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View Full Version : World's dumbest DB25 (parallel port) Breakout Board?



boldford
10-09-2012, 10:17 PM
DB25 Female Signals Breakout Board parallel port | eBay (http://www.ebay.co.uk/itm/380450316406?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649)

Jonathan
10-09-2012, 11:07 PM
Might as well just cut the end off the parallel port cable and poke it straight into the drivers if you're thinking of getting one of those!

John S
10-09-2012, 11:11 PM
Don't knock them, they have a purpose.
Chop the end off a parallel cable, wire into the connectors 1-1, 2-2 etc and you then have a nice unit to put the scope on for checking.

Got me out the sheite a few times, especially checking for none working charge pump signals on HP computers :concern:

Jonathan
10-09-2012, 11:14 PM
If you just want to run the stepper drivers and nothing else (i.e. no inputs, no spindle etc) and your drivers are opto-isolated, and your parallel port voltage is OK then they're fine.

John S
10-09-2012, 11:18 PM
Nope, missed the point, use it as a special cable, THEN into a proper BoB.
All you are doing is being able to easily access the ports on the computer whilst it's all working.

As I say handy for charge pump problems and return signals for things like encoder return for threading.

We bought out sold as a BoB from Routeout a few years ago

JAZZCNC
10-09-2012, 11:21 PM
Just like BOB BOB BOBBING ALONG. .:barbershop_quartet_

Jonathan
11-09-2012, 12:56 AM
Nope, missed the point, use it as a special cable, THEN into a proper BoB.

Nope, your point was perfectly clear, I'm just talking about a seperate use for it...

Either way the price isn't that great.

boldford
11-09-2012, 09:20 AM
Nope, your point was perfectly clear, I'm just talking about a seperate use for it...

Either way the price isn't that great.I only made my original post 'cos I thought some here might think them to be expensive for what they are and they lack optos.

That raises an interesting question in view of the understood wisdom here that multiple optos are bad practice.
Is it preferable to locate the optos on the BoB or the driver board(s)?

Jonathan
11-09-2012, 09:34 AM
I only made my original post 'cos I thought some here might think them to be expensive for what they are and they lack optos.

Yep, could make and sell that for a fiver and still have enough profit to buy a drink...


That raises an interesting question in view of the understood wisdom here that multiple optos are bad practice.
Is it preferable to locate the optos on the BoB or the driver board(s)?

You generally don't get a lot of choice where to put them since the overwhelming majority of good drivers have them built in already. However if using drivers without isolation I think I'd prefer to have them nearer to the parallel port since the signals from the port are more susceptible to interference between the port and the isolators, since the isolators buffer them. I doubt there's much in it though...