Observe A Satellite’s Morse Code Message Today!

December 12, 2012 by Mike Szczys 58 Comments

Niwaka1-satellite

If you live in the Eastern portion of the United States and the skies are clear you can see a student built satellite flashing LEDs in Morse Code today. But don’t worry. If you it’s cloudy or if you live elsewhere there are several other opportunities to see it in the coming days.

This is the Niwaka Fitsat-1. It was developed by students at the [Fukuoka Institute of Technology] and deployed from the International Space Station on October 4th. Included in the payload is an array of LEDs seen in the image above. On a set schedule these are used to flash a Morse Code message for two minutes at a time. That is what’s shown in the image on the upper right.

You can look up information on seeing Fitsat-1 in your own area using this webpage. All of the observation windows in our area require a pair of binoculars or better. We’re not sure if there is any case in which this can be seen by the naked eye.

[Thanks SWHarden and KomradBob]

Driving A WS2811 RGB LED Pixel

December 7, 2012 by Mike Szczys 46 Comments

[Alan] has been working on driving this WS2811 LED module with an AVR microcontroller. It may look like a standard six-pin RGB LED but it actually contains both an LED module and a microcontroller to drive it. This makes it a very intriguing part. It’s not entirely simple to send commands to the module as the timing must be very precise. But once the communication has happened, the LED will remain the same color and intensity until you tell it otherwise. You can buy them attached to flexible strips, which can be cut down to as few as one module per segment. The one thing we haven’t figure out from our short look at the hardware is how each pixel is addressed. We think the color value cascades down the data line as new values are introduced, but we could be wrong. Feel free to discuss that in the comments.

The project focuses on whether or not it’s even possible to drive one of these pixels with a 16MHz AVR chip. They use single-wire communications at 800 kHz and this really puts a lot of demand on the microcontroller. He does manage to pull it off, but it requires careful crafting in assembly to achieve his timing constraints. You can see a quick clip of the LEDs fading between colors after the break.

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Clock Display Taller Than You Is Just What Your Living Room Has Been Missing

December 4, 2012 by Mike Szczys 6 Comments

Sure, it’s time to get the countdown clocks ready to ring in the new year, but why limit it to just one night? If you end up building a six-foot digital display you can count down trivial events; like the remaining seconds of freedom before you have to pimp yourself out in that drab cubicle.

This seven-segment display is homemade and boasts six full-sized digits and two smaller digits with each pair separated by colons. You have probably already guessed that the construction was greatly simplified by using LED strips rather than individual components. This is part of the reason for the size of the display. The strips can be cut, but only down to a minimum of 3 LEDs per segment. That explains the small digits, with their larger siblings doubled in size. But there is a benefit to this constraint, it means that current limiting is already taken care of for you.

The main assembly is a wooden frame surrounding two polycarbonate sheets. The LED strips are sandwiched between those sheets, with segment and digit driver buses exiting a one point on the side. The build doesn’t detail a driver for the display but it shouldn’t be hard to find a multiplexing example that will serve the purpose.

Syncing Two Strands Of G35 Christmas Lights

December 4, 2012 by Brian Benchoff 6 Comments

Lights

For a few years now, the set of Christmas lights most wanted by hackers and makers the world over is the GE G35 color changing set. With 50 individual RGB LEDs controlled by a microcontroller, these light strings can display any pattern of lights with the help of something as simple as an Arduino. The stock light sequences are a little problematic, especially if you’re running more than one string.

[Todd] picked up two G35 strings, and even when they’re turned on at the same time the light sequences slowly go out of sync after a half hour or so. He came up with a great way to make sure these lights stay in sync that requires only a slight modification. To make two light strings stay in sync, it’s simply a matter of disconnecting the data line from one string’s controllers and bridging that connection with the other string.

It’s a very easy modification, but it won’t give you twice as many individually controllable LEDs – for that, you’ll have to use either multiple Arduinos or buy a longer RGB LED strip. Still, having two identical 7×7 LED panels is better than a single panel, so we’ll have to tip our hat to [Todd] for this one.

MonoPong: A CMOS 1-D Pong

November 23, 2012 by Eric Evenchick 6 Comments

We’ve seen a few 1-D pong games recently, and they’ve all be controlled using microcontrollers. Inspired by some of these hacks, [mischka] built the monoPong using a handful of logic chips.

The monoPong has four major components. A 555 timer in astable mode provides a clock source which is fed into a 4510 decade counter, which connects to a 4028 BCD to decimal decoder to drive the LEDs. Finally, a 4011 NAND gate IC is used to deal with the button presses. Two of the NAND gates form a RS flip-flop, and the other two NAND each player’s button with the last LED on the player’s side of the strip. If the player hits the button when their LED is on, the RS flip-flop toggles and changes the decade counter from count up to count down mode. This makes the ball bounce back.

[mischka] finished the project off by putting it in a wooden box and drilling holes for the LEDs, buttons, and a power switch. The final product looks pretty good, and is a great example of how you can use a couple logic chips instead of a microcontroller.

After the break, watch a quick game of monoPong.

Continue reading “MonoPong: A CMOS 1-D Pong” →

8x8x8 LED Cube And The Board That Drives It

November 22, 2012 by Mike Szczys 14 Comments

Check out the LED cube which [Thomas], [Max], and [Felix] put together. But don’t forget to look at that beautiful PCB which drives it… nice! But hardware is only part of what goes into a project like this one. After the soldering iron had cooled they kept going and wrote their own software to generate patterns for the three-dimensional display.

Looking at a clean build like this one doesn’t drive home the amount of connections one has to make to get everything running. To appreciate it you should take a look at this other 512 LED cube which has its wires showing. You can see from the schematic (available in the project repository) that all of these lines are managed by a series of shift registers. The board itself connects to a computer from which it gets the visualization commands. A Java program they call CubeControl can push letters or turn the cube into a VU meter.

The team built at least two of these. This smaller version uses red LEDs, while the larger one shown in the video after the break has blue ones.

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One Dimensional PONG, Take Two

November 18, 2012 by Brian Benchoff 22 Comments

Needing a Christmas present for his 4- and 5-year-old nieces, [John] built a one-dimensional PONG game, sure to be the delight of rosy-cheeked children on a Christmas morn.

The new and improved 1D PONG game is built around a digital RGB LED strip with an LPD8806 LED controller. The speed of the ‘ball’ is controlled by a pot on one side of the game. With each player pressing their button at the right time, the ball bounces back to the other player. Missing the ball awards a point to the other team and most likely an increase in the player’s frustration, greatly increasing the risk of this game being thrown across the room.

While it’s not an obscenely long 1D PONG game like [Jason]’s previous 5 meter version, it’s more than enough to keep a pair of kids occupied for more than a few minutes, a remarkable achievement for just a microcontroller, buttons, and a piece of LED strip.

You can get [John]’s AVR code in this pastebin or just check out the video after the break.

Continue reading “One Dimensional PONG, Take Two” →