : http://www.avr-developers.com/arduino_exp.html (not compatible with the current version of the Arduino IDE)

An generic protocol to control the inputs and outputs of the Arduino by a program on a computer is called "Firmata" : http://playground.arduino.cc/Interfacing/Firmata


Code

// -----------------------------------------------------
// Arduino ShowInfo
// Show what the Arduino has to tell you.
//
// 10 April 2012: Extra speed tests,
//                and a few other additions.
// 17 April 2012: The name 'ADCW' is preferred over 'ADC'.
// 23 April 2012: Changed PB5 into PORTB5.
// 1 July 2012  : Added i2c_scanner.
//                More speed tests.
// 21 July 2012 : Added divide speed tests.
// 25 July 2012 : Added sketchSize.
// 26 July 2012 : Changed sketchSize for more than 64kB.
//                Also show sketchSize in percentage.
//                Added processor defines.
//                Arduino Mega compatible (not tested).
// 5 November 2014 : Tested on Arduino Mega 2560
//                Added Arduino version "ARDUINO".
//                Replaced "double" with "float".
//                The i2c scanner scans now 1 up to 126,
//                  it was 0 up to 127.
//                Added UTF-8 test.
//                The delayMicroseconds(1) replaced by
//                  2 micro seconds. I think one micro second
//                  was not called.
//                The analogReference() timing removed,
//                  I think it was not called.
// 4 December 2014 : Delay to allow the Serial.print to be printed.
//                More floating point and 32-bit integer tests.
//                Tested with Arduino 1.0.6 and Leonardo and Uno.
// -----------------------------------------------------

#include <avr/boot.h>
#include <Wire.h>

void setup()
{
  // The system led is present on most Arduino boards.
  pinMode(13,OUTPUT);

  Serial.begin(9600);

#if defined (__AVR_ATmega32U4__)
  while(!Serial);        // For Leonardo, wait for serial port
#endif


  Serial.println(F("Arduino ShowInfo"));
  Serial.println(F("Show what the Arduino has to tell you."));

  ShowMenu();
}


void loop()
{
  int incomingByte, i, n;

  if (Serial.available() > 0)
  {
    incomingByte = Serial.read();

    switch (incomingByte)
    {
#if !defined (__AVR_ATmega32U4__)
      case '0':
        Serial.println(F("System LED off"));
        digitalWrite(13,LOW);
        Serial.println(F("-----------"));
        break;
      case '1':
        Serial.println(F("System LED on"));
        digitalWrite(13,HIGH);
        Serial.println(F("-----------"));
        break;
      case '2':
        i2c_scanner();
        break;
#endif
      case 'i':
        Information();
        break;
      case 'r':
        Serial.println(F("Test serial communcation"));
        Serial.println(F("Will your terminal program send characters immediately?"));
        Serial.println(F("Enter characters, followed by Enter"));
        for (i=0; i<25; i++)
        {
          Serial.print(F("Serial.available() = "));
          n = Serial.available();
          Serial.print(n,DEC);
          Serial.print(F("    Serial.peek() = "));
          n = Serial.peek();
          Serial.println(n,DEC);
          delay(500);
        }
        // empty the buffer of incoming data
        while (Serial.available() > 0)
          Serial.read();
        Serial.println(F("-----------"));
        break;
      case 's':
        SpeedTest();
        break;
#if !defined (__AVR_ATmega32U4__)
      case 't':
        TimerRegisterDump();
        break;
#endif
      case 'h':
      case '?':
        ShowMenu();
        break;
      // Ignore some characters, like the carriage return and line feed.
      case '\'':
      case '\r':
      case '\n':
        break;
      default:
        Serial.print(F("Unknown command: 0x"));
        Serial.println(incomingByte,HEX);
        Serial.println(F("Type '?' followed by Enter"));
        // Something could be wrong, delete incoming data in buffer
        while (Serial.available() > 0)
          Serial.read();
        Serial.println(F("-----------"));
        break;        
    }
  }
}



void ShowMenu(void)
{
  Serial.println(F(""));
  Serial.println(F("Menu"));
  Serial.println(F("-----------"));
#if !defined (__AVR_ATmega32U4__)
  Serial.println(F("0 = System LED off"));
  Serial.println(F("1 = System LED on"));
  Serial.println(F("2 = i2c_scanner"));
#endif
  Serial.println(F("i = Show information"));
  Serial.println(F("h = Show menu"));
  Serial.println(F("r = Test serial communication"));
  Serial.println(F("s = Speed tests"));
#if !defined (__AVR_ATmega32U4__)
  Serial.println(F("t = Timer Register Dump"));
#endif
  Serial.println(F("? = Show menu"));
  Serial.println(F(""));
  Serial.println(F("Type command, followed by Enter"));
}



float GetTemp(void)
{
  unsigned int wADC;
  float t;

