Problem with printing

Archiver

Dear Friends,

I am an Engineering student and working on few projects right now.
I used the schematic and program given in this website to connect my
printer to basic stamp. The problem is the PIN11 of the parallel
converter from printer. This pin is supposed to be busy pin, but it
is -5v all the time.

For the solution, which I know is not good and correct, I manually
forced the pin to zero volt by connecting it directly to the ground
of my circiut.

Can anyone give me direction or a hint, How to fix this problem?

Thank you,
Nima

Archiver

Oh, dear, I hope you put a 470 ohm resistor in
that line to limit the resulting current.

If you have a voltage you don't THINK should be
somewhere, 'FORCING' it to ground OR VCC +5
with a piece of wire is very bad practice. Things
tend to put out too much current when you do that,
and smoke and die.

If you REALLY feel you must, use a resistor
to connect the two. 470 ohms over 5 volts gives
10 mA -- which shouldn't destroy any circuitry.

A better solution is to find out WHY the output
voltage is different from what you expected, and
correct that. (shorted wires? missing ground
wire? 'non-standard' port wiring? Blown/dead/
shorted circuitry?)



--- In basicstamps@yahoogroups.com, "NIMA" <nimjah@y...> wrote:
> Dear Friends,
>
> I am an Engineering student and working on few projects right now.
> I used the schematic and program given in this website to connect
my
> printer to basic stamp. The problem is the PIN11 of the parallel
> converter from printer. This pin is supposed to be busy pin, but
it
> is -5v all the time.
>
> For the solution, which I know is not good and correct, I manually
> forced the pin to zero volt by connecting it directly to the ground
> of my circiut.
>
> Can anyone give me direction or a hint, How to fix this problem?
>
> Thank you,
> Nima