Some new stuff
  1. Arduino Park Control
  2. Arduino USB2serial programming the bare bone
  3. Arduino Projects Videos added
  4. Arduino Xbee projects
  5. Arduino dB Meter 
  6. Trying to get the IOIO going. 
  7. IOIO is going....bluetooth
  8. Attiny 2313 bluetooth bee RC car
  9. Compass and temperature added
  10. AVR programmer
  11. USB2Serial and Ethernet POE
  12. Arduino LPG Sensor
  13. Program the Arduino Mini 05
  14. Lipo Rider Pro in action
  15. EZ Robot Builder kit arrived 10 Nov 2012
  16. Arduino VA Meter!
  17. 05 Nov 2012 Project Sentry Gun.
  18. Attiny85 PIR Sensor 10 Dec 2012 
  19. 0-30VDC3A and 2-28VDC10A bench PSU's
  20. 19 Dec 2012 Arduino Voltmeter LCD
  21. 29 Dec 2012 Arduino Tachometer&Speedometer LCD
  22. 03 Jan 2013 Arduino AC Phase Control. 
  23. 18 Jan 2013 Arduino Distance Meter
  24. 22 Jan 2013 Arduino Digital Clock and Date
  25. 31 Jan 2013 Arduino Digital Clock and Date 8x2 LCD
  26. Feb 2013 LCD and Backpack
  27. Feb 2013 7 Segment Serial Clock Sparkfun. Distance Sensor with "newping" library
  28. Feb 2013 Lelo Remote
  29. 01/03/2013 Arduino Adafruit 7 Seg Digital Clock with RTC and backpack 
  30. Arduino Frequency Meter 26/03/2013
  31. Another RC  Car controlled by Arduino 06/04/2013
  32. My quadcopter project update 25 April 2013
  33. My Aqua Quad Copter Flying 26 April 2013enlightened
  34. Another monster RC truck;strong one! 11July2013cool
  35. X-Frame Quad Copter 31 July 2013cool
  36. Arduino GSM Sheild added.28/8/2013
  37. 1.8inch TFT screen 13/09/2013cool
  38. 04/11/2014 added PID Soldering Iron Control
  39. Added bluetooth servo control 04/11/2014
  40. ESP8266 first try.16/03/2015
  41. Arduino Uno Quadcopter 19 May 2015
  42. IOT WemosD1 Amp Meter

 

 


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29 Dec 2012

Arduino Speedometer on LCD:

Once again I changed the code to make things easier for me while experimenting with the df robot LCD Keypad Shield.

/*

  Example 37.3 � Basic speedometer using millis();

  http://tronixstuff.wordpress.com/tutorials > chapter 37

  John Boxall | CC by-sa-nc  

 To calculate the circumference � use the formula:

circumference = 2πr 

 

where r is the radius of the circle. Now that you have the wheel circumference, this value can be considered as our �fixed distance�,

and therefore the speed can be calculated by measuring the elapsed time between of a full rotation.

Your sensor � once fitted � should act in the same method as a normally-open button that is pushed every rotation. 

Our sketch will measure the time elapsed between every pulse from the sensor. 

To do this, our example will have the sensor output connected to digital pin 2 � as it will trigger an interrupt to calculate the speed. 

*/

#include <LiquidCrystal.h>

LiquidCrystal lcd(8,9,4,5,6,7);

float start, finished;

float elapsed, time;

float circMetric=1.2; // wheel circumference relative to sensor position (in meters)

float circImperial; // using 1 kilometer = 0.621371192 miles

float speedk, speedm;    // holds calculated speed vales in metric and imperial

void setup()

{

  attachInterrupt(0, speedCalc, RISING); // interrupt called when sensors sends digital 2 high (every wheel rotation)

  start=millis();

  // setup LCD

  lcd.begin(16,2);      // initialize the lcd

 // lcd.backlight(); // turn on LCD backlight

  lcd.clear();

  lcd.println(" Wear a helmet! ");

  delay(3000);

  lcd.clear();

  Serial.begin(115200);

  circImperial=circMetric*.62137; // convert metric to imperial for MPH calculations

}

 

void speedCalc()

{

  elapsed=millis()-start;

  start=millis();

  speedk=(3600*circMetric)/elapsed; // km/h

  speedm=(3600*circImperial)/elapsed; // Miles per hour

}

void loop()

{

  lcd.setCursor(0,0);

  lcd.print(int(speedk));

  lcd.print(" km/h ");

  lcd.print(int(speedm));

  lcd.print(" MPH   ");

  lcd.setCursor(0,1);

  lcd.print(int(elapsed));

  lcd.print(" ms/rev      ");

  delay(1000); // adjust for personal preference to minimise flicker

}

 

 

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