Homemade "First Alert" fire alarm

Check it out! I recently got Arduino, which is an electronics developers toolkit. First day I opened it… I made a fire alarm of course! It features a fixed temp heat sensor set at 90 degrees F, as well as a test button.

A 90F degree trigger is really low. That would trigger immediately in the attic at my house in the summer time where it gets to at least 120F. I would recommend a temperature sensor that can use a thermal probe. Something like Thermocouple Type-K Glass Braid Insulated [K] : ID 270 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits and Overview | Adafruit 1-Wire Thermocouple Amplifier - MAX31850K | Adafruit Learning System with this tutorial Overview | MAX31855 Thermocouple | Adafruit Learning System .

You should design it in the program so that it has configurable alarm conditions like 15F/min (rate of rise), 190F (high temp) and 135F (regular rating). from dip switches/eeprom changes/variable changes & reprogram.

Well, of course this is just a prototype. I set it to 90 degrees just to make it easier to test.

Also, the analog input monitor is too noisy to use rate of rise. I tried using the code required 15F/min rate of rise, but it kept going off because the microcontroller isn’t very accurate and even when hooked directly to a resistor, the reading fluctuates by 10 degrees F and sets off the ROR portion. Very annoying. I might need to add some averaging code in there.

I have since added greater functionality and using a bigger case for it.