GSM Dialers for household alarm systems cost a lot when compared to the cost of a mobile phone. I believe it should be possible to program up a single chip micro to issue AT commands to a regular phone in response to an alarm input.
Anyone know if this has been done or if there is a design available?
Is this the sort of thing? A contact opening or closing will send a GSM message all for £16.
If I remembr correctly it has four inputs and eight outputs so you can send it a text message and turn things on or off as well.
send
Perfect thanks that's exactly what I mean. The comercial units sold for alarms are around £200+.
If you get the right phone it will even do 'intelligent' charging. Only charging when the phone gets down to one bar or when it is about to send an SMS. Password protection if you want it. Needs a serial rather than USB data lead for the phone which seem to be a bit rare these days. I've become a great fan of Jaycar Electronics. I reckon the price for this kit is extremely good.
Most nokias use a serial connection - they connect direct through onto pads on the circuit board under the battery. The phone handles the rs232 signals directly. I got a lead for £5 from my local market (for a 3510).
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