  // The internal temperature has to be used
  // with the internal reference of 1.1V.
  // Channel 8 can not be selected with
  // the analogRead function yet.

  // This code is not valid for the Arduino Mega,
  // and the Arduino Mega 2560.

#ifdef THIS_MIGHT_BE_VALID_IN_THE_FUTURE
  analogReference (INTERNAL);
  delay(20);            // wait for voltages to become stable.
  wADC = analogRead(8); // Channel 8 is temperature sensor.
#else
  // Set the internal reference and mux.
  ADMUX = (_BV(REFS1) | _BV(REFS0) | _BV(MUX3));
  ADCSRA |= _BV(ADEN);  // enable the ADC

  delay(20);            // wait for voltages to become stable.

  ADCSRA |= _BV(ADSC);  // Start the ADC

  // Detect end-of-conversion
  while (bit_is_set(ADCSRA,ADSC));

  // Reading register "ADCW" takes care of how to read ADCL and ADCH.
#if defined (__AVR_ATmega32U4__)
  wADC = ADC;      // For Arduino Leonardo
#else
  wADC = ADCW;     // 'ADCW' is preferred over 'ADC'
#endif
#endif

  // The offset of 337.0 could be wrong. It is just an indication.
  t = (wADC - 337.0 ) / 1.22;

  return (t);
}



// Helper function for free ram.
//   With use of http://playground.arduino.cc/Code/AvailableMemory
//
int freeRam(void)
{
  extern unsigned int __heap_start;
  extern void *__brkval;

  int free_memory;
  int stack_here;

  if (__brkval == 0)
    free_memory = (int) &stack_here - (int) &__heap_start;
  else
    free_memory = (int) &stack_here - (int) __brkval;

  return (free_memory);
}



// Helper function for sketch size.
// The sketch size is runtime calculated.
// From user "Coding Badly" in his post:
//   http://arduino.cc/forum/index.php/topic,115870.msg872309.html#msg872309
// Changed into unsigned long for code size larger than 64kB.
//
// This function returns the sketch size
// for a size between 0 and 32k. If the code
// size is larger (for example with an Arduino Mega),
// the return value is not valid.
//
unsigned long sketchSize(void)
{
  extern int _etext;
  extern int _edata;

  return ((unsigned long)(&_etext) + ((unsigned long)(&_edata) - 256L));
}



void Information(void)
{
  int i,j;
  int data1,data2,data3,data4;
  unsigned long ul;
  float percentage;

  Serial.println(F(""));
#if !defined (__AVR_ATmega32U4__)
  Serial.println(F("Information"));
  Serial.println(F("-----------"));

  Serial.print(F("sketch Size = "));
  ul = sketchSize();
  Serial.print(ul,DEC);
  Serial.print(F(" ("));
  percentage = (float) ul / ((float) FLASHEND + 1.0) * 100.0;
  Serial.print(percentage,0);
  Serial.println(F("%)"));

  Serial.print(F("free RAM    = "));
  i = freeRam();
  Serial.println(i,DEC);
  Serial.print(F("RAM used    = "));
  j = (RAMEND + 1) - i;
  Serial.print(j, DEC);
  Serial.print(F(" ("));
  percentage = (float) j / ((float) RAMEND + 1.0) * 100.0;
  Serial.print(percentage,0);
  Serial.println(F("%)"));
#endif

  Serial.print(F("ARDUINO = "));
  Serial.print(ARDUINO);
  Serial.print(F(" (Arduino version "));
  Serial.print( (float) ARDUINO / 100.0, 2);
  Serial.println(F(")"));

  Serial.print(F("__VERSION__ = "));
  Serial.println(F(__VERSION__));

