View Full Version : sweet little trackball (object completed)

Graham Stabler
10-25-2006, 11:09 PM
This thing is so tiny and they have built in LEDs and you push it for a switch function:


I've ordered a few from radio spares (we call it RS but then you will think I mean radio shack) here in the UK, it should take about three seconds to write a mouse object compatible driver. They are not very high res and as such I thought they might be ideal for cursor moving applications in text based programs.

Price in the UK is about 5 pounds, ignore the exchange rate they are probably $5 to you.



Post Edited (Graham Stabler) : 10/30/2006 3:18:06 PM GMT

10-25-2006, 11:45 PM
For the lurkers out there, here is a US source. Sparkfun.com. Lot's of cool stuff.

The same trackball as far as I can figure. They also have a breakout board for the connector. $5.95 for the trackball.


Not affiliated, just a happy customer.


El Paisa
10-26-2006, 01:12 AM

Spark Fun is selling a track ball,

Track Ball with Select, SKU#:·Comp-Track· for about US$5.95.

Cliff L. Biffle
10-26-2006, 01:49 AM
Sweet. The decoder sounds pretty straightforward, too. Doesn't even require phase decoding!

I hope you'll post your work! http://forums.parallax.com/images/smilies/smile.gif

Graham Stabler
10-26-2006, 02:26 AM
Thanks for the link Seth.

I will indeed post my code, shouldn't be much too it at all, its just switches.


Graham Stabler
10-26-2006, 02:36 AM
Oh and I think I can manage an alternative breakout that will cost nothing and be breadboard compatible, as long as that is not mylar flex.


Cliff L. Biffle
10-26-2006, 02:40 AM
It certainly looks like mylar flex. Good luck with that.

Graham Stabler
10-26-2006, 02:45 AM
Hoping its polyimide, I can hope.


Graham Stabler
10-27-2006, 05:52 PM
It turned up this morning and it sure is small. I've made up my little adapter for it and although it was possible the pitch on the flex is very fine so soldering fine wires to it was a bit of a pain.

Firstly the description of the sparkfun site is wrong. The first thing I have done is connect one axis to a couple of LEDs, its a sort of quadrature output, in one direction X makes then X' does (both then on) and in the other direction X' makes first then X does. They both seem to turn off at the same time so I don't think there is a chance to quadruple the resolution and it wouldn't make much sense anyway as it clicks as you roll it and detents lightly.

Suddenly the diagram for the pin-outs makes sense, you have to imagine the switch part on scan position spinning around, it has two stalks, one makes with one X one with X', the direction dictates the switching order.

My unit hasn't got LEDs but not to worry.


Phil Pilgrim (PhiPi)
10-27-2006, 10:01 PM

I didn't see any mounting holes in the datasheet. How do you hold it in place?


Graham Stabler
10-29-2006, 05:03 AM
Phil, Its for consumer goods like phones, they would have clips in the injection mouldings. I'll make do with a hole the same size of the metal ring and some hot glue!

Of if I was feeling professional some sort of clamp between two standoffs.


Graham Stabler
10-30-2006, 10:16 PM
See attached as promised.

Seems to work OK, use is much as the mouse except for different start function.

Allows the use of up to two buttons defined on arbitrary pins so you can use the integral one or an external one or one of each or no buttons.

Demo runs on the TV output, nothing fancy.

I've fully commented it, it covers quite a few assembly topics so may be of general interest.



Graham Stabler
10-31-2006, 05:22 AM
Not very exciting but here's a little video of it in action,

www.youtube.com/watch?v=A62UnJbSezE (http://www.youtube.com/watch?v=A62UnJbSezE)

11-28-2006, 06:37 AM

Just been going through old threads looking for interesting stuff and there is lots.

Minitrack ball as model plane controller?
The prop can generate RF frequencies, could make interesting RC controller.
27MHz, 49MHz etc
A little lcd and you have a programmable RC transmitter.
With 50ma per pin it maybe enough power for indoor RC.
Hook a mosfet up and a bunch of IR leds for IR remote controller.


Graham Stabler
11-28-2006, 08:23 AM
It would be horrible to fly with them. Better to use the sticks out of a PS controller as some have done analogue as things should be.

BUT a good idea overall a tiny computer TX would be fantastic.


p.s. may help in your quest for interesting threads: http://forums.parallax.com/showthread.php?p=609066

11-28-2006, 10:22 AM
Wow thanks Graham, you just saved me hours going through the forums.

I must be doing search wrong, there is stuff I have seen and the only way to find it quick is to click on every page and read every thread. This thread explains a few things.

I should dig out my memsics and make a tilt joystick RF transmitter.