Hackaday.io contributor extraordinaire [al1] has been playing around with small LEDs a lot lately, which inevitably leads to playing around with large groups of small LEDs. Matrixes of tiny RGB LEDs, to be precise.
First, he took 128 0404 SMD RGB LEDs (yes, 40 thousandths of an inch on each side) and crammed them onto a board that’s just under 37 mm x 24 mm. He calls the project 384:LED (after all, each of those 128 packages has three diodes inside). A microcontroller and the driver chips are located on a separate driver board, which piggy-backs via pin headers to the LED board. Of course, he had to use 0.05 inch headers, because this thing is really small.
Of course, no project is without its hitches. [al1] bought LEDs with the wrong footprint by mistake, so he had a bunch of (subtly different) 0404 LEDs left over. Time for an 8×8 matrix! 192:LED isn’t just the first project cut in half, though. It’s a complete re-design with a four-layer board and the microcontroller on the back-side. And as befits a scrounge project with lots of extreme soldering, he even pulled the microcontroller off of a cheap digital FM radio. Kudos!
We’re in awe of [al1]’s tiny, tiny hacking skills. Now it’s time to get some equally cool graphics up on those little displays.
[wattnotions] has been playing with matches, well the box they come in anyway. One day he was letting synapses fire unsupervised, and wondered if he could build a robot inside of a matchbox. His first prototype was a coin lithium battery and scrounged motors from those 3 US Dollar servos you can buy by the dozen. It scooted around just fine, but it drained the battery instantly and was a little boring.
Next, he etched a board. It had a little PIC micro, a connector for a mini LiPo, and an H bridge. It fired up just fine, and even though it drained the battery way too fast, at least it wasn’t brainless anymore. In our experience, robots tend to discard all the useful data they collect anyway, so being blind wasn’t too much of a problem.
Inspired and encouraged, with synapses gloriously undeterred, [wattnotions] set out to make a version 2. This time he ordered a board from OSHPark, made a 3D model in SketchUp, and proceeded to lock himself out from his own chip. Without a high voltage programmerhe was out of luck. The development was unfortunately put on hold.
It was fun to read along with [wattnotions] as he went on a small robot adventure. We hope he’ll complete a version 3 and have a swarm of the little fellows scooting around.
If your next project needs the ability to play MP3s but you don’t have a lot of room to spare in your enclosure, [Boris] has just the thing you need. His tiny embedded MP3 module supports playback of up to 65,536 songs or as many as you can fit on a 16GB microSD card, which isn’t bad in the least.
The module relies on a PIC24F for input and control, while a VS1011 handles all of the MP3 decoding responsibilities. He says that the module would be great for voice-enabled vending machines, telephone systems, cars, and more.
With such a wide range of possible applications, he decided that the module should be able to support several different input methods. The board can be controlled via a set of digital input buttons, which is perfect for direct human interaction, while it also supports serial control for scenarios where it is part of a larger embedded system.
Of course, we’ve seen tiny MP3 players like this before, but we like the fact that this module was designed to operate in standalone mode or as a component in a larger device. Of course all of the device’s schematics, code, and a BoM are available, allowing you to build your own if you are comfortable with SMD soldering.
[Fabio Varesano’s] new Arduino compatible board packs a full power punch in a ultra compact layout, measuring at 20.7×15.2 mm, the Femtoduino is probably the smallest 328 based Arduino compatible board around. Most of the staples are present, an QFN atmega328, an MIC5205 low dropout regulator good for a couple hundred milli amps, 16MHz ceramic resonator, reset, power indicator and pin 13 LEDs, but you will need to provide your own serial connection (FTDI, MAX232 etc) and another AVR programmer to get the Arduino boot loader onto the chip.
Since the board is small (smaller than a pro mini) it is not directly breadboard friendly. Even though the hole spacing is 0.05 inch, the size is large enough for “normal” wire to fit into fine, if you wish to use 0.1 inch spacing there is a handy break out board you can make where the Femtoduino just snaps in.
Everything needed to make one of your own is provided on the website, schematics, kicad files, bill of materials, Gerbers for both the board and the breakout board, though we would like to see this as a pre-made board soon, join us after the break for a video and see why.
This tiny bot wants to go inside your body. That’s right, it was designed to travel through veins. The little bot has no on board propulsion system. It is controlled by a magnet outside the body. See those little spines? Those straighten out to keep the bot in place when it isn’t supposed to move. Creepy right? In all the articles we’ve seen on this bot, there aren’t any details about what actually is on board. They mention adding a camera in the near future, but why are they calling it a robot? Surely there’s something cool in that little body. This is a quite practical application of a project we covered recently. Commenters weren’t impressed with the external control system, likening it to the old vibrating football player game. Well, here’s where it could be usefull.