  Serial.print(F("__DATE__    = "));
  Serial.println(F(__DATE__));

  Serial.print(F("__TIME__    = "));
  Serial.println(F(__TIME__));

  Serial.print(F("__AVR_LIBC_VERSION_STRING__ = "));
  Serial.println(F(__AVR_LIBC_VERSION_STRING__));

  Serial.print(F("__FILE__    = "));
  Serial.println(F(__FILE__));

  Serial.print(F("__STDC__    = "));
  Serial.println(__STDC__,DEC);

#if !defined (__AVR_ATmega32U4__)
  Serial.print(F("OSCCAL = "));
  Serial.println(OSCCAL,DEC);

  Serial.print(F("GPIOR0 = 0x"));
  Serial.println(GPIOR0,HEX);

  Serial.print(F("GPIOR1 = 0x"));
  Serial.println(GPIOR1,HEX);

  Serial.print(F("GPIOR1 = 0x"));
  Serial.println(GPIOR1,HEX);
#endif

  Serial.print(F("RAMEND   = 0x"));
  Serial.println(RAMEND,HEX);

  Serial.print(F("XRAMEND  = 0x"));
  Serial.println(XRAMEND,HEX);

  Serial.print(F("E2END    = 0x"));
  Serial.println(E2END,HEX);

  Serial.print(F("FLASHEND = 0x"));
  Serial.println(FLASHEND,HEX);

  cli();
  data1 = boot_lock_fuse_bits_get(GET_LOW_FUSE_BITS);
  data2 = boot_lock_fuse_bits_get(GET_HIGH_FUSE_BITS);
  data3 = boot_lock_fuse_bits_get(GET_EXTENDED_FUSE_BITS);
  data4 = boot_lock_fuse_bits_get(GET_LOCK_BITS);
  sei();

  Serial.print(F("LOW FUSE      = 0x"));
  Serial.println(data1,HEX);

  Serial.print(F("HIGH FUSE     = 0x"));
  Serial.println(data2,HEX);

  Serial.print(F("EXTENDED FUSE = 0x"));
  Serial.println(data3,HEX);

  Serial.print(F("LOCK BITS     = 0x"));
  Serial.println(data4,HEX);

  Serial.print(F("Processor according to compiler = "));
#if defined (__AVR_ATtiny45__)
  Serial.println(F("__AVR_ATtiny45__"));
#elif defined (__AVR_ATtiny85__)
  Serial.println(F("__AVR_ATtiny85__"));
#elif defined (__AVR_ATtiny2313__)
  Serial.println(F("__AVR_ATtiny2313__"));
#elif defined (__AVR_ATtiny2313A__)
  Serial.println(F("__AVR_ATtiny2313A__"));
#elif defined (__AVR_ATmega48__)
  Serial.println(F("__AVR_ATmega48__"));
#elif defined (__AVR_ATmega48A__)
  Serial.println(F("__AVR_ATmega48A__"));
#elif defined (__AVR_ATmega48P__)
  Serial.println(F("__AVR_ATmega48P__"));
#elif defined (__AVR_ATmega8__)
  Serial.println(F("__AVR_ATmega8__"));
#elif defined (__AVR_ATmega8U2__)
  Serial.println(F("__AVR_ATmega8U2__"));
#elif defined (__AVR_ATmega88__)
  Serial.println(F("__AVR_ATmega88__"));
#elif defined (__AVR_ATmega88A__)
  Serial.println(F("__AVR_ATmega88A__"));
#elif defined (__AVR_ATmega88P__)
  Serial.println(F("__AVR_ATmega88P__"));
#elif defined (__AVR_ATmega88PA__)
  Serial.println(F("__AVR_ATmega88PA__"));
#elif defined (__AVR_ATmega16__)
  Serial.println(F("__AVR_ATmega16__"));
#elif defined (__AVR_ATmega168__)
  Serial.println(F("__AVR_ATmega168__"));
#elif defined (__AVR_ATmega168A__)
  Serial.println(F("__AVR_ATmega168A__"));
#elif defined (__AVR_ATmega168P__)
  Serial.println(F("__AVR_ATmega168P__"));
#elif defined (__AVR_ATmega32__)
  Serial.println(F("__AVR_ATmega32__"));
#elif defined (__AVR_ATmega328__)
  Serial.println(F("__AVR_ATmega328__"));
#elif defined (__AVR_ATmega328P__)
  Serial.println(F("__AVR_ATmega328P__"));
#elif defined (__AVR_ATmega32U2__)
  Serial.println(F("__AVR_ATmega32U2__"));
#elif defined (__AVR_ATmega32U4__)
  Serial.println(F("__AVR_ATmega32U4__"));
#elif defined (__AVR_ATmega32U6__)
  Serial.println(F("__AVR_ATmega32U6__"));
#elif defined (__AVR_ATmega128__)
  Serial.println(F("__AVR_ATmega128__"));
#elif defined (__AVR_ATmega1280__)
  Serial.println(F("__AVR_ATmega1280__"));
#elif defined (__AVR_ATmega2560__)
  Serial.println(F("__AVR_ATmega2560__"));
#endif

