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Distribution: Slack, FreeBSD,NetBSD, OpenBSD, Open Solaris, Minix
Posts: 172
Rep:
Parallel Port Power Off
I'm wondering if there is a way to turn power to the parallel port off. I'm drawing 3.5V from the port to power a small circuit, and I'd like to be able to control it's power state. Any help is appreciated.
What pins are you using for power and can you provide a description of your circuit? It is easy to create a program to toggle data or status lines. Google linux parallel port programming for some examples. I also suggest googling for information on how the parallel port works. BTW you can damage the port very easily if you draw to much current.
Distribution: Slack, FreeBSD,NetBSD, OpenBSD, Open Solaris, Minix
Posts: 172
Original Poster
Rep:
I've googled, but I couldn't find a simple solution to just turn off power to the port. I'm using pin 6 and pin 18 (pins 25 through 18 are soldered together). There's no circuit to describe, I'm just fooling around. I'd finished my serial port radio transmitter and I had a few parallel cables lying around and figured I'd give those a whirl.
BTW pin 6 is data bit 4. Its not a matter of turning on/off the port but changing the state of the desired data/status bit(s). The parallel port is a TTL device i.e. A logic 0 is 0 - 0.8 and a logic 1 is 2.4 - 5 volts.
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