Transmitting MIDI Signals With XBEE

What do you do when you want to rock out on your keytar without the constraints of cables and wires? You make your own wireless keytar of course! In order to get the job done, [kr1st0f] built a logic translator circuit. This allows him to transmit MIDI signals directly from a MIDI keyboard to a remote system using XBEE.

[kr1st0f] started with a MIDI keyboard that had the old style MIDI interface with a 5 pin DIN connector. Many new keyboards only have a USB interface, and that would have complicated things. The main circuit uses an optoisolator and a logic converter to get the job done. The MIDI signals are converted from the standard 5V logic to 3.3V in order to work with the XBEE.

The XBEE itself also needed to be configured in order for this circuit to work properly. MIDI signals operate at a rate of 31,250 bits per second. The XBEE, on the other hand, works by default at 9,600 bps. [kr1st0f] first had to reconfigure the XBEE to run at the MIDI bit rate. He did this by connecting to the XBEE over a Serial interface and using a series of AT commands. He also had to configure proper ID numbers into the XBEE modules. When all is said and done, his new transmitter circuit can transmit the MIDI signals wirelessly to a receiver circuit which is hooked up to a computer.

PVC Percussion Pipe Organ Sounds Surprisingly Good!

PVC Instrument

Using over 20′ feet of PVC pipe, a whole bunch of 2 x 4’s and a few nuts and bolts, [Jeremy] and his cousin put together a rather unique percussion pipe organ.

[Jackson], his cousin who is a musician is always looking for different ways to make music. They had a rough idea of what they wanted to do with a few sketches, but after a day of tinkering, they ended up with something completely different — but it sounds awesome.

The frame is made of a combination of 2 x 6’s and 2 x 4’s which hold the PVC tubes in place. PVC elbows and varying lengths of pipe create a wide range of rather deep bass notes. It can be played with just your hands, or even a pair of sandals for better effect. You’d be surprised how good it sounds.

Continue reading “PVC Percussion Pipe Organ Sounds Surprisingly Good!”

A Guitar From An Old Tin Box

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[Atdiy and Whisker], collectively known as  [The Tymkrs] have been busy honing their luthier skills. They’ve created a 10 part YouTube series about the construction of their new cigar box guitar. Instead of a cigar box though, they’ve substituted a 1920’s tin cigarette box. The Omar Cigarette company gave “Project Omar” it’s name. Like [Tymkrs] previous guitar, Omar is a three string affair. The neck was cut from Black Palm, which really shined when polished with a mixture of orange oil and beeswax. They also threw in a couple of new tricks on this build. Omar is an electric guitar, with a pickup custom wound  by [Bob Harrison]. Omar also has frets, which creates a whole new set of complications. Frets are generally installed by cutting slits in the guitar neck with a fret saw. Rather than buy a new tool, [Tymkrs] created a simple jig for their mini table saw. The jig held the guitar neck perpendicular with the saw blade. This made quick work of the many fret slits to be cut. Installed frets must also be dressed and leveled, which is a time-consuming process. 

The tin cigarette box also created a new set of problems. The thin tin proved to be a bit on the weak side when the strings were tightened down. A bit too much pressure on the box while playing would cause notes to bend, much like the tremolo or whammy bar on a standard electric guitar. [Tymkrs] were able to counteract this by adding bracing inside, and a couple of black palm braces to the back of the box.

Hum was also a problem. When [Tymkrs] first plugged in, they found they had more 60Hz mains hum than signal from their strings. Omar uses a classic single coil guitar pickup. Single coils will pick up noise from any magnetic field, including the field created by the studio electrical system. A humbucking pickup uses two coils to counteract this effect. Humbuckers also have a slightly different tone than single coils. [Tymkrs] wanted to stick with their single coil tone, so they counteracted the hum by raising the pickup closer to the strings. Higher pickups receive more signal from the strings, so this is basically a free signal to noise ratio improvement. They also grounded the entire tin box, along with Omar’s metal tail stock. The final build sounds great, as evidenced by the jam session toward the end of Video 10.

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Making A Propane Tank Hank Drum

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A [Hank Drum], as explained here, is a steel drum-type instrument made out of a propane tank. The name comes from the [Hang] or [Hang Drum] which is significantly more expensive than that $40 or so an empty propane tank costs. Of course, you’ll have to do some work to get it to play beautiful music, which can be seen in a time-lapse construction video after the break.

The details of how this instrument was made can be found here, including how to lay everything out and cut out eight relatively neat “tongues” for producing different tones. I used a Dremel tool, but this can also be done using saber saw for a curved top. This method is explained here with a template, but the results may not be as neat.

If you want to try this yourself, make sure to use an empty, unused propane tank. This is extremely important. For another entirely different homemade instrument, why not check out the [Whamola] that we made a year or so ago? Continue reading “Making A Propane Tank Hank Drum”

Hackaday Links: December 13th, 2012

Cardboard box computer

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[Alistair] chapman had a Laptop with a broken screen sitting in his parts bin. He knew he had an LCD panel on hand that would probably work with it, but it wouldn’t fit in the case. His solution was to transplant all the computer parts into a cardboard box from a motherboard.

This violin is garbage

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The kids in this orchestra live in a villiage built on top of a landfill. But they make the most out of what they have. This orchestra is composed of instruments built from garbage and they seem to work pretty well. [Thanks Bruce]

More LED mystery puzzles

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[Henryk] is at it again. He puts together some very impressive circuits that play tricks on your engineering mind. His latest is three LEDs in series. Look closely and you’ll see they’re not performing as expected. Watching the solution to one of his previous puzzles will help you figure out how he’s doing it. His work is simply amazing.

Netbook framed as a dedicated weather station

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Not wanting to get rid of old but still working hardware, [Retro Toaster] built a dedicated weather station by mounting the screen, keyboard, and track pad in a picture frame.

Current and voltage testing your USB projects

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This dev board is a pass-through for USB devices. It makes voltage and current testing your device quite simple.

How To Make A Whamola

whamola stringing and playing

If you’ve ever wanted to combine the extreme note-bending capability of a trombone with the obvious awesomeness of a bass guitar, maybe a whamola like this one could be for you!  I’d never heard of one until recently, and haven’t picked up my bass in years, but my much more musically inclined cousin and I decided to build one.

It should be noted that this instrument is quite prone to string breakage if the handle is used too forcefully, so caution should be used both when building and playing.  As with many hacks an old piece of equipment, a bass guitar in this case, was partially sacrificed to make it.

The build itself, outlined here for the main assembly, or this post for mounting the electronics, was quite simple.  It took an afternoon of milling machine and miter saw work to get the 1 3/8 inch square piece of wood cut to size.  Cavities for the electronics and a slot for the handle axis (components for a screen repair tool and a bolt) were cut with the milling machine – a router could also be used.  It turned out to be a ton of fun to play, especially with an amp and distortion pedal.  Check out the video after the break to see us playing it, as well as one of the whamola going together! Continue reading “How To Make A Whamola”