#ifdef SIGRD
  Serial.print(F("SIGRD = "));
  Serial.println(SIGRD,DEC);
#else
  Serial.println(F("SIGRD : not defined (let's make it 5 and see what happens)."));
#define SIGRD 5
#endif

  Serial.print(F("Signature = 0x"));

  data1 = boot_signature_byte_get(0x00);
  data2 = boot_signature_byte_get(0x02);
  data3 = boot_signature_byte_get(0x04);
  data4 = boot_signature_byte_get(0x01);

  Serial.print(data1,HEX);
  Serial.print(F(", 0x"));
  Serial.print(data2,HEX);
  Serial.print(F(", 0x"));
  Serial.println(data3,HEX);

  Serial.print(F("calibration = "));
  Serial.println(data3,DEC);

#if !defined (__AVR_ATmega32U4__)
  Serial.print(F("Number of seconds since start = "));
  Serial.println(millis()/1000L,DEC);
#endif

#if defined (__AVR_ATmega328P__)
  Serial.print(F("Internal Temperature = "));
  Serial.print(GetTemp(),1);
  Serial.println(F(" Celsius   (the offset could be wrong)."));
#endif

  Serial.println(F("UTF-8 test:"));
  Serial.println(F("    Micro µ µ µ µ µ µ µ µ µ µ"));
  Serial.println(F("    Euro  â?¬ â?¬ â?¬ â?¬ â?¬ â?¬ â?¬ â?¬ â?¬ â?¬"));
  Serial.println(F("    (c)   © © © © © © © © © ©"));

  Serial.println(F("-----------"));
}


#if !defined (__AVR_ATmega32U4__)
void TimerRegisterDump(void)
{
  Serial.println(F("Timer Register dump:"));
  Serial.print(F("TIMER0 TCCR0A = 0x")); Serial.println(TCCR0A,HEX);
  Serial.print(F("TIMER0 TCCR0B = 0x")); Serial.println(TCCR0B,HEX);
  Serial.print(F("TIMER0 OCR0A  = 0x")); Serial.println(OCR0A,HEX);
  Serial.print(F("TIMER0 OCR0B  = 0x")); Serial.println(OCR0B,HEX);
  Serial.print(F("TIMER0 TIMSK0 = 0x")); Serial.println(TIMSK0,HEX);
  Serial.print(F("TIMER0 TCNT0  = 0x")); Serial.println(TCNT0,HEX);
  Serial.print(F("TIMER0 TIFR0  = 0x")); Serial.println(TIFR0,HEX);

  Serial.print(F("TIMER1 TCCR1A = 0x")); Serial.println(TCCR1A,HEX);
  Serial.print(F("TIMER1 TCCR1B = 0x")); Serial.println(TCCR1B,HEX);
  Serial.print(F("TIMER1 TCCR1C = 0x")); Serial.println(TCCR1C,HEX);
  Serial.print(F("TIMER1 OCR1A  = 0x")); Serial.println(OCR1A,HEX);
  Serial.print(F("TIMER1 OCR1B  = 0x")); Serial.println(OCR1B,HEX);
  Serial.print(F("TIMER1 TIMSK1 = 0x")); Serial.println(TIMSK1,HEX);
  Serial.print(F("TIMER1 TCNT1  = 0x")); Serial.println(TCNT1,HEX);
  Serial.print(F("TIMER1 ICR1   = 0x")); Serial.println(ICR1,HEX);
  Serial.print(F("TIMER1 TIFR1  = 0x")); Serial.println(TIFR1,HEX);

