While building my zombie containment unit, I decided I wanted some LED displays or bar graphs to complement the containment status video running on the smaller secondary video monitor. Some other containment units used LED air pressure gauges from eBay. I wanted to achieve a similar look, but I also wanted my gauge to be software controllable so I could change the number of segments lit in response to events in the playback of the two videos. I decided it was time to build my own LED bar graphs.
Around one and a half years ago I’ve designed and built various LED dimmers for both white and RGB LEDs. Then late last year someone approached me asking if I could make an RGB dimmer for him, too. But my designs were really tailored to their specific applications and built with home-made, i.e. milled PCBs which are time-consuming to make. So I decided to make a more universal version based on a proper, etched board which could be built in a small series and used for all kind of applications, both white and RGB. The result is this versatile, programmable 4-channel dimmer.
The design is based on my previous RGB dimmer but with a number of improvements.
Michael wrote an article on controlling a bunch of lamps individually with WS2811 drivers and Arduino:
I simply used the same technology as LED strips to allow communication between lamp modules. LED strips have RGB LEDs with an embedded driver chip which uses PWM (pulse width modulation) to control the duty cycle on the red, green, and blue LEDs. This combined LED/chip is called WS2812 or WS2812B. On older LED strips, the driver chip was not embedded into the LED itself, but was a separate chip called WS2811. These standalone driver chips are somewhat obsolete now which means they are cheap! I got 50 of them on eBay for $5.00. Since these modules use the same technology as LED strips, the same code can be used. Adafruit’s NeoPixel library is a very simple way to control LEDs, so we can control each lamp easily. The lamp is controlled by the “blue” pin on the WS2811 so that is the value to set.
If you want a light-up dance floor for your next wedding or other special event, you can rent one; however, that can be quite expensive. On the other hand, you and your hacker friends can always build one. How hard can that be?
Turns out, very hard. While it may be simple to get one translucent panel to illuminate with LEDs, this 17-square-foot interactive dance floor used 64 panels with four lighting cells in each, for a total of 256 lighting arrays and 7,680 RGBs arranged as 2,560 addressable pixels.
Even with some advanced tools like a pick-and-place machine for PCB manufacturing, as well as a laser cutter, it still took volunteers many hours over the course of 11 months to get it working. LED control is accomplished via a Teensy 3.1, while 256 pressure switches under the surface are read by an Arduino Mega.
You can see more details of the impressive project in the video below (including a round of multi-player Dance Dance Revolution) and a few more technical details in AvBrand’s write-up here.
In his quest to create “the coolest wall-mounted bottle opener in the entire world,” it would appear that YouTuber “Never Stop Seeking” has succeeded.
As seen below, the infinity mirror-style unit is made of plexiglass and two-way mirror film, and equipped with Arduino Uno-controlled RGB LED strips that are activated by a proximity sensor as you open a beer or soda. He even included a magnetic catch for his bottle caps!
Want to build one of your own? Good news, Never Stop Seeking plans on sharing more details along with a how-to video in the coming days.
After he’d just finished a project using RGB LEDs, Imgur user nolobot’s brother mentioned he needed a new computer desk. Most people would probably just let their brother buy one, others would make something out of wood, but nolobot instead decided to create something truly amazing using more than 1,200 WS2812 RGB LED modules, an Arduino Mega, aluminum extrusion, and translucent polycarbonate.
The Mega controls these LEDs with the FastLED library, which are sandwiched between a base piece of plywood and a strip of polycarbonate using custom spacers. This diffuses the light nicely, allowing for beautiful light animations directly on the desk’s surface.