Advice on smoke detector disabler project

Hey all,

I’m a new guy to Arduino this summer. However, some family mentioned an interesting and easy project. Basically, when we cook, the smoke detect goes off. So, I’m basically putting an IR receiver connected to the Arduino to turn off the smoke detector. I have the 120v line coming from the ceiling going into the NC of a relay (well, I’ve been using a relay module with which has the diode and transistor in it, I haven’t decided if I’m going to use a relay module or build the relay/diode/transistor getup myself) and the C going to the smoke detector and nothing in the NO (because I want the smoke detector to be on unless we tell it to turn off). And my code is super simple which simply triggers the relay when the IR code is received and waits for 30 minutes and returns the relay to it’s original state. I have questions on the final implementation of this.

I’m unsure of how to power the arduino. Right now, I’m considering just using a 12v 1a wall wart and hooking it straight up to the hot and neutral wires coming from the ceiling with the output of the wall wart going to the vin and gnd pins on arduino. I didn’t know if this was safe or even a good way to go about it. I’ve never made my own power supply, and I don’t want to use batteries because the arduino is either going to be in the ceiling or on top of cabinets 8 feet off the ground.

Also, I didn’t know if I should make this on some perfboard with a arduino pro micro or a arduino nano or simply try using just the atmega328 because it’s not doing anything fancy. Any thoughts? Also, any other advice is welcomed. Thanks.

Promini with IR circuit, 5V wallwart. Relay like this http://www.digikey.com/product-detail/en/EC2-4.5NU/399-11046-5-ND/4291112 Use an NPN transistor to drive the coil. Don't forget a diode across the coil.

Or standalone circuit, that'd be easy too, still run run from 5V.

I would get a plug socket at the hardware store and wire it to the wires coming from the ceiling. If you are not sure, have an electrician do it. Get a adapter, 9 volt DC, as there is less work for the Arduino regulator. Plug it in to the socket on the ceiling to the Arduino.

If the wires are on the ceiling, is there a switch on the wall to control them?

Hi, DO NOT disable smoke detectors, place them where they will not be affected by the kitchen cooking.

I have just has my house audited for smoke detectors and they must be placed outside bedroom doors, no requirement for kitchen installations. (In Australia)

If you are setting off the detector in the kitchen then install a ventilation fan or find a place away from the main cooking area. I'd say that much smoke would be unhealthy for you anyway.

Detecting heat and then disabling the sensor, how do you know that the heat is not from an unintentional fire? 30mins and it would be all over.

Never fool with life saving safety detecting devices.

Tom...... :)