  Serial.print(F("TIMER2 TCCR2A = 0x")); Serial.println(TCCR2A,HEX);
  Serial.print(F("TIMER2 TCCR2B = 0x")); Serial.println(TCCR2B,HEX);
  Serial.print(F("TIMER2 OCR2A  = 0x")); Serial.println(OCR2A,HEX);
  Serial.print(F("TIMER2 OCR2B  = 0x")); Serial.println(OCR2B,HEX);
  Serial.print(F("TIMER2 TIMSK2 = 0x")); Serial.println(TIMSK2,HEX);
  Serial.print(F("TIMER2 TCNT2  = 0x")); Serial.println(TCNT2,HEX);
  Serial.print(F("TIMER2 TIFR2  = 0x")); Serial.println(TIFR2,HEX);
  Serial.print(F("TIMER2 ASSR   = 0x")); Serial.println(ASSR,HEX);
  Serial.print(F("TIMERn GTCCR  = 0x")); Serial.println(GTCCR,HEX);

  Serial.println(F("-----------"));
}
#endif


#if !defined (__AVR_ATmega32U4__)
void i2c_scanner(void)
{
  byte error, address;
  int nDevices;

  Serial.println(F(""));
  Serial.println(F("i2c_scanner"));
  Serial.println(F("Scanning..."));

  Wire.begin();

  nDevices = 0;
  for(address = 1; address < 127; address++ )
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0)
    {
      Serial.print(F("I2C device found at address 0x"));
      if (address<16)
        Serial.print(F("0"));
      Serial.print(address,HEX);
      Serial.println(F(" !"));

      nDevices++;
    }
    else if (error==4)
    {
      Serial.print(F("Unknow error at address 0x"));
      if (address<16)
        Serial.print(F("0"));
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println(F("No I2C devices found."));
  else
    Serial.println(F("Done."));

  Serial.println(F("-----------"));
}
#endif


void SpeedTest(void)
{
  register int i,j;
  volatile unsigned char c1,c2;
  volatile int v;
  volatile long l1,l2;
  volatile float f1,f2;
  int p,q,r;
  unsigned long m,n;
  float d, overhead;
  char buffer[30];

  Serial.println(F(""));
  Serial.println(F("Speed test"));
  Serial.println(F("----------"));

  Serial.print(F("F_CPU = "));
  Serial.print(F_CPU,DEC);
  Serial.println(F(" Hz"));
  Serial.print(F("1/F_CPU = "));
  Serial.print((1000000.0/(float)F_CPU),4);
  Serial.println(F(" us"));

#if !defined (__AVR_ATmega32U4__)
  Serial.println(F("The next tests are runtime compensated for overhead"));
  Serial.println(F("Interrupts are still enabled, because millis() is used for timing"));
#endif  
  delay(800);    // Allow the Serial text to be transmitted

  Serial.print(F("  nop                       : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<100; i++)
  {
    for (j=0; j<10000; j++)
    {
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
      asm volatile ("nop");
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;           // in micro seconds
  // Calculate overhead with 'nop' instruction per loop in microseconds
  overhead = d - (20.0 * (1000000.0/(float)F_CPU));
  d -= overhead;
  d /= 20.0;             // per instruction
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  avr gcc I/O               : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<50; i++)
  {
    for (j=0; j<10000; j++)
    {
      // Use system led
      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);

      PORTB |= _BV(PORTB5);
      PORTB &= ~_BV(PORTB5);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  Arduino digitalRead       : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<10000; j++)
    {
      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      

      digitalRead(13);      
      digitalRead(13);      
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  Arduino digitalWrite      : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<10000; j++)
    {
      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      

      digitalWrite(13, HIGH);      
      digitalWrite(13, LOW);      
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  pinMode                   : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<10000; j++)
    {
      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      

