In this episode Shahriar takes a close look at programming the popular NeoPixel RGB LEDs using a PIC microcontroller and C-language. A close-up of the NeoPixel (WS2812) LED is shown with attention to identifying various semiconductor elements inside the package. The principle operation of the LED is the described along with a detailed explanation of the pins and the one-wire communication protocol.
A simple evaluation board for the PIC18F4550 is used to drive a circular array of 60 NeoPixel LEDs from Adafruit. After presenting the difficulties of providing an accurate pulse-shape using the C-language, the measured waveform is shown on a Tektronix MDO4000B. Finally, the code for a circular color rotating pattern is presented and demoed. The code for the experiment can be downloaded from The Signal Path website.
Tutorial on Programming the NeoPixel (WS2812) RGB LEDs - [Link]
Pup05 shared his SmartMatrix project. He writes:
The panel fits perfectly, just had to shim it with a little bit of folded card stock on each side. There’s plenty of room for the Teensy and SmartMatrix board, wiring, SD card, etc. I cut out a piece of white printer paper to size, and placed it between the panel and the glass for a bit of diffusion. The magnetic feet that came with my panel from Adafruit fit perfectly, and keep the panel pushed against the paper and glass. I cut a notch in the bottom of the back, just big enough for the power cord, USB cable, and IR receiver.
I loaded up Craig’s LightAppliance sketch and made a few minor modifications, loaded up my SD card with the animated GIFs I wanted, and everything works great. Unfortunately, I already had my Teensy soldered on to the SmartMatrix board, and didn’t feel like pulling it off to solder the RTC crystal on to the back. I might do that later, and add the temperature sensor.
SmartMatrix project - [Link]
by Daniel @ nupo-artworks.de :
I started this project 2 days before we went to France for a 2 week holiday but since this is a really quick project the lamp worked fine after 2 days. Now when we came back I gave it the last touches and finished some bugs in the software.
Initially this lamp should be a replacement for a lamp in our living room but I was way too greedy with the WS2812B LEDs. Eventually, the lamp wasn’t bright enough so I’m going to mount it now in the sleeping room as one of those morning, sun imitating lamps. As a controller I’m going to use a Raspberry PI with a node script that will also control some other devices in my house like my Wall Clock.
IKEA ceiling lamp LED modification - [Link]
Ondrej Karas of DoItWireless writes:
This is simple illustration how to build easy PWM LED control with IQRF TR module and a few other components.
This device is powered from 12V/6A DC power supply and can power up to 5m of LED strip. This device can be controlled via RF, buttons or potentiometer. RF controlling is compatible with remote control device RC-04 with low battery signalizing – fast 3 time LED blinking.
RF PWM LED control - [Link]
ElecFreaks @ elecfreaks.com writes:
We were just wondering in the current market where capacitive touch screens, resistive touch screens, TFT displays are flooding, DIY enthusiasts have been rarely used dot matrix screens. Here we use 5mm 8 * 8 dot matrix screen and phototransistor to achieve a pen write function. Sounds fun? But how to specifically make it? Can we achieve a larger area pen write?
Dot Matrix Pen Write Screen - [Link]
Jack Arcade @ jameco.com writes:
Flashlights are always useful especially if you like to camp like me. Out in the woods, when you are away from your iPhone flashlight, a Mini Maglite comes in real handy. Now, what if you hate its yellow color and carrying extra batteries? What if you want a white color for your flashlight and a longer battery life? Sound exciting? Let’s make one.
Convert Your Mini Maglite to LED - [Link]
Another Instructables by Jan Henrik, a police light with a Attiny25/45/85. He writes:
Hello, in this project I want to show you how to build a multi functional Police Light with a Attiny25/45/85 .
It will have several animations , which can be changed with a button on the circuit board, it has 2 channels, which can be controlled with PWM. That allows us to add serval animations or police light flashing sequences. The maximum rated current per channel is 500mA, that allows us to control high power LED´s, LED stripes or old Light Bulbs!
Attiny25/45/85 police light with Arduino - [Link]
An Arduino, some addressable LED’s, a bluetooth module, code and a 3D printer come together to make blueShift – An OpenXC LED Tachometer. blueShift is so named for the Bluetooth protocol used for data communication, and the use of a tachometer to indicate when to shift your car. It may be amusing to note that the driver and passengers traveling in this car would observe Blueshift when peering thru the windscreen, provided their velocity was sufficient.
blueShift – An OpenXC LED Tachometer - [Link]
by beardedinventor @ instructables.com:
The ISS Overhead is an ambient display that glows whenever the International Space Station is flying overhead.
It is designed to act as an occasional reminder that there are people living and working in space!
This project should take you somewhere between 2 hours to an afternoon to complete. It assumes you know how to solder, and are somewhat familiar with Electric Imp. If you haven’t worked with Electric Imp before, I recommend you get a basic familiarity by working through Electric Imp’s Getting Started Guide before completing this project.
ISS Overhead - [Link]
Here is a small personal project to brighten my home made from a cheap IKEA photo frame, and Arduino and a multicolor “NeoPixel” LEDs strip. The goal is simple: to realize a matrix of 12×10 big square pixels able to emit light in any color, and controllable from a smartphone. A simple demo video will explain the principle better (the LED flicker is due to the video and not normally visible)
A decorative LED frame - [Link]