Addressable RGB LED Strip

June 17, 2009 by Zach Banks 50 Comments

ledrgb

[Synoptic Labs] stumbled upon an RGB light strip with individually-controllable LEDs. The strip uses 5 volts and is controlled by an HL1606. Because the strips are hard to find, this chip is mostly undocumented and he had trouble driving the strip. He was unable to get it working until he met with [John Cohn], who had previously reverse-engineered the serial protocol. Working together, they released a library for the Arduino to drive the strip. So far, the library only supports fading each LED, the only known functionality. If more strips like these were available, constructing LED matrices would be much easier. Embedded below is a video of the strip fading through the rainbow.

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LED Clock Strips Time Down To Pulses Of Light

April 15, 2020 by Kristina Panos 7 Comments

Nietzsche said (essentially) that time is a flat circle — we are doomed to repeat history whether we remember it or not. This is a stark and sobering thought for sure, but it’s bound to dissipate the longer you look at [andrei.erdei]’s literal realization of time as a flat circle.

A clock that uses nothing but RGB LEDs to give the time sounds confusing and potentially cluttered, but the result here is quite pleasing and serene. We figure it must be the combination of brighter LEDs to represent 12, 3, 6, and 9, and dimmer LEDs for the rest of the numbers, plus the diffusion scheme. The front plate is smoky acrylic topped with two layers of frosted black window foil.

Inside the printed plastic ring are two adhesive RGB LED strips running on an ESP8266 that ultimately connects to an NTP time server. The strips are two halves of an adhesive 60 LED/meter run that have been stuck together back to back so that the lights are staggered for seamless coverage. This sets up the coolest thing about this clock — the second hand, which is represented by a single pink LED zig-zagging back and forth around the ring. Confused? Watch the short demo after the break and you’ll figure it out in no time.

Now that times are strange, you might be more interested in a straightforward approach to finding out what day it is. The wait is over.

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LEDs Strips Tell You The Trains Aren’t Running

May 8, 2015 by Bryan Cockfield 15 Comments

[James] is a frequent user of the London Underground, a subway system that is not immune to breakdowns and delays. He wanted a way to easily tell if any of the trains were being disrupted, and thanks to some LEDs, he now has that information available at a glance without having to check a webpage first.

Inspired by the Blinky Tape project at FT Engineering, [James] thought he could use the same strip of addressable LEDs to display information about the tube. A Raspberry Pi B+ gathers data from the London Underground’s TfL API and does a few calculations on the data. If there is a delay, the LEDs in the corresponding section of the strip will pulse, alerting the user to a problem with just a passing glance.

The project is one of many that displays data about the conditions you’ll find when you step outside the house, without having to look at a computer or smartphone. We recently featured an artistic lamp which displays weather forecasts for 12 hours into the future, and there was an umbrella stand which did the same thing. A lot is possible with LEDs and a good API!

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Graphing The Efficiencies Of LED Light Strips

October 23, 2012 by Brian Benchoff 35 Comments

After adding a few LED light strips above his desk, [Bogdan] was impressed with the results. They’re bright, look awesome, and exude a hacker aesthetic. Wanting to expand his LED strip installation, [Bogdan] decided to see if these inexpensive LED strips were actually less expensive in the long run than regular incandescent bulbs. The results were surprising, and we’ve got to give [Bogdan] a hand for his testing methodology.

[Bogdan]’s test rig consists of a 15 cm piece of the LED strip left over from his previous installation. A Taos TSL2550 ambient light sensor is installed in a light-proof box along with the LED strip, and an AVR microcontroller writes the light level from the sensor and an ADC count (to get the current draw) of the rig every 6 hours.

After 700 hours, [Bogdan]’s testing rig shows some surprising results. The light level has decreased about 12%, meaning the efficiency of his LED strip is decreasing. As for projecting when his LEDs will reach the end of their useful life, [Bogdan] predicts after 2200 hours (about 3 months), the LED strip will have dropped to 70% of their original brightness.

Comparing his LED strip against traditional incandescent bulbs – including the price paid for the LED strip, the cost of powering both the bulb and the strip, the cost of the power supply, and the time involved in changing out a LED strip, [Bogdan] calculates it will take 2800 hours before cheap LEDs are a cost-effective replacement for bulbs. With a useful life 600 hours less than that, [Bogdan] figures replacing your workshop lighting with LED strips – inexpensive though they are – isn’t an efficient way to spend money.

Of course with any study in the efficiency of new technology there are bound to be some conflating factors. We’re thinking [Bogdan] did a pretty good job at gauging the efficiency of LED strips here, but we would like to see some data from some more expensive and hopefully more efficient LED strips.

LED Ambient Light Strips

May 30, 2008 by Will O'Brien 6 Comments

[Shadow] sent in his ambient LED strip project. He picked up a ton of RGB (Red/Green/Blue) LEDs off of eBay and built several LED strips. To get up and running, he used an LED-wiz controller. With the off the shelf controller, this is a pretty easy project, and the ambient lighting effect looks great. Check out the video after the break or on the project page.

In 2006, we posted about [rafkep]’s similar ambient lighting project.

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The BAPPR Keeps Your Addressable LED System Cool

July 27, 2024 by Alexander Rowsell 17 Comments

We all love a nice strip or grid of addressable LEDs. It can add flair or an artistic touch to many projects, and it can make gaming computers look extra 1337. However, providing enough current to a long strip of addressable LEDs can sometimes be difficult. Often a separate voltage rail is needed to supply enough juice. At the same time, continually sending out data to animate them can often use 100% of the microcontroller’s CPU power, especially if the serial bus is being bit-banged. A crash or badly timed interrupt can leave the system in a weird state and sometimes with the LEDs not displaying the correct colours. Or you might just want to enter a power-saving mode from time to time on your main MCU? Well, the BAPPR is designed to address all of these problems.

[TheMariday] created the BAPPR and made it fully open-source. It’s a switch-mode power supply that can accept anywhere from 7 V to 17 V and converts it into a strong 5 V rail for typical addressable LEDs. It also has a “smart” mode where it monitors the data line going to the LEDs to see if there is activity. If for some reason the system stops sending data, the BAPPR can intervene and shut off the power to the LEDs, which can help prevent strange colour combinations from being displayed while the system recovers. Once data starts flowing again, power is restored and the light party can resume.

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Linear LED clock displaying the time using different-colored triangles.

Linear LED Clock Looks Decidedly Vintage

May 24, 2024 by Kristina Panos 3 Comments

We just love a good clock around here, and something about those triangles gives this linear LED clock a deliciously mid-century vibe. If you’ve read these pages for any length of time, you know that [andrei.erdei] loves clocks as much as we do, and is always coming up with interesting ways of displaying the passage of time.

This one is a remix of some other linear RGB clocks, but the result is distinctly [andrei.erdei]’s style. There’s nothing crazy going on under the hood here — it’s essentially a Wemos D1 mini running a strip of RGBs, and the microcontroller connects to a Wi-Fi router to get the time from a server. The magic is in the programming and the way the clock is read.

The brief but thorough demo video after the break does a much better job of explaining the display by showing various times of the day, but we’ll give it a shot. For one thing, it uses 24-hour time exclusively. There are four groups of triangles; yellow, red, green, and blue which correspond to tens and units of hours, and tens and units of minutes.

The triangles light up in groups of three in the order depicted in the animation. At midnight, none of the triangles are lit up. Again, it’s best explained in the video, looking at various times of day. Plus you can see the neat-o startup animation.

Are you more into sound than blinkenlights? Then this customizable bird clock may be for you.

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