Will the arduino pro mini 05 handle my project?

Hi all.

I’m currently having a play creating a home lighting automation system. I was going to try and replace all the light switches with capacitive sensors (a few to control the dimmer, and another that’ll trigger the main relay), and relays.

I’m planning on using the arduino mega as the main board, ethernet shield connected to the router, and controlling it with an android app. The others I want to put in the wall of sight, and triggered with the cheap RF transmitters.

So my question, can this:

Handle one or 2 relays, 5 cap sensors, RF transceiver and a small LED?

Or is it too much for the little board? I wanted something small, and I could solder the wires to, just make it a little more robust.

Thanks for the help in advance.

Yes, and a lot more besides, but will need some support chips. You will need to provide it with suitable power and be able to connect a usb to serial adaptor when you need to program it. To drive relays you will need to add transistors or a uln2803 for example.

Cant say about your touch sensors without a link to the data sheet or something. I'm not an expert on wireless, but for interfacing with an android phone, a bluetooth module would seem appropriate.

Finally a word of warning: projects involving mains powered devices should only be attempted by experienced/qualified persons. There are the obvious dangers of elecricution and fire!


Thanks for the response, I wasn't sure if it'd overload the little guy. I'll buy away.

I've gotten all the parts to work individually on my uno, just getting it all together in one sketch will be the fun part, with RF controlling it from the main one.

I've got the ethernet shield, and the android connects to the net (I'm using an app called home ctrl 28, it allows for swipe switches to control servos, and controls lights easily enough, plus allow me to turn on outside lights while I'm driving home.).

Power I was planning on hacking up a 9v wall wort, wiring it to the right pins, and I've found plenty of advice on how to program the little guy.

The cap sensors I'll be using a conductive paint :http://www.bareconductive.com/

Paint it on, paint over it, and it works like a charm. All hidden too. Then I'll paint in a pretty paint some sort of light bulb on the wall. Should confuse everybody quite well.

Thanks again.

Well, in the microcontroller is the same as on the uno board, so its cababilities will be the same. Watch out: its 5V regulator may not be able to supply as much current as the larger one on the uno board. It may be as little as 100mA, so check the description carefully and do the sums in terms of how much current you will need in total. If you need more, just add a 7805 regulator (good for 1A) and bypass the pro's regulator. The major current consumers may well be the relays. Depending on their coils you may be able to drive them using the 9V supply, reducing the need for current at 5V.

Your other option could be to use an atMega 328 and use the uno as an isp programmer to get the sketch onto it.