Propagator project - automatically turn on light bulb

Hi all,

I'm quite a newbie with Arduino but keen to do what I think will be a easy hack to build an automated propagator with my daughter.

Essentially I want to create a box with some plants inside, hook up an Arduino controller (Uno) and perform the following:

  1. Monitor temperature (simple, can hook up a temp sensor and use serial monitor)
  2. When temp drops, switch on a light to increase heat in box (not so simple, reading online gets me confused about voltages etc. I am in Ireland so we have type G power sockets, 230v and frequency 50hz according to Ireland - Power Plugs & Sockets: Travel Adapter Needed?.
  3. Soil monitor to display a light when the soil is low (easy, already have a project that does this).

So, basically I am really stuck with how to turn a power socket on and off. I've read about relays etc and looked at some instructables articles but most of them seem to be using different voltages etc.

Can anyone recommend a good option for me here?


This will work

Don’t worry about the different voltage just so long as the relay you use can take the AC voltage and current you want.

Maybe, given your daughter is around the project, something pre-made and safe would be a good idea. Such as this?
s-l300 (18).jpg

s-l300 (18).jpg

Thank you @grumpy-mike for your reply, appreciated. Had I not seen the next message from @paulRB I would have used it, but Paul thanks so much this is exactly what I am after and certainly a lot safer for both myself and my daughter!

Have a nice day and thanks for your time.