Very new, very confused ;-)

Hi all,

First post and all that!

I’ve been messing with ADU units and light sensors and other USB type switches for a few years - nothing major, just turning lights on and off etc… and then after buying a copy of Linux Format a few months ago came across an article about the Arduino units.

I would like to experiment but I’m not sure where to start - I’ve been reading round the web a lot, but I think I may have read TOO much and now I’m confused as hell.

I’d like to build something that has a light sensor attached and that turns a light on when and if the light outside gets dark enough to trigger something on the board.

I’m no stranger to programming, and Wiring looks pretty straight forward to me.

Is there a board/sensor that someone could recommend to point me in the right direction for getting started?


Depending on your definition of “light” this is very easy to do with an arduino.

The sensing dark part would just need a light dependent resistor, and it can easily turn on an LED “light” when the ambient levels drop to below a certain level.

If by “light” you mean a household incandescent bulb, it’s a bit more complicated - you need some extra hardware capable of switching the higher 240VAC (110VAC in some parts of the world).

Hi, thanks for the quick reply!

That’s exactly what I wanted to hear!

Turning on an LED would be a great start. I have USB switches connected to 7 PCs in my house, each with a TCP listener program that I have written in Python that turns the switches on and off from any/all of the others, but was looking eventually to automate these and keep them free of the need for a PC in each room(each room has a PC in it in any case, so it’s not realy an overhead).

If I were to build the LED on/off thing, would it be easy at a later date to change that for a switch/relay? If so, then I’m getting really excited. It would seem that it would make it possible to switch a relay to switch a circuit connected to a geared servo to close blinds etc… However, I don’t want to run before I can walk, so turning on and off an LED would be fantastic.

Also, I have found this:

It seems to have a photosensitive resistor in the pack - would this do for a beginner like me?

would this do for a beginner like me?

Yep looks like just the job for you.

For relays look at:-

Fantastic - and thanks for that link too.

I’d rather find a UK supplier, well, I have found a couple, but they are all out of stock - not suprising as they are cheaper and the delivery time is shorter.

I can’t believe how excited I’m getting about making an LED turn on and off! :wink:


I have 50 quid in my Paypal account (I don’t have a bank account, so paying for things on-line is a bit of a nuisence!).

The UK kits fall well within this range, but I can’t find anywhere that has them in stock.

The US one is 8 quid more with the exchange rate - and while I don’t mind paying an extra 8 quid, it takes about 2 weeks to move the money from someone’s account into Paypal, and that’s once I can find someone willing to do it.

Does anyone know of a UK supplier with a kit that is in stock?

This one claims to be in stock tomorrow, but it’s £63.50.

I’d suggest buying a diecimilla/duemilanova from somewhere and getting the discrete components from Maplins or similar.

Edit: just noticed you can remove the board and it’s £16.10 cheaper, but then you wouldn’t have an Arduino…


Hi, thanks for that. I was thinking of buying the board and the resistor seperatly, but I just don’t know enough to trust myself to buy the right things at the moment, hence looking at starter kits.

Thanks for the link though - I have emailed Tinker in the meantime asking when theirs are likely to be back in stock, but have yet to recieve a reply.

Shall I just go ahead and get the board and any photoresistor and a few LEDs?

I can always add to it at a later date presumably?

EDIT: Scratch that idea - I’m just being impatient! I’ll wait for the beginners kits to become available.


I don’t know how Paypal works for the UK, I’m sure it’s practically the same for the US. We have the option to get a Debit card to pay for things directly out of our Paypal account. So anyplace that takes Visa, will come right out of your paypal account.

I went on a cruise about 2 years ago using my Paypal Debit card.

Thanks for that - although that’s the problem, I don’t have a debit card.

In fact, I don’t have a bank account - I have to give money to friends and they upload money into my paypal account so that I can buy things on line - it takes 9 working days (so a minimum of 12 days) here in the UK :frowning:

However, I have convinced my dear old mum to buy the kit on her card and I’ll give her the money tomorrow - so I’ll be making an electronic mess pretty soon :wink:

One quick question though is the Seeeduino board the same as the Arduino board?

This is the kit I’m about to buy; I just don’t want to buy the wrong thing.

The Catalyst Pack with a Seeeduino board are now in stock.

If you order by Tuesday night, you will receive it by Thursday. Just in time for Easter :slight_smile:

Tis done. All bought so hopefully will be delivered before the long weekend :wink:

One quick question though is the Seeeduino board the same as the Arduino board?

It’s like the Diecimilla official board but with some very useful changes/additions, none of which will mean much to you if you’ve not used an Arduino before…

I think that “catalyst pack” looks like a good way to get started.


Hi, thanks for that.

I can hardly wait for it to turn up now - ordered it last night, and they confirmed my address this morning, so it’s looking likely that it will be here before the long weekend.