3 stepper motors and an audio board trigger

[eanderso13]

Hey everyone. I've poked around a bit on here and seen some references to using a PROP-1 or 2 to drive a stepper motor or two but I wanted to get some advice on my possible application. I've basically got a broken slot machine which someone wants me to rig up as a show piece and have the reels spin, then stop, about 10 times and then every 10th time trigger an audio track of a "jackpot" sound. The stepper motors inside the reels appear to be unipolar (6 wires), possibly hybrid, but they also appear to be older, out of production Japanese motors that I can't find any real data for. (PLU004-1000). So I basically would want the three reels to spin in unison at a relatively quick rate, then all stop. Pause for a few seconds, then start again. Would the Prop-2 have enough outputs for three unipolar steppers plus one output to trigger an audio board? I assume the 16 I/O is enough as I'd just need 12 for the motors from what I can tell. I'd also like to use my PROP-1 to drive a single motor as a proof of concept, before i spend the money on a PROP-2 board and just to make sure the motors all work.

Thanks for any input on this.

-Eric

[JonnyMac]

Two concerns:

1) What kind of current does each coil of the stepper require? The ULN2x03 in the Prop-1/2 may not be able to handle this.
2) Running one stepper is easy, running multiples (at the same time) not so easy.

The current issue will be less a problem if the outputs can float (that is, they don't have to maintain a step position to hold the motor still).

The HC-8+ was created for these kinds of situations. Yes, it only has eight outputs, but they're high current and the multi-core Propeller processor allows complex applications to be coded fairly easily. We are presently working to get the Rev F PCB into production. I just got a test board the day before Christmas and I'm really happy (aside from the small pre-production tweaks we have to make).

[eanderso13]

Thanks, Johnny. Yeah, I'm a bit concerned with the lack of motor documentation. In looking at other slot machine stepper motors, they all seem to run in the 300-400mA range. I know its not my motor specs, but its something to possible go on...

I was looking at the HC8 and wondering if I could use it to run all three motors off of a single set of outputs so that they just all spin and stop at the same time. Or maybe two could be used together? Although if I do that, it starts getting pretty expensive in the parts department, and I just received word yesterday that this guy has a few more dead slot machines he wants me to do the same to...if i can fine a reasonable solution.

Due to the nature of how the PBASIC code executes I was also concerned about getting smooth movement out of 3 motors simultaneously.

Thanks for your input!

[livinlowe]

I can't pull up the full information from Satistronics website, but looks like its a two phase six wires step motor PLU004-1000, with 1000 step increments or .36 degree accuracy. Possibly google another motor with this characteristic ( or get Satistronics website to pull up *Geez!*) to estimate the current draw per phase. It shouldn't be too hard to randomize each line of the slot machine (just hard to make it random enough for the house to win 99.5% of the time lol)