A Sound and LED-tastic Tricycle Shopping Cart

What do you get when you take a massive number of LEDs and combine them with a shopping cart and a bicycle? An awesome rave-mobile created by [kramerr]. He’s even taking it one step further by making the electronics solar powered.

[Kramerr] controls the LEDs with multiple WS2803 LED drivers. Three PIC18F4550s control the WS2803s over SPI. He devised a neat way of exciting the LEDs from music by using a pair of graphic equalizer display filter chips, MSGEQ7s, to drive the PICs to create patterns. A USB input also allows the PICs to display song titles or other information.

leds and boards

The mechanical design is as impressive as the electronics. The rear half of a bicycle is welded to the frame of the shopping cart with the cart’s handle used for steering. The shopping cart’s rear wheels are replaced by small bicycle wheels.

But [Kramerr] wasn’t done. He built his own solar panel since he couldn’t find one to fit the size requirements. The panel consists of 26 cells connected in series to provide 1A at 13V on a sunny day. A solar charge controller keeps a standard 12v lead acid battery ready to power the tricycle cart.

And there is still more! There is a sound system driven by a Raspberry Pi. The Pi also drives the USB inputs when [Krameer] wants to display song titles or artists instead of the audio patterns.

There are at least four hacks in this project each worthy of applause. [Karmeer] deserves an ovation for doing all of them in one project. If you are looking for less bling and less pedaling may we direct you to this powered, riding shopping cart.

Some rave music and lights via video after the break.

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THP Entry: Atomic Space Time

LCD featuring HaD logo

Accurate time is all around us. Streaming down from satellites thousands of miles in space, UTC time information is at all of our fingertips. You just have to know how to reach out and grab it. [hkdcsf] not only knows how to do this, he does it in style.

Tipping his hat into The Hackaday Prize contest, [hkdcsf]’s atomic clock is masterfully crafted. Not only does it get time information from GPS satellites, it also has the ability to grab the infomation from the DCF77 transmitter. And if ever it’s in a position where neither signal can be found, an RTC crystal keeps the time and date accurate.

His design is based on a PIC18F25K20, and bristles with so many features that it might make you dizzy. So be warned – you might want to be in a seated position before taking a look at this project. [hkdcsf] does a great job at detailing exactly how his clock works, and his efforts to provide this level of detail will surely help other hackers to add similar features to their future projects.

SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

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A wedding cake made out of LEDs

[Andrew] wanted to do something special for his wedding. Since he and his fiance [Missy] decided on a cupcake wedding cake, [Andrew] decided to wow his guests with an RGB LED cupcake holder.

The tiers of [Andrew] and [Missy]’s cupcake holder are made of acrylic laser etched with a damask pattern. These tiers are supported by a cylinder embedded with RGB leds that provide edge lighting for the acrylic panels. The effect is a series of permutating lights that illuminate the cupcake holder with every imaginable color. On the top of the cupcake cake, there’s a great cake topper made of frosted and laser cut acrylic that has the same color fade effect as the cupcake holder.

On the electrical side of things, the cupcake holder has 44 LEDs on all it’s levels. FETs driven by a 40-pin PIC18F control all the LEDs and the whole piece is powered by a computer power supply.

It’s an awesome build, especially considering it was finished just days before the wedding. After the break, you can check out a few more videos showing off the beauty of [Andrew] and [Missy]’s wedding cake.

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Overbuilding an iTunes rating system

Even though iTunes and it’s song rating system has been around for over a decade now, [Steve] still hasn’t gotten around to assigning ratings to his vast library of MP3s. We can’t blame him – who wants to pull up iTunes every four minutes and assign a star rating to each song individually? To solve this interface problem, [Steve] set out to design a hardware song rating interface that fell down the rabbit hole into development hell.

The build started off simply enough – just an Arduino attached to a few buttons that sends data to a Cocoa app which rates the current song. Everything was working wonderfully until [Steve] restarted his mac and the COM ports went to pot. Wanting a ‘plug-and-play’ solution, he did away with the Arduino-based build and started designing a USB device that would display the current iTunes track and provide hardware buttons for rating the current song.

The current build is based around a very capable PIC 18F4550 micro. After looking up the USB HID protocol, [Steve] had some boards fabricated. He’s keeping us waiting on a final build report, but with the amount of work that went into this project, we’re sure it’ll be a winner.

Dot matrix clock on the way


[Kevin] sent in his almost finished open source dot matrix clock. Sporting a hefty 40 x 16 display powered by a PIC 18F he has complete pixel by pixel control of the graphics. Combined with with a triple buffer he is at least able to output 15fps, with planned 30fps. While this has great potential for a clock, what about going further? Twitter updates, chat messages, weather updates, the current airspeed velocity of an unladen swallow; it will be tough to beat the competition without some more features. Either way, its an awesome project and we can’t wait to see it completed.

AXiS-49 teardown


We touched on harmonic table MIDI controllers when [aris] was building one. [Ken Rushton] has one of C-Thru’s commercial keypads, the AXiS-49, and disassembled the device to show how it works. A PIC18F2450 microcontroller provides the USB interface and is connected to a dsPIC33FJ128GP310 digital signal controller which decodes the keypresses. The membrane buttons are made with two concentric graphite disks that touch gold contacts. The microcontroller measures the time between the two points contacting to determine the button velocity. monome button clones also use circular contact pads, but cannot calculate velocity because they only have one element.

[via Matrixsynth]

Autonomous Cookie Monster


[DJ Sures], who built the autonomous Wall-E, is back with another creation. His new autonomous Cookie Monster is certainly an interesting build. He had the cookie monster plush toy already so the first step was to flay the blue beast and insert a skeleton. He used another robot for that. There are two servos for the wheels plus one for each arm and one for the neck. There’s a distance sensor in the mouth. He built a custom board for the PIC18F4685 microcontroller which is running the same 2D mapping code as his previous bot. Check out the video of it in action below. Continue reading “Autonomous Cookie Monster”