AVR USB RGB LED controller

DIGITAL CAMERA Zak Kemble writes:

While working on an update for my CPU Usage LEDs project, I thought why not just make it into a universal RGB LED controller? The CPU Usage LEDs controller took a value between 0 and 255, worked out what colour it should be and then fade to that colour. This was very limiting; changing what colours it used and how it fades required a firmware update. With this universal RGB LED controller the host software does all the work and the controller is simply told what brightness the red, green and blue LEDs should be. To make it as easy as possible to interface with the controller I created a library which deals with all the LibUSB stuff.

Files available on Github.

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    1. I believe the white plastic block is a Molex 8981 power connector (like in a PC), there is no LED actually on the board.

      I didn’t read the whole backlog of blog posts, but judging by the posts’ photos and the schematics and PCB on github, it appears to be intended to be used as a PC case mod.

      The Molex is there to provide a 12V source and beefy ground connection, and an external RGB LED is connected via the 0.1″ straight header along the side, common anode. It switches each of the 3 cathodes with a MOSFET, and has big copper pours, as it seems to be meant to drive a string of LEDs (all the same color). I think it leaves current limiting for the external LED module / string to implement for itself.

      The right-angle 0.1″ header opposite the Molex is the USB connection. Presumably it’s a pin header to allow you to connect directly to a motherboard’s internal USB headers, without bothering with USB plugs.

      1. Oh Dear, What’s Red? How could I not see that before? It looked like a plastic block or similar and I figured it must have been some fancy diffused RGB LED module – Derr! It was late here, that’s my excuse ;) Thanks for clearing that up for me and now I’ll just sink into the background and pretend I’m a Nube :D

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