Homer said:
Hi All,
I am trying to connect my Three-StepperMotor Controller to my PC via
Parallel port. But whenever I connect it, it heats up and two of those
stepper motors jam (I can't move them by hand).
I found out that if I go to my PC's BIOS and change the LPT1 mode from
EPP to something else, only one stepper will be jammed (if I change it
to Bi-Di system doesn't boot!!:Asus A8N-VM CSM/NBP)
Windows version I am using is XP and no printer is installed.
I have another PC with Win98 installed on it. If I connect my
controller to that PC, everything works fine with no problem.
Anybody has any idea?
I'm not sure if this is the problem you are having but XP does something
strange with the ports. I'm not sure if its port mapping because of
protected mode or what but from what I have read one needs to use a special
driver to get at them. One has been mentioned here but there are several.
They allow you direct access to the parallel ports(and I suppose serial if
you want) and then its like one is running in dos except for the timming
issues due to multitasking(and by having an optimally configured system you
can get close to the performance of dos(if not better in some respects)).
One thing I have read is that one shouldn't used the ECC mode for parallel
ports. It does something funky in XP or causes some problems with simple
communication.
Also, if you plan on driving large loads you have to use a seperate power
source and driver. The ports cannot source much current and will lock up if
they try, atleast I think ;/ I believe the max current they can source is
about 25mA's or so. I'm not sure if this jives with it working in 98 but not
in XP but it could(as XP might do something else).
Why not try to drive LED's or osmething instead and see if that works? If
its the same problem then maybe its the code? If not then its the hardware.
Oops, you are trying to interface a controller with the parallel port. If
this controller doesn't draw much current then there should be no reason why
it would heat up(hopefully you are not trying to pull the current from the
pp to drive the motors). Maybe a stupid remark but make sure your
connections are correct. Its kinda hard to say what could be wrong without
know exactly what you are doing. It sounds like if it getting hot then its
probably a problem with the hardware because even using the ports wrong
shouldn't cause it to heat up. The only way it can heat up is if its pulling
to much current... but surely the controller doesn't use that much current?
(which means you got something wrong) If you can't figure it out then you
might want to post a schematic or even a photo of what you are doing(as you
might have hooked up something wrong).