Hey,

I am working on a project where I need to link a scroll wheel (from a mouse) to enable it to turn on 3 LEDs in succession, and then work in reverse to turn them off. It would be something like this:

http://www.youtube.com/watch?v=ynw254eBSeo&feature=related

I was advised a bar graph would work best but I can't figure it out. The chip and the way the circuit works seems a bit confusing for a n00b like me.

Anyway, would be good to get some help if anyone knows how I could achieve this. I need to use some micro leds, 3mm ones with a flat top.

Cheers

 

There is no correspondence between your idea and the video. The video shows a potentiometer putting a varying voltage to an IC like an LM3914. The output from the mouse is a digital pulse train.

The closest you might come to the scroll wheel idea is to find a potentiometer that has a thumb adjustment. Mouser has a number of sch pots in it's catalog on page 686 - they are by Bournes, try searching on Mouser part #652-3352H-1-203LF.

There are numerous projects on this site that deal with LM3914's. One of them plus the external parts will let you control up to 10 LED's.

 

There is no correspondence between your idea and the video. The video shows a potentiometer putting a varying voltage to an IC like an LM3914. The output from the mouse is a digital pulse train.

The closest you might come to the scroll wheel idea is to find a potentiometer that has a thumb adjustment. Mouser has a number of sch pots in it's catalog on page 686 - they are by Bournes, try searching on Mouser part #652-3352H-1-203LF.

There are numerous projects on this site that deal with LM3914's. One of them plus the external parts will let you control up to 10 LED's.

There is no direct reference, correct, but the idea is to connect the scroll wheel to the poteniometer so as the wheel scrolls, so does the potentiometer.

 

Then it is a purely mechanical challenge - altering the mouse so as to place a pot in it coupled to the scroll wheel. It may be harder than you think. And I assume you don't care if the mouse still functions after the surgery.

 

Then it is a purely mechanical challenge - altering the mouse so as to place a pot in it coupled to the scroll wheel. It may be harder than you think. And I assume you don't care if the mouse still functions after the surgery.

Basically I have a mouse wheel which runs along a shaft, the shaft is then glued to the pot's control knob.

Yeah, I dont care if the mouse is busted afterwards, it was only a cheap one

 

If the requirement is to use the mouse wheel, I strongly suggest abandoning the bar-graph and instead using some kind of counter.

You'll need to read up on "quadrature encoding." Using that phrase in an internet search will yield what you want.