I build this speedometer for my own motorcycle. I am using it on my own Honda CD70 motorcycle (70CC) and it is working pretty well. The concept of this speedometer is very simple. A reed switch is used to measure the RPM of the wheel, and some mathematics is used to determine the circumference of the wheel. And that is then used to find the distance traveled in unit time, which is called speed.
In this project only three digital I/O pins of Arduino are used by the Display. And all other pins are available for future addition of functions, like engine temperature, fuel gauge etc.
(1x) 128 x 64 Graphics LCD with blue or yellow background (your choice). Amazon.com
(1x) 40 x 60 mm prototype board Amazon.com
(1x) 220 Ohm 1/4 Watt Resistor Amazon.com
(2x) 10K Ohm 1/4 Watt Resistor Amaz on.com
(1x) 20 Pin single row Male Headers Amazon.com
(1x) 20 Pin single row Female Headers Amazon.com
(1x) 1N4001 Diod (this quantity can increase up to 5 depending on your required functionality). Amazon.com
(1x) Magnetic Reed Switch Amazon.com
(1x) Hall effect Sensor Module (3pins) if you ant to use it instead of reed switch.
If you want to use an Arduino UNO, then the following Items will not be needed.
(1x) Atmega 328p Microcontroller (Arduino UNO Boot loaded).
(1x) 28 pin DIP IC socket Adopter
(1x) 16 MHz Quartz Oscillator
(2x) 22pF Low Voltage DIP Ceramic Disc Capacitors, 50V
(1X) 7805 Voltage Regulator IC.
(2x) 10uF 25V Electrolytic Capacitors.
Double Sided tape.
Soldering Station, or Soldering Iron or Soldering Gun.
An Arduino UNO will be required only for the first time when you burn the code into the Atmega 328p microcontroller.
I am using it with my Motor Cycle, which has its own 12V Battery, so I am using the same battery as supply voltage, If you want to use it with your bike which do not have its own power source, then you should use a 9V Alkaline battery.