I've been looking for ways to detect instances of tampering for our fire alarm detector units. I've already thought of using a tactile push switch or putting two conductive objects together and allowing Arduino to check if they are placed apart when someone opens the case.
I've also read about safety interlock switches. But is there any smaller, cheaper and more efficient means to detect tampering?
@ardly
Each detector is actually independent and consists of a Pro Mini, an XBee, some sensors and other circuitry. It just sends an alarm towards the monitoring center wirelessly. It's an IoT-based system btw. Did I get your questiin right?
Any (micro)switch will do, but... switch contacts that are not used frequently oxidise over time, and might fail.
That's why alarm systems use magnets and glass encapsulated reed contacts.
If you use a microswitch, use it in 'normally closed' mode, so when the contact fails it also sets off the alarm.
Leo..
rayrayrayyourboat: @ardly
Each detector is actually independent and consists of a Pro Mini, an XBee, some sensors and other circuitry. It just sends an alarm towards the monitoring center wirelessly. It’s an IoT-based system btw. Did I get your questiin right?
Yes you got my question. Your original post did not make it clear that you had a IoT based system with WiFi. I was thinking you had a basic off-the-shelf system so wiring the detectors back to something or adding a processor with power supply and coms (and fitting it all into the existing detector) would be fairly impossible.