Hillbilly BOB with Gecko 203Vs?

[Mr. Technical]

Has anyone used Hillbilly's BOB with Gecko 203Vs? The Geckos take step/dir, and need a Common line. I don't know where exactly to hook up the Common to on the BOB, and could use some confirmation about how I've got the motor outputs set up as well.

Here's the way I think I need to bypass the optos on the BOB since the Gecko has got optos on-board, and I don't want to slow things down. I think I need to use the circuit labeled Open Collector Supplied Voltage Buffered output. http://home.icx.net/~ashburn/id1.html

A schematic and/or any help would be much appreciated. Thanks!

Ian

[HimyKabibble]

Originally Posted by Mr. Technical Has anyone used Hillbilly's BOB with Gecko 203Vs? The Geckos take step/dir, and need a Common line. I don't know where exactly to hook up the Common to on the BOB, and could use some confirmation about how I've got the motor outputs set up as well. Here's the way I think I need to bypass the optos on the BOB since the Gecko has got optos on-board, and I don't want to slow things down. I think I need to use the circuit labeled Open Collector Supplied Voltage Buffered output. http://home.icx.net/~ashburn/id1.html A schematic and/or any help would be much appreciated. Thanks! Ian

There is absolutely nothing to be gained by disabling the optos on the Geckos, and if you do, you'll likely fry your PC in the process. The common needs to be connected to the +5V on your BOB. STEP and DIR will be active LOW.

Regards,
Ray L.

[Mr. Technical]

Thanks for the quick response Himykabibble, but I need to point out a couple of things. I was not referring to the optos on the Gecko drivers themselves, rather the optos on the breakout board that I got from Hillbilly of this forum. I've been told that "stacking" optos slows things down as well as introduces noise into the equation. Fortunately, Hillbilly's board uses socketed components, which allows the removal and jumpering of the optos.

Secondly, while I believe older versions of the Gecko stepper drivers used a +5V input, the 203V's use a Common terminal which I have learned connects to any of pins 18-25 on the parallel port cable. These are the PC ground terminals, or common for the PC signals.

Finally, the 203V's are different in that the step and direction signals used to drive it are "Active High", where older/other Geckos require 'Active Low'.

I got to speak with Mariss at Gecko directly, and after speaking with him I have no questions left. Man does he know his stuff!!

Ian

[dratypical]

Anybody got any updates on this? I'm trying the same thing and having no luck getting the port to communicate with the 203V's using any number of configurations on the Bob... I can see the switching of direction on the led coming from the port to the board but nothing's working going to the 203v from the board.

Ian what did you find out from Marris?

[Mr. Technical]

Hi dratypical,

I don't remember exactly what I did, but I seem to remember changing out some chips on Hillbilly's board and removing and jumpering the sockets of the opto-isolators. It had something to do with 'open collector outputs' IIRC. I'll try to snap a picture of the BOB that will show the chip numbers I used and how I jumped the opto sockets.

Ian

[Mr. Technical]

I did a little digging, and I found the order from Newark Electronics for the part(s) that I needed to do what Mariss said. It's Newark's PN:67K0988. It's a 14 pin hex inverter that you swap in 2 places (so be sure to order 2 pcs.) They're only $.20 each at the moment. I think that I just jumpered straight across the opto sockets, but I'll confirm that for you. Hope this helps!

Ian

[dratypical]

Ian,

Thanks a ton... so these replace the two ic's on the board I'd assume... just let me know what you did with the opto sockets as soon as you can.

Thanks again,

Peter

[Mr. Technical]

Glad to help. You're correct, just remove the other two IC's that the board comes with and plug these in instead. Don't forget to orient them the same way! (Sorry, don't know how used to electronics you are.)

I'll check to see which way the optos are jumpered on my mill, and should be able to let you know tonight.

Ian

[Mr. Technical]

OK, the mill cabinet is too close to the wall, so it's difficult to open it far enough to get a good look at how I wired it, but I did find some pics that should answer things for you.

The section of the BOB schematic that is closest to what I used is 'Open Collector External Supply Buffered Output'.

A couple of notes are in order:
1) Don't forget to jumper (or fuse) the fuse holder that sits between the opto socket and the screw terminals. I used yellow 24 ga solid wire.

2) Ignore the black wire that is under the purple wire of the left picture. It's actually something else that was routed under the board, and happened to look like it's connected here.

If you match wire colors from the left and right pictures, you'll see that:
output 2A is not connected to anything
output 2B (gray) is DIR
output 3A (blue) is COMMON
output 3B (purple) is STEP

These are just the outputs I picked at random. Whichever outputs you pick for each axis must match the numbers and outputs of Mach's table of course. In an earlier post I made in this string (post 3) I said Step and Direction need to be Active High. Hopefully that's correct!

I hope this answers all your questions, but if not, let me know.

Ian

[Mr. Technical]

Hi dratypical,

How did things work for you with the chip swap/setup?

Ian