Help: Reading from parallel port

**masch** · 07-14-2004, 02:10 PM

Hola

I've been reading a little on the net on how to read values from the parallel port. Basically I want to be able to read voltages from the parallel port. Lets say I apply 5V to pin 1 and 0V to pin 2 and 5V to pin 3 etc, I want to be able to get something like "000101"

The only thing I've come across is:
http://www.zpeng.com/projects_tcl_page.htm

I downloaded the zip file, and copied the .sys file into the /system32 directory as per instructions. But then I dont know where should I type these commands:

load lpttcl
puts [format "Current LPT is at base address 0x%X" [lpt_getba]]

Do I open an ms-dos prompt and type these? I tried but it doesnt understand what "load" means. (I have emailed the writer but till today - no response)

Perhaps some of the gurus here know more about .sys and .dll files that can give me a head start?

**Chairboy** · 07-14-2004, 03:30 PM

That's assembly, you'd need to type 'debug' in dos first.

**Rob Withey** · 07-14-2004, 03:50 PM

Looks like tcl to me.

**masch** · 07-14-2004, 08:15 PM

assembly? tcl? is that english? =)

what do I need to install first before i can install the prog above? (I cant even get past the installation and I still think I can do this reading from the lpt port - such ambition =P)

**Superduck** · 07-14-2004, 09:15 PM

TCL Tutorial
Another One

Otherwise, check out this site for more parallel port FAQ's and information.

Gogle's got lots of information on parallel ports. There might even be something that's already been made for your application.

Do you have any specifics? Is this data acquisition?

Good luck,

Kris

**Rob Withey** · 07-15-2004, 04:45 AM

Originally Posted by masch

assembly? tcl? is that english? =)

Nope. If you wanna program your computer in English, I'm afraid you're outta luck.

Originally Posted by masch

what do I need to install first before i can install the prog above? (I cant even get past the installation and I still think I can do this reading from the lpt port - such ambition =P)

Stop trying to use tcl commands to install stuff...! Install tcl, learn to program in tcl, then try again.

Even better, get a book called PC Intern. It tells you how to read from the parallel port without needing to go through the hassle of learning tcl (which is like cracking a nut with a sledgehammer).

**masch** · 07-16-2004, 10:56 AM

I havent visited superducks site yet, although by skimming it looks liek its not windows, but its UNIX? ack

I did look at the links for M$ windows users, but are there any free ones there? Most are only shareware. I havent really explored it yet, mainly because of rob withey's comment: cracking a nut with a sledgehammer.

All I want to do is have lets say 6 wires. Each wire can either be 0V or 12V. The parallel port should be able to listen to the 6 wires.. wire1, wire2, wire3, wire4 wire5 and wire6. If there's 12V on wire4, then i want the parallel port to return a value to the computer: 000100, and if theres 12V on wire4 and wire6, then the value should be 000101. I hope you get the idea.

I dont know if this is even possible

**frodobaggins** · 07-16-2004, 12:26 PM

http://beyondlogic.org/porttalk/porttalk.htm
http://hjem.get2net.dk/villy/vje_vbio.htm

**masch** · 07-16-2004, 01:55 PM

Hehe, thanks Frodo, great links. Too advanced for me really. The first one actually just tells me what I need to isntall to get port access from WinXP. The second would have been a great link, provided any of the links to the diy projects worked.

This is actually harder than I thought? I first need to get an analog-digital converter?

**masch** · 07-16-2004, 02:12 PM

btw, this schematic found on this page is how I got the idea I could use the parallel port to detect events and run different functions depending on which switch was flipped:

http://www.fortunecity.com/bally/wex.../ximppar1.html

There was no need for an analogue-digital converter for this no?