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Author Topic: Electronic relay control program with web interface  (Read 2722 times)


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Electronic relay control program with web interface
« on: December 08, 2009, 09:47 AM »
I'm curious if anyone can whip up a quick program to control 4 electronic relays via either an RS-232 serial port or a parallel port.  I know, you are likely wondering who in the heck uses COM or LTP ports anymore, right?  The quick answer is, I would like to!

The idea is for me to build and be able to control an outdoors camera mount, so it may tilt up, tilt down, pan left and pan right.  I would love for the control to be done via web interface accessible from anywhere on the 'net, however I would be plenty happy with four clickable buttons in a window.

My thoughts are that one button in the program would control one relay each.  Each relay could be controlled just by toggling one pin in the serial or parallel port high in relation to ground when a button is clicked on, maintain the pin toggled high while the button remains clicked, and then return that pin to 0v when the button is no longer being clicked, that would work.

Electronically, I'd like to keep this project as simple as possible.  By toggling one pin high, I was thinking I could use a power supply and a few transistors between the serial port pins and the relays, to provide and control the voltage used to drive the relays.

My idea is to implement a camera for my community watch along a tree line with a foot path carrying suspect foot traffic.  Pan and tilt would be awesome to include but aren't exactly necessary, so if this can't be done quickly and easily, no worries.

Since we're a not-for-profit group we cannot really afford nifty wireless IP cameras nor any other equipment I would love to see deployed, however I do have a spare sony 1/3 inch CCD camera on hand, along with electronic and mechanical components to whip up both the control and pan/tilt unit.  I will be donating the home brew electronics hardware to the community watch.  If you could dontate the software to toggle some serial port pins high and low, and maybe integrate a web based interface, we would all be thankful.
The Edge... there is no honest way to explain it because the only people who really know where it is are the ones who have gone over.  --  Hunter S. Thompson


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Re: Electronic relay control program with web interface
« Reply #1 on: December 13, 2009, 03:42 PM »
I would check into web cam security software for USB.  Most off the shelf machines now don't even have a parallel port or serial port anymore.  If it has to be for those then your hope would be some retro software.

You might check for Win98 freeware sites with old versions of programs.  When the webcam craze was first kicking in there were lots of sites with web control for aiming the cameras. There must be software out there already debugged.

« Last Edit: December 13, 2009, 03:44 PM by MilesAhead »