[need help] Temperature alarm

[prestost]

Hello there.

I'm a newbie in electronics and don't really know how to do things. Therefore I need some help.
What I want to do is to have a thermometer, and when the temperature reaches 25°C I want a small strobe to be activated.
It maybe sounds kinda easy to you guys, but I have no idea how to do this and what to buy. I've looked on buying a rasberry PI but a friend just told me that buying a micro-controller was going to be cheaper. I don't want to spend so much money as this is a little bit just for fun. Maximum maybe 100$.

Thank you for your help
Best regards
prestost

 

[redwire]

Try an Arduino with a breakout board for the power supply, temperature sensor, and led (strobe).  Do you know anything about soldering or programming?

 

[Hero999]

Comparator, a few resistors and a relay .