Ultimarc ServoStik with alternative hardware motor controller

[blacketj]

I'm building a 1-player control panel/fight stick that plugs into any computer via USB.  I really wanted to have both 4-way and 8-way functionality, but didn't want to put two sticks on my panel because I didn't want it to get too big or crowded.  So the ServoStik looked like a great option for me.  It is one of the more expensive options, with the stick costing $40 and the motor controller board at $30.

Ultimarc's controller board seemed like a great option for a cabinet builder where the cp would only ever be used with one computer.  But I plan on taking this to a buddy's house or using on different computers in my own house.  So having to set up the software switching on all those computers seems like it would be a pain.  So I want to just do the switching via a couple buttons on my cp.  Ultimarc's controller board allows this option, which they call 'hardware mode', but once you put the board in hardware mode you can never undo it.  That seemed like a waste of money to buy the board and then permanently disable one of its features.  I figured there must be a cheaper solution.

A quick search on ebay and I found lots of motor controller boards.  Most based on a variation of the L298 integrated circuit.  This seems to be a very popular IC for such an application.  And these boards ranged from about $6-10 including shipping, quite a bit cheaper than Ultimarc's.   I ordered one that was $7. 

It arrived yesterday so I set up a test circuit to see if it would work how I wanted it to.  All of it is powered off of my IPac2, and it worked great.  I have it set up with two buttons.  One to put it into 4-way and another to put it into 8-way.  So I just wanted to share this in case anyone else was thinking of doing a similar control panel setup.

Here is a video I posted of my test setup.

[AndyWarne]

The question is though, how are you turning off the motor when it reaches the end of its travel? If the controller does not do this, and you press the button for longer than necessary it will burn out the motor.

Note our board controls 2 joysticks.

[jasonbar]

Andy, does the ServoStik controller turn off the motors after a set amount of time, or does it have current limiting that detects stall & turns them off?

I'm assuming that there's no encoder position feedback, since the ServoStik uses PMDC brush motors that have but 2 wires leaving the motor/gearbox/horn assembly.

Thanks,
-Jason