Picture of Wireless Altoids Cycle Computer
Front Two.JPG
This instructable will show you the how to build your own remote cycle computer for your bike!
A word of warning though... this one's a monster!!

So a few weeks ago, my usual speedometer for my bike gave up and eventually stopped working completely. I have had it for a good number of years now and it has served me well, but it was obviously time for a replacement. This got me thinking and inspired me to create this Arduino based project. A while ago, I published an instructable documenting how to build a 'Wireless Altoids Display'. It consisted of an 16x2 LCD controlled by an Arduino and a pair of maxsteam Xbee modules. Simple enough, ASCII text sent over serial from the computer would be displayed on the remote LCD. Through this project, I will hopefully be able to show you how you can integrate that setup in a useful application.

What does it do exactly?
The 16x2 display is mounted on the bike's handle bars and provides the user with feedback in terms of how fast they are currently traveling. There is also a nice little bar graph on the top row to provide a visual representation. As well as being able to view your speed in realtime on the bike, the data is also sent wirelessly 'back to base' where the results can be logged and visualised on an moving graph using 'Processing'. The arduino sends the current Speed, Average and Distance covered whilst riding.

Components & Configuration
>> On the bike: (Arduino + Magnetic Reed Switch + Xbee Pro Module + 16x2 LCD)
>> At home: (Xbee Pro Module + FTDI USB Cable)

Let's get to it!
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marios85431 year ago
Where did you find your reed switch??
Looks like an old cycle computer one. Just buy a cheapy one off ebay and use that.
nyo tom1 year ago
What type of magnet should I use? Should I use Neodymium?
Just buy a cycle magnet off ebay for a couple of quid.
bit of tip to help with better connection for the signal is to use a rubber fan grommet on the SP connectors to prevent a connection to the metal case
kashf1 year ago
I love this
13, 7:45 PM.jpg
fooons2 years ago
Hi Alexdlp,
First of all very good job. I want to use your magnific work on my bycicle, but at the moment links are not working and give me a 440 server error. I would like to test it and if I can do some mods for a bigger screen. Could you put links back please.
Thanks and best regards
you should add a simple project box like this

mark out the LCD then get a dremel and cut the box, it will look much better and would be less affected by water

What is the range of the xbee with and without the antenna?
haizul263 years ago
hello, is this the correct type (Arduino ATMega 328) ? :

one more thing,is it possible of i left out part where the antenna has to be installed?is it necessary to have antenna?

thank you. :)
Alexdlp (author)  haizul263 years ago
Yes, the Uno R3 is the latest equivalent board to the old Duemilanove. If you have Xbee's designed for use with an external antenna (for extended signal range), it is very important that you only power the modules with the antenna fitted. Otherwise you risk damaging the board. Hope this helps answer your question :)
tlynch13 years ago
This with another color display would be so awesome to work out for a motorcycle
yaly3 years ago
hi i need only to make the cycle computer without the wireless thingy can you upload a sketch for me with that please and if applicable the use of nokia 3310 lcd which is available to me at the moment instead of the 16x2 charecter lcd thank you
jrhinoferos3 years ago

Great job.

I can't seem to link to the sketch, I am trying a similar project and am a bit lost...

Simpson213 years ago
Looks very well made. I would love to try this out but it looks as if your link to the arduino code has 404'd. Hope to see it back up soon.
Alexdlp (author)  Simpson213 years ago
Should be alright now hopefully, thanks for letting me know :)
francisroan3 years ago
can i use an ir led????with receiver as the reed switch????
Alexdlp (author)  francisroan3 years ago
Do you mean use an IR beam to trigger one cycle of the wheel instead of the magnetic reed switch? Yes, of course but you'll have to modify and tailor the code for your specific application and hardware. It might not be suitable to just plug your IR receiver output into the pins that we are for the reed switch in this project. Hope this helps :)
jimsims3 years ago
Alex, This is , a great project. I am modifying it to display speed, distance, and time ridden on the LCD without XBee. One question is: why use analog input to sense reed switch instead of a digital input? thanks
Alexdlp (author)  jimsims3 years ago
Hey, pleased that you liked it! It would perhaps make more sense to use a digital input - it's just I had difficulty getting the pin to register a HIGH value for some reason. Although I couldn't actually get to see inside the sensor casing, i'm pretty sure it's just a reed switch so.. yeah try and use a digital input :)
jimsims Alexdlp3 years ago
Alex and fjohn, I am using a burglar alarm type magnetic reed switch that is NO (normally open). FYI most burglar alarm switches are NC. I lashed it to the bike with "zip ties". Also, I am using arduino mini-pro so I can fit it all in the altoids tin. I am wired up with 5V to the switch, the mini pro has no 3V pin. I am guessing that there is a resistor in series inside of your reed switch. Can you measure and post the ohms value of your switch with magnet near and far away from switch? Since I am already hard wired with solder to the analog input I would like like to continue with the analog input by adding a resistor. I fried a mini pro with my switch hooked to 5V without a resistor. Thanks.
Alexdlp (author)  jimsims3 years ago
I think a 10K ohm resistor to ground should protect your arduino sufficiently. (Pull down resistor configuration). Hope this works out okay.
francisroan3 years ago
hey can any other sensor be used instead of the reed switch??????
francisroan3 years ago
wen i compiled the stuff the ide showed a few errors like lcd bargraph lbg(&lcd......
Alexdlp (author)  francisroan3 years ago
Make sure you have all of the libraries installed - it's not enough just to run the code. The error that you have is likely to be because you don't have the lcd bar graph library installed correctly. Apologies in advance if this is not the case but I have checked the code and it runs fine every time for me. :)
francisroan3 years ago
could ya check the code again there are a lot of errors wen i compiled it!!!
francisroan3 years ago
could u give the full code????
Alexdlp (author)  francisroan3 years ago
The full code is already listed and can be downloaded from Step 13, the 'Resources' page :)
johnpoole3 years ago
clean build, great documentation.. another for the to do list for my wheel chair, because that's just how i roll..
Jedrokivich3 years ago
I think this is the nicest thing I could ever do for my Trek 820.
I'VE got the same bike. :)
I keep hoping someone will make an LED display bike light/turn signal/message board. Most of the time it'd function as a flashing light for visibility. Flip your front turn signals and it shows what direction you're turning. You could also have pre-programmed messages "Thanks!" "Slow down!" "Move over!" or such. Unfortunately I don't have the electronic knowledge to do so myself.
Nate Ocean3 years ago
Schematic diagram? Block diagram? Anything?
Alexdlp (author)  Nate Ocean3 years ago
I've uploaded a wiring diagram to Step 13 Resources.
You can see the original, full size image here...

Hope this is okay? :)
You ever take it off any sweet jumps?
... we both know I'm training to become a cage fighter.
bill20093 years ago
great instructions.

How does the unprotected display stand up to the elements?
Alexdlp (author)  bill20093 years ago
Thanks, well I've only used it in good weather as it's not waterproof yet. Perhaps that's an improvement to make in the future!
Could this be altered to work with an exercise bike?
Alexdlp (author)  diskincluded3 years ago
Check out the original processing code on this website which has extra features specifically designed for use with a stationary exercise bike...
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