Need Help!- Parallel Port on Laptops

[karl1]

I hope I'm not posting something that has already been discussed, but I was looking for some sort of adapter to shift the lower voltage logic (3.3v) of a laptop's parallel port to those needed by (most of the) controller boards out there. I'd even consider a commercial "box' if available. If there isn't an open source, then I would look into building one of my own design, and would post it if there was an interest. Does anyone else have the same problem with the lower voltage interfaces, especially laptops and newer desktops?

Thanks!

Karl

[LeeWay]

My Toshiba Satelite didn't have a port. My Thinkpad did, but ran the machine like crap. Possibly due to the low voltage thing. I only used a basic breakout board though. I think some of the Bobs they sell have a feature to increase the voltage and milliamps to useable amounts. I can't confirm that though.

[Greolt]

Most of the commercially available BOBs will handle 3.3v printer ports.

Have a look at this one as an example.

http://tinyurl.com/2qjbb6

Greg

[karl1]

Thanks for the leads! At least I know I'm chasing down a LVTTL issue; I too am using a Thinkpad. My BOB was one I aquired from PMINMO last year - worked fine until I switched from Desktop to Laptop. I might kludge together an isolated BOB based on one shown in PMINO's website, but using the Fairchild FOD063L as the optoisolator, instead of the HCPL26xx shown. I'll post my results!

Thanks!

Karl

[eSilviu]

Originally Posted by karl1 I hope I'm not posting something that has already been discussed, but I was looking for some sort of adapter to shift the lower voltage logic (3.3v) of a laptop's parallel port to those needed by (most of the) controller boards out there. I'd even consider a commercial "box' if available. If there isn't an open source, then I would look into building one of my own design, and would post it if there was an interest. Does anyone else have the same problem with the lower voltage interfaces, especially laptops and newer desktops? Thanks! Karl

I think this will help you.
With 2 of this IC it's possible to solve completly the problem.

http://www.analog.com/en/prod/0,,768...DG3308,00.html

problem: IC is SMD, and for PCB you will have to use Positiv20 or tonner transfer method.
if you need help with schematic or PCB send-me a mail.
Cheers!