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ingenium
10-20-2004, 04:50 PM
hi,
i am facing a peculiar problem. i had once wrongly gave signals to the parallel port through a program, when the scanner was connected through parallel port.
so, something went wrong and now, i am not able to read signals through the parallel port properly.
i read the 5 volts in a multimeter, when the encoder is not connected to the parallel port. but when i connect the parallel port, i even do not detect the signal in the multimeter. however, a weaker signal is generated. of say 1.2 volts... approx. a real unusual behavior... right? give me some idea...
Subhasis

ice
10-20-2004, 11:39 PM
Ahhhhh....that's what i dread...well for the port anything above 2.4 volts means a logic 1...
Is ur scanner working...if that's good ur port's good...
give u a tip...but the tip will cost you 700 Bucks...
Buy a parallel port card.
I have blown 3 serial ports and 1 parallel port till date 8O
You get these cards which fit in your PCI slot..they have 2 serial 1 parallel....no of combinations...ask ur dealer...or check baazee..
-ice
//Gerry

ingenium
10-21-2004, 12:37 PM
well...
i changed the pin.... n it is working fine.... how cud it be.... i pin damaged..... well.... i ll buy that card soon....
hey tell me, where did u get that book serial port complete??
jan alexin.... i guess is the author....
i want that book, n tell me some good book to learn the fundamentals n practical aspects of some good microcontrollers....
Subhasis

ice
10-21-2004, 04:10 PM
yup...pins do blowout...i had the problem with a PIC programmer...figured it out after 5 hours of struggling....
All of Jan Axelson's books are available in India...the serial,parallel and USB nad the micro book...and some othes..i think..
Penram International Publishing handles it..their mail id
penram@bom3.vsnl.net.in

ice

ingenium
10-21-2004, 04:39 PM
thank you gerry....
i think, there might be an office in new delhi too....
Subhasis...

11-10-2004, 03:57 AM
yup...pins do blowout...i had the problem with a PIC programmer...figured it out after 5 hours of struggling....
All of Jan Axelson's books are available in India...the serial,parallel and USB nad the micro book...and some othes..i think..
Penram International Publishing handles it..their mail id
penram@vsnl.com and site is www.penram.com

ice

11-13-2004, 12:29 AM
Ahhhhh....that's what i dread...well for the port anything above 2.4 volts means a logic 1...
Is ur scanner working...if that's good ur port's good...
give u a tip...but the tip will cost you 700 Bucks...
Buy a parallel port card.
I have blown 3 serial ports and 1 parallel port till date 8O
You get these cards which fit in your PCI slot..they have 2 serial 1 parallel....no of combinations...ask ur dealer...or check baazee..

Or go to
http://www.penram.com/PC-Communication/Parallel-Port-Complete.asp
-ice
//Gerry

suniljha
11-13-2004, 09:39 PM
For PIC, The best book I found is:

Design with PIC Microcontrollers - John B. Peatman
Pearson Education Low Price Edition
Cost < Rs. 200
Available as Indian Edition

Sunil

vidur
02-17-2005, 10:09 AM
If i got this right,

when you connect a circuit that you built to the port, you get a lower voltage read out... is that right

if so, check your circuit for short-circuiting, or drawing excessive load current from the port's drivers....


Also Try using external pull-ups


If a port is blown up, you will see that your scanners or printers wil not work

These stuff are pretty robust, I've fooled around mine a million times, often short circuiting a HIGH line!...but it's still A-OK

Vidur

holycow
05-22-2005, 10:14 PM
Ahhhhh....that's what i dread...well for the port anything above 2.4 volts means a logic 1...
Is ur scanner working...if that's good ur port's good...
give u a tip...but the tip will cost you 700 Bucks...
Buy a parallel port card.
I have blown 3 serial ports and 1 parallel port till date 8O
You get these cards which fit in your PCI slot..they have 2 serial 1 parallel....no of combinations...ask ur dealer...or check baazee..
-ice
//Gerry

Hey ICE, where can I get those Parallel port cards? (I mean are they standard equipment, which I can find in any decent computer shop?) Also I have heard that the cards which fit in the ISA slot alone are good for electronic hobbists.. whereas the ones from PCI do not work for our job.

Also one last thing, if I mess up with the circuit, in the worst case, the Card fries, but not the MB right? or are there even worse cases??? (surely I wont jack it to the wall outlet....)

ice
05-22-2005, 10:38 PM
Holycow,

I got mine from a local dealer for 700bucks..worth the dough..
i bought a PCI card having 2 serial ports and 1 parallel port.

Now my PC has a total of 2 PPTs and 3 Serial ports.


Also I have heard that the cards which fit in the ISA slot alone are good for electronic hobbists.. whereas the ones from PCI do not work for our job.

PCI works good enough,you dont have to worry abt it.ISA is old stuff.i run most of my prgrammers thru the card.I even connect my cell to the serial port ,works good.You just have to select the proper COM/LPT port numbers in your application..like COM1,COM2,LPT1,LPT3


Also one last thing, if I mess up with the circuit, in the worst case, the Card fries, but not the MB right?
No i dont think the MoBo will blow if u screw up your card ports,because they are buffered.
Its a good investment..


You may try querying ebay india for cards..but the best buy is from your local dealer.If the card screws up,you can replace it in no time..

holycow
05-23-2005, 12:43 AM
Thanks a lot ice. that sure helps. I will try to get it from the local dealer. BTW is there a good company which makes those cards or anything is fine?

(Maybe does not matter much, as I expect to fry it in < 2 months with my ignorance :lol: )

Thanks once again man.

ice
05-23-2005, 06:09 AM
ur welcome


is there a good company which makes those cards or anything is fine?

I've got a Netmos PCI card.


Maybe does not matter much, as I expect to fry it in < 2 months with my ignorance
I tried doing it,but was unable too.And each time i figured i wired the port wrong,my sinoarterial failed to keep my heart thumping for a sec or two.
scary at times,but you learn alot this way.