Help with LPT Stepper Interface

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06-08-2005, 12:21 AM
nickleplated

Help with LPT Stepper Interface

Picture of the Board

I've been provided this LPT interface to use to control 3 gecko 201's.

I haven't been able to find any documentation for it, and all I was provided with is this pinout list, which itself is a bit confusing to me:

Code:

Max NC Wiring Diagram Pin# Software Req. LPT Interface 1 M3 OUTPUT X_AXIS ENABLE 2 X STEP X_AXIS STEP 3 X DIRECTION Y_AXIS STEP 4 Y STEP Z_AXIS STEP 5 Y DIRECTION A_AXIS STEP 6 Z STEP X_AXIS DIRECTION 7 Z DIRECTION Y_AXIS DIRECTION 8 A STEP Z_AXIS DIRECTION 9 A DIRECTION A_AXIS DIRECTION 10 LIMIT SW POS A_AXIS LIMIT(Active When High) 11 INP TOOL CH N/C 12 LIMIT SW NEG Z_AXIS LIMIT(Active When High) 13 G61 Switch Y_AXIS LIMIT(Active When High) 14 M4 OUTPUT Y_AXIS ENABLE 15 NONE X_AXIS LIMIT(Active When High) 16 M7 OUTPUT Z_AXIS ENABLE 17 M8 OUTPUT A_AXIS ENABLE 18 GND Any Connector GND Pin For the Pin#11 input(INP TOOL CH), solder a wire, on the LPT Interface DB25, from Pin #15 to Pin #11. This will connect this unused pin.

I was told that I didn't need to plug in the power connector (for 12V), but I'm starting to doubt the validity of that information since it doesn't seem to be working. Although, it's very possible I could be configuring the output pins incorrectly in Mach2.. Which column should I use for my configuration? (I've actually tried both.., but the most I've ever felt is a faint "clicking" in the ( wrong )motor whenever I change direction from the motor tuning screen in mach2)

If I do plug in the 12V, does that mean I have to add 470 Ohm resistors inline with the step and direction inputs on the geckos? (like it says here )

Have any of you used this board before or know how? I know very little about cnc in general, as this is my first time to work with it. So any other tips on how to get this working would be much appreciated.
06-08-2005, 06:32 AM
H500

You need to plug in the connector. It supplies 5v and 12v. The circuit probably uses the 5v only. To be sure, just measure one of the signal pins with a voltmeter.
06-08-2005, 08:23 AM
abasir

You don't need the 12V. The output from the LPT Interface is open-collector (stated in the part decription at mach5products.com), already appropriate for the Gecko. Ensure you're 5V supply to the Gecko is okay.

Without a schematic of the board, it's difficult to indicate the proper configuration for Mach2. May be a high resolution picture, both sides of the LPT interface, will help in trying to figure out the connections.
06-08-2005, 03:16 PM
nickleplated

Actually, the 5V in the power connector isn't connected to anything, while the 12V goes to the two chips.. So I imagine if they need power at all to run, then I'll have to plug in the 12V?

Sorry, I don't have any other pictures of the board, but from what I remember of looking at it and following the traces, it appears to match column 2 better than column 1.

as for the 5v to the gecko, I found a 5V 2A ac adapter and plugged that in. I had originally been told I could just tie the common to the enable, but after reading some posts here, I decided that that probably wouldn't work.

If I end up having to connect the 12V, I may take the unused 5V line and connect it to the geckos instead of using the wall adapter.. would that work?
06-08-2005, 07:03 PM
nickleplated

Got it working!

Man, it felt good to see those motors turn.

I hooked up the 12V and used the second column in the pinout chart.

I didn't use any resistors inline with the step and direction wires.. After reading that white paper from gecko again, I *think* it means you use them if you hook 12V to the common instead of 5V? Or can you even do that?

I also switched my 5V supply from the ac adapter to the pc's 5v, and it worked fine. I'm thinking it might be better for me to have a seperate psu for the 12 & 5v instead of having to have a power wire running from the pc though.

Thanks for the help!
06-09-2005, 01:28 AM
abasir

Let the fun begins ... :wee: