This schematic is all you need to build your own voltage converter. [Lutz] needed a converter that could boost 5 V to 30 V to power a string of LEDs. The solution was to use low cost ATtiny85 and some passive components to implement a boost converter.
This circuit follows the classic boost converter topology, using the ATtiny85 to control the switch. The 10 ohm resistor is fed back into the microcontroller’s ADC input, allowing it to sense the output voltage. By measuring the output voltage and adjusting the duty cycle accordingly, the circuit can regulate to a specified voltage setpoint.
A potentiometer is used to change the brightness of the LEDs. The software reads the potentiometer’s output voltage and adjusts the voltage output of the circuit accordingly. Higher voltages result in brighter LEDs.
Of course, there’s many other ways to implement a boost converter. Most practical designs will use a chip designed for this specific purpose. However, if you’re interested in rolling your own, the source and LTSpice simulation files are available.
Last year, [Ytai] went to Burning Man for the first time. He was a bit inexperienced, and lacked the lumens to make him visible on the Playa. This year, he made up for it by building an extra bright LED Jacket.
The jacket consists of 48 LEDs, at 150 lumens each. Each RGB LED module was placed on its own PCB, and controlled by the tiny PIC12F1571 microcontroller. This microcontroller was a great fit since it has three PWM channels (one for each color) and costs 50 cents. Firmware on the PIC allows the boards to be daisy-chained together to reduce wiring. This was done by using a protocol similar to the popular WS2811 LEDs.
Assembling 50 of the boards presented a challenge. This was addressed by using surface mount components, a solder stencil from OSH Stencils, an electric skillet, and a good amount of patience. The final cost of each module was about $3.
With 50 of the boards assembled, a two layer jacket was sewn up. The electronics were sandwiched between these two fabric layers, which gave the jacket a clean look. A wrist mounted controller allows the wearer to select different patterns.
For a full rundown of the jacket, check out the video after the break.
Continue reading “A Very Bright LED Jacket”
Burning man, the premier desert-based convention, is a vacation for some. [Sam], on the other hand, points out that he is there to get his hands dirty. This year, he (with a team of six) built a set of 20 interactive lotus flowers that light up in sync with a heartbeat.
[Sam]’s biofeedback circuit is able to sense up to two heartbeats per flower. When a person’s heartbeat is detected, a set of high-power LEDs light up from the base of the stem upwards towards the petals for an incredible illuminated display of biofeedback.
The lotus flowers themselves aren’t anything to scoff at, either. They range from 8 to 18 feet high and are made out of steel and rowlux plastic. The circuit boards are all custom-made as well, with every part chosen to be as affordable as possible. The whole installation is powered by a deep-cycle marine battery and a set of 6V batteries, which can run all of the electronics in the flowers for the entire night before needing a recharge.
Burning man is a great example of art meeting technology. For other examples, check out this 2010 pyrotechnic ball, or head there yourself next August! Be sure to check out the videos and the project’s code on the project site as well.
LED’s are fun. They are easily seen, not to hard to hook up, and produce a nice glow that can be gazed at for hours. Kids love them, so when [Jens] daughter was born, he knew that he wanted to create a device that would alternate colors depending on the object’s movement.
He utilized a mpu6050 accelerometer to detect changes in position, and wired together an Arduino Nano, a 9V battery, and a 12 LED neopixel ring from adafruit. Design requirements were jotted down beforehand ensuring that any child playing with the Hypno-Jellyfish would not be injured in any way. For example, anything that fits in a child’s mouth, will go in that child’s mouth; meaning that any materials used must be non-toxic, big enough not to be swallowed, and drool proof/water proof. The kids will pull, and throw, and drop the toy as well, so everything has to be of sturdy quality too. Epilepsy is also a concern when dealing with LED’s. But, [Jens] project hit the mark, making something that is kid-friendly while at the same time enjoyable for anyone else who likes color-changing lights.
Continue reading “Hypno-Jellyfish is Great for Kids (and Kids at Heart)”
Love the classic brick Game Boy, but hate the low-contrast LCD, terrible battery life, and the inability to play Pokemon Emerald? This one’s just for you. It’s the ultimate DMG Game Boy – a Game Boy Advance SP stuffed (is it stuffed if it’s taking up more room?) into the classic Game Boy enclosure. Forum thread.
Zooming in to a microchip. It starts off with a DSLR and ends up on a scanning electron microscope. This is an older chip, and the CPU you’re using right now probably has much smaller features.
Every movie and every TV show set in space invariably has space helmets with LEDs pointing towards the face. Think how annoying that would be for an astronaut. Here’s how you add LEDs to a space helmet for a nice theatrical effect. Just don’t use it on a real EVA.
Everyone’s favorite crowdfunded space probe can apparently be detected with an 8-foot dish. That’s the same size as an old C-band dish, a.k.a West Virginia wildflowers. We know some of you have one of these out there, so go make a ~2GHz feed horn, grab a USB TV dongle, write it up, and send it in.
Alright, MAME cabinets. Say you want to go old-school and have a CRT. Some arcade games use a vertically oriented display, while other, slightly more modern games use a horizontally mounted display. How do you fix this? Get a big bearing, of course. This one allows a 19″ CRT to be rotated 90 degrees – all you need, really, if you’re switching between Pacman and Mortal Kombat.
Hey mechanical keyboard enthusiasts! Here’s some Hackaday Cherry MX keycaps. Informal interest check in the comments below. Suggestions welcome.
A new edition of The Hacklet is now available It covers some of our favorite stuff going on in the Hackaday Projects community.
In this edition, we round up a few hacks involving cars. There’s Bluetooth Low Energy connectivity, vehicle telematics, and tools to hack into your car’s CAN bus. If you’ve ever wanted to clear that pesky check engine light without paying the dealer, or unlock your car with a smart watch, these are worth a look.
Next up are a bunch of LED hacks. This starts with a DIY theater light, then looks at a portable DJ booth, finishing off with our Evil Overlords’ own LED visualization platform.
Finally, we check out a new 3D printer design. This one uses polar coordinates instead of the Cartesian coordinate system that most printers use. This gives it the unique ability to print with multiple extruders at the same time.
Once again, let us know what you think of this edition in the comments. Our goal is to keep you entertained with some of the coolest hacks on the site.
[Flyingpuppy] sent us this tip about her cleverly-concealed pull-out lightbox drawer. Her resolution for the new year was to make more art, so she filled this coffee table with art supplies and decided she’d draw while relaxing in front of the television. She also wanted a lightbox nearby, which originally involved hacking the entire tabletop with some acrylic, but she eventually opted for a simpler build: and it’s portable, too! The drawer’s lights are battery-powered, so you can pull the entire thing out of the table and drag it onto your lap, if that makes drawing more comfortable.
[Flyingpuppy] sourced seven inexpensive LED units from her local dollar store, which she mounted to the back of the drawer with some screws. The rest of the drawer was lined with white foam board, the bottom section angled to bounce light up onto the acrylic drawing surface. Because she needs to open the case to manually flip on the lights, she secured the acrylic top magnetically, gluing a magnet to the underside of the foam board and affixing a small piece of steel to the acrylic. A simple tug on the steel bit frees the surface, providing access underneath. Stick around for a video below.
Continue reading “Built-in Coffee Table Lightbox”