Arduino Skateboard Speedometer

Using an Arduino, it is easy to make a speedometer/tachometer for virtually any man-powered vehicle. I made one for my skateboard that used a small magnet to count revolutions and utilized an LCD display screen.  This Instructable will show you how you can do the same step by step. 

You will need a few things before we get started. 

1) A man-powered vehicle (I will be using a skateboard)
2) An Arduino
3) A plastic Arduino protective box (pictured)
4) A small magnet (mine is 1/4 inch in diameter and about 0.2 inches tall)
5) A magnetic relay switch
6) A 9V battery and an adapter that connects this battery to the Arduino plug (pictured above plugged into an Arduino)
7) A small LCD screen (16 x 2 character display)
8) 10K and 47 Ohm resistors
9) Wires
10) A soldering iron and solder
11) Gorilla glue, super glue, crazy glue, or some adhesive of the sort
12) 10K Potentiometer

Step 1: Putting the Magnet on the Wheel

The first thing I did was embed the small magnet in my rubber skateboard wheel. I drilled a small hole (1/4" diameter to fit the magnet snugly) on the inside of one of my back wheels toward the edge of the wheel. I then dropped some gorilla glue in this hole and fit the magnet in it so about half of the magnet's height was imbedded in the wheel and half was sticking out of the wheel. Later this magnet will allow the magnetic relay switch to count the wheel's revolutions when the relay switch is near the spinning magnet.  

Comments

[Risso]

link for skateboard speedometer code.doc is down ... please re-up

[Ronni530]

Hello I wanted to download the word file containing the code for this project. The link is not working. Can you please fix it. Thank you.

[Richard.s]

I am unable to access the code file shown here.

Can you provide an alternate source to obtain a copy?

Richard

[panchavanparivendhan]

hey urs was the easiest and the cheapest speedometer...and can u mail me the picture of the magnet and the relay attached to the wheel so that i can attach it to my cycle compared to it ........please mail it to me as fast as u can..u can mail me at [e-mail] or [e-mail] or [e-mail].......please reply to me as fast as u can.please please PLEASEE


Thank you!

[TheRealDutchOwner]

Please, for your own sake, do NOT post your email address in public comments! It will attract spammers. Instead, send a personal message to the creator of the instructable.

[painfulfart]

how do you test for sens value and milisegundos value? thanks.. also could someone explain why use a analog input not a digital input since its counting on (1023) and off(0) values?

[bbsux]

Hall effect sensors always "seem" to be better until you look at all the supporting hardware you'll need to setup to make sure they get a clean digital signal. Trust me its not as easy as it sounds.

[idoha]

I think you mean Arduino LONGBOARD Speedometer. Anywho, this is an awesome project, and I love skate/longboard mods. I did notice though, that the box is kinda bulky, and seeing you're only using 1input and 6 outputs, maybe switch out that uno for a pro mini:
http://www.sparkfun.com/products/9218

Not as easy to code, but I think worth it for your project.

[nerd7473]

where did you get the plastic case for the arduino?

[leonardor]

You can find them right here...
http://www.amazon.com/Arduino-Box-for/dp/B003ZKJNVY/ref=sr_1_1?ie=UTF8&qid=1336795573&sr=8-1

[blinkyblinky]

I agree with Technochicken. A few thousand clicks and it is done for. Plus, it would probably miss a few clicks at high speeds...

However, a reed switch will give you easier coding.

Very cool.

[ben_k]

Good project. Rater than using a mechanical relay (was it a reed switch?), it might be more reliable and longer lasting to use a solid state Hall Effect sensor, which does not rely on moving mechanical contacts to sense the magnetic field.