[beginner]Arduino/12V-lights

Hey everyone!

yeah, i'm a total rookie in the arduino-world. Though I've been working with Max MSP for a while (and other programming-stuff for a longer while), i'm completely new to the whole "real-tech"-stuff.

We're making an interactive installation that involves a set of 8 buttons. We've got these kickass things. There connected with a i-pac 2 and all that works great :sunglasses:

The cool thing about these buttons is that they came with these 12V lights and off-course I wanna make use of those.

So: I want to control a set of 8 12V/1.2W-lights (independently) from Max/MSP and I don't have a clue where to start. I'm considering to order this Arduino starterskit that contains an Arduino Duemilanova (Diecimila). Is that ok for what I'm building, and what hardware would I need besides that? And what would be the ideal approach in general for getting this to work?

Thanks in advance,

Jasper (Amsterdam-Holland)

The biggest thing you are going to need is a 12V 1A power supply to power the Arduino.

the lights are going to draw about 800mA of current so 1A is good to power the lights plus the other peripherals.

You will also need 8 NPN transistors to switch the Lights on and off

You will also need 8 NPN transistors

Or maybe a chip like the ULN2803.

Or maybe a chip like the ULN2803.

Yes but at 100mA per light that means if all 8 are on it's 800mA which is too much for this chip. Maximum total is only about 600mA due to heat dissipation. You could use two though.

i'm sorry, can we take a step back? I'm not very familiar in this area.. :-?
The starterskit comes with a 12V-powersupply, does this mean that the Arduino will pass this power to the lights, or do these lights need there own powersupply?
And besides that, I think I would get my around this a lot easier when I see it. What would be a regular scheme to make this?

Anyway, thanks a lot for your help!

Take a look at this circuit: http://www.arduino.cc/playground/uploads/Learning/solenoid_driver.pdf

You will need to power the arduino with the power supply you recieved with the kit.

The TIP 102 is a darlington transistor. The solenoid should be replaced with one of your lights. I don’t think you need the diode.

The solenoid power V+ is the VIN putput on your arduino. You don’t have to worry about the solenoid ground.

You can use any digital pin to control the output. Making the digital pin high will turn the light on, making the digital pin low will turn the light off. If you use one of the PWM pins you can control the brightness of the lights as well.