Project Edge Lit Sign - PART 2

The Electronics

This part of the project took me a bit longer than I expected.  I thought I had everything figured out for the design, parts and programming for the micro controller (Arduino Pro Micro) but ran into an unexpected issue that forced me to change course and use completely different hardware along with software libraries I hadn't used before.  Good news is that even with the changes and learning new hardware and software the new setup is actually easier and simpler to wire up and use.

My initial electronic design for controlling RGB LED's for the sign illumination.
Parts:

• 5mm RGB Common Anode LED's 
• TLC5940 shift registers 
• Arduino (Nano on breadboard)
• Resistors for setting current limit

I built up the circuit on a solder-less breadboard to get it working.  Below is the setup from the Arduino Playground.

Wiring for TLC5940

Pictures of the layout:

I transferred the circuit to perf board (laid out the same as solder-less breadboard), cut and drilled out a piece of wood to mount the LED's in my box and wired in a wall wort for power.

All the Parts

Perf Board (back side)

 

Wiring it all up

Software library, further instructions, etc can be found at:

1. Direct link to Google Repository
2. Arduino Playground page for TLC5940

 So, after all that work building and testing - it worked perfect but it just wasn't bright enough for the sign so I had to reboot and go a different route.

Decided to go with Neopixels - much brighter RGB LED's.  Individually addressable for color and brightness, much easier to wire up - just a 3 wire connection to Arduino (Trinket or clone).  Do need real basic power filter (1000uF 6.3v or higher electrolytic capacitor across power rail to filter out spikes) as well as current limit to data line (300 to 500 ohm resistor to keep current at set level).

Currently there are 2 very good libraries (that I know of) for controlling Neopixel's with an Arduino.  I provided links to them as well as guides to using them below.

FastLED

• FastLED_3_0_3
• FastLED-Basic-usage

Adafruit Neopixel

• Adafruit_Neopixel-GitHub
• Adafruit-Neopixel-Uberguide

I'll complete this post tomorrow (Part2b) with the final electronics and code.   

Fume Extractor Build

Since I do most of my electrical soldering at my basement workbench, and there is not much ventilation, I decided it was about time to put something together to take care of the fumes. I came across a Make Magazine Weekend Project Mini-Fume-Extractor  and figured I could put together something similar.

Goals of build:

• Benchtop Fume Extractor
• Powered from outlet, not batteries
• Easily positionable

I have a box full of old wall power transformers left over from old phones and other appliances, as well as another box of fans scrapped from appliances and computers. Searching through this I came up with the following:

The Fluval filter is a small charcoal aquarium filter I found at a local pet store.

Now I just needed something to hold and position the fan, the first thing I thought of was some type of metal gooseneck like on some desk lamps and microphone stands. I did some online searches and found this site Leflexo but they had no pricing (and still haven't answered my inquiry). I also found a nice little inexpensive gooseneck usb light at IKEA USB Light.  I was planning on heading out to IKEA but decided to check my favorite parts supplier first – Goodwill. There are 4 Goodwill shops within 10 miles of me and I lucked out and found a gooseneck desklamp at the one just a mile away and it was only $4.

The lamp had the added benefits of a weighted base (something I wouldn't need to figure out on my own) as well as a built in switch.  The only thing left was a method of mounting the fan to the lamp base.  Cutting, drilling out and gluing together some scrap acrylic solved that problem.

The last pictures are initial testing just to make sure the fan works, I cleaned it up by soldering and shrink wrapping the wires.  In addition I added the clips from the lamp (held on the glass plate in front of the bulb) to hold on the filter.

 

Project Solder Fume Extractor - Quick Project

Picture of Fume Extractor at final testing - still needs soldering and filter added.
Decided to do quick project to add to my electronics workbench - a simple positionable fume extractor.  I'll post a writeup on it tomorrow.