Driving multiple LEDs with a NXT block?

[Lego Otaku]

I wanted to drive 7 or 8 LEDs from a single NXT block. But searching hasn't given me a good answer other than a $50 part: https://www.hitechnic.com/cgi-bin/commerce.cgi?preadd=action&key=SPR2010

Is there an cheaper way to do this? That is cut off one of the cable and use the power, ground, and 2 motor control line to a multiplexer and use that? I have several electronic components that I can use.

Also is there a forum that is better suited to getting the most out of NXT than this one?

Edited May 10, 2012 by Lego Otaku

[DLuders]

You may want to ask your question on the Mindboards Forum. You could also make your own NXT-compatible stuff by following Philo's suggestions.

[dhc6twinotter]

Are you wanting to control each LED individually, or is it ok for them all to go on/off at the same time? If you want them all on/off at the same time, you could use the RJ45 to old style 9V plug, then use the PF extension cable to plug in a set of PF LED lights (assuming you're using PF LED?). You could stack 4 LED lights on top of each other to get the 8 LEDs you want.

So, you would need this:

Then plug in this:

Then your lights, with the plugs stacked on top each other.

I've never tried it, but I'm assuming it would work. Maybe somebody with more NXT experience than I can verify.

[Lego Otaku]

I wanted individual control so looks like Mindboards forum it is.

[dhc6twinotter]

I wanted individual control so looks like Mindboards forum it is.

Yeah, sorry I can't help you there.

[ciken]

you can hook up a microcontroller up via I2c

example for arduino

connect like this connection

[DLuders]

@ Lego Otaku: Besides HiTechnic.com (which you already know about), have you seen the NXT products available from Mindsensors.com? What about this 8-LED Brick Lites kit available from Artifex Creations?

[Lego Otaku]

I've seen those lites kit on eBay before but it doesn't look like it can be connected to NXT to sync the light sequence with the motor operation. It would look somewhat random with those lite kit and NXT running other stuff.

Mindsensor did have something that will likely work, the magic wand.

[Burf2000]

If I remember you can control 2 led's off 1 power function motor channel so forward does 1 and backwards does 1. I believe it is a cable mod. If you then used a Hitechnic IRink you could control 16 lights, so 4 channels * 2 motor per channel * direction (2).

I am sure someone has shown me this. You would also have all your NXT motor ports spare