SX28 Security Control Panel Updated
skynugget
Posts: 172
A good friend of mine recently had his small record store robbed. He had a broken system in place, turns out it all works except for the control panel. The intent of this project is to control all of his security sensors already in place (a controller swap of sorts). Its a no frills alarm system that monitors 8 zones for open relays (zone 1 door chimes), and arms and disarms via a momentary toggle switch and RFID. The alarm condition basically just switches a relay wich sounds an alarm and keys a 2-way for self monitoring (there is no phone or net at the store).
It can be built from radio shack parts in a couple hours (for all of 13 bucks, not including rfid which goes for 50ish i think), its fairly simple. The code is ugly, but i had to get it done quick, and I'm not very proficient with the SX yet.
Special thanks to JonnyMac for writing the SX RFID Routines that i obtained from the demo. As always, if you played with it and made it better, please share with the rest of us [noparse]:)[/noparse]
Post Edited (skynugget) : 5/31/2009 4:36:44 PM GMT
It can be built from radio shack parts in a couple hours (for all of 13 bucks, not including rfid which goes for 50ish i think), its fairly simple. The code is ugly, but i had to get it done quick, and I'm not very proficient with the SX yet.
Special thanks to JonnyMac for writing the SX RFID Routines that i obtained from the demo. As always, if you played with it and made it better, please share with the rest of us [noparse]:)[/noparse]
Post Edited (skynugget) : 5/31/2009 4:36:44 PM GMT
Comments
After some real world testing I have updated the code and posted the schematic.
DISCLAIMER: I am not a trained Design Engineer/Alarm Technician and this is definitely not UL approved. Make sure you fuse the A/C and Battery to suit your needs.
Things I would do if he cared:
Display: I would have added an LCD, but hes cheap
There is no cut wire supervision, his wires and box are well hidden and his sensors are tamper resistant. Real alarms have a comparator input and they hang a resistor across the sensor output. I was going to try to use RCTIME using the capacitance of the wire run to emulate that sort of supervision. I'm not sure if that would work or not.
Power Supply: I would have just used one of those little 3 amp radio shack power supplies - but he is cheap. I'm not to fond of the lm317 circuit i used, it gets hot and if you need to charger over 1.5 amps you are out of luck. Any improvement suggestions here would be much appreciated.
Post Edited (skynugget) : 5/31/2009 5:40:15 PM GMT
Too cheap for an LCD? How much did the robbery cost him? For another measly $15, your friend could have a much more user friendly alarm system:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/lcd/List/0/SortField/4/ProductID/53/Default.aspx
This even has 4 push buttons already on it!
Thanks,
PeterM
Post Edited By Moderator (Bean (Hitt Consulting)) : 6/4/2009 11:41:15 AM GMT
lm317's usually get hot after a while, but if you use a big enough heat sink, they do just fine.
Without the heatsink they tend to fry over time.
Even if you just bolt some large metal washers to the lm317, that might be a good enough sink.
If you can't touch the electronic chip or heat sink, its too hot, get a bigger heat sink.
You can also try to find a wall wart that has the proper voltage and amperage, they are usually cheap, and have all u need.
Many people have old electronic devices that died, but still have the wall wart.
I see you need 13.8v. Tons of laptop power supplies do exactly 13-14v and around 4amps.
You might be able to use a PC power supply also? But it only has 12v, no 13.8...
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Meh. Nothing here, move along.
Post Edited (BPM) : 6/4/2009 12:34:32 AM GMT