Society of Robots - Robot Forum

Software => Software => Topic started by: neo01124 on May 28, 2008, 06:55:28 AM

Title: toggling leds using usb to parallel converter
Post by: neo01124 on May 28, 2008, 06:55:28 AM

i want to control around 4-5 digital pins using a laptop(without a native parallel port) so i thought i'd plug in a usb to parallel port converter and then it appeared like a generic parallel port on my machine (lpt1) so i used ouportb command to give it a byte of data but it wont just work. Either all the data pins are on at once or off at once.
Apparently it seems the converter is only meant for connecting a printer.

any help to toggle individual data pins(pins 2 - 9) of the parallel port will be appreciated

Title: Re: toggling leds using usb to parallel converter
Post by: RobD on June 05, 2008, 05:33:58 PM

usb sends data in packets of 1uS or 125 uS and there are probably latency issues with your toggling individual bits.  Most generic usb to lpt converters dont offer work-arounds.  They are designed to drive printers. 

Try looking here for some info

http://www-user.tu-chemnitz.de/~heha/bastelecke/Rund%20um%20den%20PC/USB2LPT/index.html.en (http://www-user.tu-chemnitz.de/~heha/bastelecke/Rund%20um%20den%20PC/USB2LPT/index.html.en)

I'm sure there may be a softwre driver/solution out there somewhere on the web...it seems like the real trick is on the windows side of things.  Thats about all I can offer.   

Title: Re: toggling leds using usb to parallel converter
Post by: airman00 on June 05, 2008, 06:28:44 PM

*cough* use linux *cough*

if you use windows then download roborealm , it allows easy control of the parallel port

http://www.roborealm.com/help/Parallel_Port.php