Basic button + LED

**knubile** · 03-12-2008, 05:24 AM

I'm looking to add a very basic control. A simple momentary button for input and a tri-colour LED for feedback. I'm guessing the simplest way to do this is through the parallel port. I want this as a small device velcroed to my dashboard.

Any suggestions as to how put this together?

**bigbuffs** · 03-12-2008, 11:00 AM

What exactly do you want this button to do?

**knubile** · 03-12-2008, 11:04 AM

I'm going to use it to start recording some data, but I won't have my touchscreen usable at the time. I just need a super simple interface instead.

**tigergibb** · 03-12-2008, 11:32 AM

That'd be a good idea for making a dash cam record

**knubile** · 03-12-2008, 11:37 AM

Yup. Now how the hell do I do it?

I'm sure this is basic high school stuff, but I've never done it. Is there something I can just buy?

**tigergibb** · 03-12-2008, 11:43 AM

From what I understand Girder is good software to use, but I've never used it myself. Maybe someone can step in and help?

**Woofnstuff** · 03-12-2008, 04:26 PM

get a "fusion brain"
http://www.mp3car.com/vbulletin/fusion-brain/

**2k1Toaster** · 03-12-2008, 04:53 PM

Originally Posted by Woofnstuff

get a "fusion brain"
http://www.mp3car.com/vbulletin/fusion-brain/

That is the easiest.

If you want to try and make something yourself, then you can use the parallel port if you actually have one. A USB-->LPT1 will not work.

Also keep in mind that during bootup, both serial DB9 connections and parallel LPT1 connections can and will shoot out random bit sequences until they are loaded. This means if you have just a very simple non-logic circuit on it, you run the risk of mucking it up when the pc boots, so you should have some protection for that. Something like a start communication sequence and the probability of the random bursts equalling that would be lower the longer/more bits the code is.

http://www.epanorama.net/circuits/parallel_output.html