YAFGWT - Yet Another Bleeping Gecko Wiring Thread

[kochevnik]

Why ? Because I just spent 3 hours trying to wire my Gecko 212 the same way as indicated on the various diagrams found here and on the gecko websites - and none of them worked.

It's absolutely BEYOND me why a company with such good products does such a TERRIBLE job of providing BASIC wiring information !!! 95 + percent of users must wire to a parallel port.

Anyways, most of the wiring for the 212 is pretty straightforward - Power on 1 & 2 , stepper motor windings on 3,4,5,6 - nothing on 7, Direction on 8, Step on 9 - Current Resistor on 11 & 12. Not hard to hook any of these up. Use a meter to check which windings are paired with which, and the various resistor values (close enough are printed right on the Gecko cover and covered here on this board several times in depth).

The BIG mystery is where you get +5 Volts, and what to do with #10 on the Gecko (labelled: COMMON).

If you have a newer PC, then maybe the diagrams here work - (but they sure didn't work on my setup), if you have an old PC (mine's an old Dell Pentium something) ALL that you need to do is connect a wire from the #10 slot on the Gecko to pin 18 (or 19-25, they're all ground pins) on the parallel port (you'll need a breakout board to make this simple).

That's it - that's all she wrote. No other wires, no 5V power supply or connecting to game or USB ports, no jumper setting nothing. One damn wire.

My guess is because older PC's deliver 5V on Step and Dir pins from the parallel port, no major contortions are required to get the Gecko to behave.

Now try to find the info about that one little bitty wire anywhere in the Gecko documentation, or for that matter on any of the diagrams on this site. Ha ! I say again Ha !

Anyways, needed to blow off steam and perhaps help someone else in the same situation. Hook that wire up and she sings like a bird.

BTW: nice board, the G212. I also recommend that if you need a cheap simple parallel port breakout, go on ebay and search for user 'carolbrent' - Hubbard CNC Store. they have several different types - I bought one male and one female for $ 25 total and this allowed me to wire 2 of my motors to my Arcsin board (which has a dead Z axis) and the other to the G212. Piece of Pie

[NC Cams]

Sadly, if you don't have a USB, getting 5v with decent current capacity from an 'old' parallel port can be a daunting task without cracking into the case and using a 5v lead from the P/S.

Some guys have used pin 17 (I think) as a 5v source from LPT but it is NOT reliable - some LPT IC's don't have enough OOMPH to drive much more than an LED let alone a Gecko or the 5v you need for all the external stuff. Some have OR'd the output pins together via diodes to a buss but that's not going to give a solid 5v source with decent current.

Sadly, you might have to resort to a wall plug. We looked long and hard for a 5V source for a BTR we were building and couldn't find a way to do it w/o using a wall plug.

We found a cheap 9v one from Digikey and then added a LM2940T5 to give us a nice robust 5vdc source good for about an amp.

[jkeyser14]

Easy questions with easy answers...

Common is also known as ground. And you can't get a +5v supply from the parrallel port, because none of the pins are always +5v, and you can't pull a lot of current through the parallel port.

A good way to get around this is to use your computer's power supply. Take one of the unused power connectors and hook it up to the geckos. Your red wires on the PC's power supply is +5v, black is ground.

[kochevnik]

Originally Posted by jkeyser14 Easy questions with easy answers...

Maybe I didn't make myself clear enough - using an external +5V supply as indicated in several of the diagrams on this site - DIDN'T WORK. Maybe the +5V MUST come from the computer (as keyser14 posts ?)

Very confusing anyways.

[CJL5585]

Originally Posted by kochevnik Maybe I didn't make myself clear enough - using an external +5V supply as indicated in several of the diagrams on this site - DIDN'T WORK. Maybe the +5V MUST come from the computer (as keyser14 posts ?) Very confusing anyways.

CONFUSING? NOT REALLY.

Using an external 5 volt supply, AND A VERY BASIC PORT EXTENDER BREAKOUT BOARD, the software settings for the different outputs needs to be set to ACTIVE LOW.

The 5 (+) volts DC is wired directly to pin 10 on all the Gecko's. The 5 volt common (-) goes to pins 18 thru 25 on the breakout board.

With outputs set to active high, you will have 5 volts on both sides of the opto-coupler LED inside the Gecko drive. UNDER THESE CONDITIONS THE LED IS NOT FORWARD BIASED, AND NOTHING HAPPENS. OPEN CIRCUIT.

With outputs set to ACTIVE LOW, when an output goes low (example: step), the current (flows from common side to positive side) flows from the step pin thru the LED in the optocoupler and to the 5 volts on pin 10 of the Gecko and back to the external supply. Magic. It will work.

If you had a breakout board with good decent drivers, that utilized an external supply, you could set the outputs to active high or active low.

[kochevnik]

Originally Posted by CJL5585 CONFUSING? NOT REALLY. Using an external 5 volt supply, AND A VERY BASIC PORT EXTENDER BREAKOUT BOARD, the software settings for the different outputs needs to be set to ACTIVE LOW. The 5 (+) volts DC is wired directly to pin 10 on all the Gecko's. The 5 volt common (-) goes to pins 18 thru 25 on the breakout board. With outputs set to active high, you will have 5 volts on both sides of the opto-coupler LED inside the Gecko drive. UNDER THESE CONDITIONS THE LED IS NOT FORWARD BIASED, AND NOTHING HAPPENS. OPEN CIRCUIT. With outputs set to ACTIVE LOW, when an output goes low (example: step), the current (flows from common side to positive side) flows from the step pin thru the LED in the optocoupler and to the 5 volts on pin 10 of the Gecko and back to the external supply. Magic. It will work. If you had a breakout board with good decent drivers, that utilized an external supply, you could set the outputs to active high or active low.

Use a good breakout board.
Did it.

+5V external on pin 10.
Did it.

ground from 5V supply to pin 18
Did it.

set ACTIVE LOW.
Did it.

Guess what - it DID NOT WORK.

I may not be a rocket scientist - but I'm not a moron either. And all the CAPS in the world isn't going to change that one iota.

And interestingly enough, my backup board, an Arcsin, functions perfectly with the same wiring, power supply, motors and software settings.

And incidentally, here is a direct quote from the G212 manual -

If the G212 inputs are driven by a source that has only ground available, such as a PC parallel port, move the 4 jumpers on the header so that it looks like the COMMON GROUND setting. Connect the input driver ground to TERM 10 on the main connector.

I don't know about you, but the words 'connect the input driver GROUND to TERM 10' to speakers of the English language would seem to indicate to most people that you might want to be connecting a GROUND wire to TERM 10. Unless the word 'ground' has suddenly acquired a new meaning, I'd say the Gecko documentation, in anyone's world, would clearly qualify as VERY confusing, and also quite clearly, contradict your instructions above - not to mention saying absolutely NOTHING about requiring an external 5V source, or how to wire it up. The Gecko instructions suck - how's that for plain English.

And I'm tired of pointing this out again and again so this is the end of this thread for me.

[CJL5585]

First of all, I am not, nor have I ever been associated with Gecko.

According to Gecko - a common connection can be either + or -.

It is my understanding that the 212 can be configured for pin 10 to be set up as a common +5 volt input or a common ground input.

I have 6 running systems on these type drives.

Good luck with your endeavor.