Relay source code

**Dexter172** · 09-30-2004, 11:52 PM

Is there any realay source code for the parallel port written in C or make it really simple Basic? There was alot of talk about the relay setups but it never really got off the ground. Just code to read a signal and a code to send a signal to a relay.

**mushin** · 10-01-2004, 03:55 AM

Google for "dlportio", you'll find a C library for raw access to the parallel port under Windows. The code will be *really* basic, since all you're going to be doing is setting particular bits high for each relay.

**god_of_cpu** · 10-01-2004, 09:57 AM

I got a parrallel port based relay card and wrote my own control software using dlportio, the problem is its absolutly unusable in the car since random bits will get sent to the parallel port when booting and trigger the relays on the port. You could perhaps get around this by using a relay to trigger the power going to the parrallel port card only when the computer is finished booting, problem is you now need another relay card to start your first relay card.

**Marsupial** · 10-01-2004, 12:11 PM

what if you use a USB parallel port... it theory it won't send anything to tbe LPT port until the PC is booted and the USB has kicked in... or maybe I am wrong.

just an idea

**Gruneun** · 10-01-2004, 12:22 PM

Do a search for the "Mini SSC II" servo controller card. It's about $40, is a couple inches square, controls 8 servos (chainable up to 256), and takes 3-byte commands from a serial port. There's plenty of free software for controlling it. If you're dead-set on it using the parallel port, you can use an adapter.

**god_of_cpu** · 10-01-2004, 12:39 PM

Originally Posted by Marsupial

what if you use a USB parallel port... it theory it won't send anything to tbe LPT port until the PC is booted and the USB has kicked in... or maybe I am wrong.

just an idea

That would be too easy... I haven't tried it myself but someone else on here said they don't work with the USB converters.