      pinMode(13, INPUT);      
      pinMode(13, OUTPUT);      
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  multiply byte             : "));
  c1 = 2;
  c2 = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<20; i++)
  {
    for (j=0; j<10000; j++)
    {
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
      c1 *= c2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  divide byte               : "));
  c1 = 253;
  c2 = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<10000; j++)
    {
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
      c1 /= c2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  add byte                  : "));
  c1 = 1;
  c2 = 2;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<20; i++)
  {
    for (j=0; j<10000; j++)
    {
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
      c1 += c2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  multiply integer          : "));
  volatile int x,y;
  x = 2;
  y = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<10; i++)
  {
    for (j=0; j<10000; j++)
    {
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
      x *= y;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  divide integer            : "));
  x = 31415;
  y = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<10000; j++)
    {
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
      x /= y;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  add integer               : "));
  x = 1;
  y = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<10; i++)
  {
    for (j=0; j<10000; j++)
    {
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
      x += y;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  multiply long             : "));
  l1 = 2;
  l2 = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<10000; j++)
    {
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
      l1 *= l2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  divide long               : "));
  l1 = 2000000000L;
  l2 = 3;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<2000; j++)
    {
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
      l1 /= l2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  add long                  : "));
  l1 = 500000000L;
  l2 = 123;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<4; i++)
  {
    for (j=0; j<10000; j++)
    {
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
      l1 += l2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  multiply float            : "));
  f1 = 3.24;
  f2 = 1.25;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<10000; j++)
    {
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
      f1 *= f2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  divide float              : "));
  f1 = 312645.24;
  f2 = 1.21;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<2000; j++)
    {
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
      f1 /= f2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  add float                 : "));
  f1 = 9876.54;
  f2 = 1.23;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<10000; j++)
    {
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
      f1 += f2;
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  itoa()                    : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<10000; j++)
    {
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
      itoa(i,buffer,10);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  long int l = 314159L;
  Serial.print(F("  ltoa()                    : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<500; j++)
    {
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
      ltoa(l,buffer,10);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  dtostrf()                 : "));
  float d3;
  d3 = 3.14159265;
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<1000; j++)
    {
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
      dtostrf (d3, 6, 2, buffer);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  random()                  : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<2; i++)
  {
    for (j=0; j<1000; j++)
    {
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
      r=random();
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  y |= (1<<x)               : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<20; i++)
  {
    for (j=0; j<10000; j++)
    {
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
      v |= _BV(12);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  bitSet()                  : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<20; i++)
  {
    for (j=0; j<10000; j++)
    {
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
      bitSet (v, 12);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));


// #define ENABLE_ANALOGREFERENCE_TIMING
#ifdef ENABLE_ANALOGREFERENCE_TIMING
  Serial.print(F("  analogReference()         : "));
#if defined (__AVR_ATmega1280__) || defined (__AVR_ATmega2560__)
  #define _NOT_DEFAULT_ INTERNAL1V1
#else
  #define _NOT_DEFAULT_ INTERNAL
#endif
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<20; i++)
  {
    for (j=0; j<10000; j++)
    {
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
      analogReference (_NOT_DEFAULT_);
      analogReference (DEFAULT);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));
#endif


  Serial.print(F("  analogRead()              : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<1000; j++)
    {
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
      analogRead (0);
      analogRead (1);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  analogWrite() PWM         : "));
  // Using pin 13 (system led) for output.
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<10000; j++)
    {
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
      analogWrite (13, 100);
      analogWrite (13, 200);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  delay(1)                  : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<100; j++)
    {
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
      delay(1);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  delay(100)                : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<2; j++)
    {
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
      delay(100);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  delayMicroseconds(2)      : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<20; i++)
  {
    for (j=0; j<10000; j++)
    {
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
      delayMicroseconds(2);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  delayMicroseconds(5)      : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<5; i++)
  {
    for (j=0; j<10000; j++)
    {
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
      delayMicroseconds(5);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));



  Serial.print(F("  delayMicroseconds(100)    : "));
  delay(70);     // Allow the Serial text to be transmitted
  m=millis();
  for (i=0; i<1; i++)
  {
    for (j=0; j<1000; j++)
    {
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
      delayMicroseconds(100);
    }
  }
  n=millis();
  d = ((float)n - (float)m) / ((float)i * (float)j);
  d *= 1000.0;
  d -= overhead;
  d /= 20.0;
  Serial.print (d,3);
  Serial.println (F(" us"));


  Serial.println(F("-----------"));
}

Share