Hackaday Links: January 25, 2015

Misumi is doing something pretty interesting with their huge catalog of aluminum extrusions, rods, bolts, and nuts. They’re putting up BOMs for 3D printers. If you’ve ever built a printer with instructions you’ve somehow found on the RepRap wiki, you know how much of a pain it is to go through McMaster or Misumi to find the right parts. Right now they have three builds, one with linear guides, one with a linear shaft, and one with V-wheels.

So you’re finally looking at those fancy SLA or powder printers. If you’re printing an objet d’arte like the Stanford bunny or the Utah teapot and don’t want to waste material, you’re obviously going to print a thin shell of material. That thin shell isn’t very strong, so how do you infill it? Spheres, of course. By importing an object into Meshmixer, you can build a 3D honeycomb inside a printed object. Just be sure to put a hole in the bottom to let the extra resin or powder out.

Remember that episode of The Simpsons where Homer invented an automatic hammer? It’s been reinvented using a custom aluminum linkage, a freaking huge battery, and a solenoid. Next up is the makeup shotgun, and a reclining toilet.

[Jan] built a digitally controlled analog synth. We’ve seen a few of his FM synths VA synths built from an LPC-810 ARM chip before, but this is the first one that could reasonably be called an analog synth. He’s using a digital filter based on the Cypress PSoC-4.

The hip thing to do with 3D printers is low-poly Pokemon. I don’t know how it started, it’s just what the kids are doing these days. Those of us who were around for Gen 1 the first time it was released should notice a huge oversight by the entire 3D printing and Pokemon communities when it comes to low-poly Pokemon. I have corrected this oversight. I’ll work on a pure OpenSCAD model (thus ‘made completely out of programming code’) when I’m sufficiently bored.

*cough**bullshit* A camera that can see through walls *cough**bullshit* Seriously, what do you make of this?

A 16-voice Homebrew Polyphonic Synth

Homebrew synths – generating a waveform in a microcontroller, adding a MIDI interface, and sending everything out to a speaker – are great projects that will teach you a ton about how much you can do with a tiny, low power uC. [Mark] created what is probably the most powerful homebrew synth we’ve seen, all while using a relatively low-power microcontroller.

The hardware for this project is an LPC1311 ARM Cortex M3 running at 72 MHz. Turning digital audio into something a speaker can understand is handled by a Wolfson WM8762, a stereo 24-bit DAC. Both of these chips can be bought for under one pound in quantity one, something you can’t say about the chips used in olde-tyme synths.

The front panel, shown below, uses 22 pots and two switches to control the waveform, ADSR, filter, volume, and pan. To save pins on the microcontroller, [Mark] used a few analog multiplexers. As far as circuitry goes, it’s a fairly simple setup, with the only truly weird component being the optocoupler for the MIDI input.

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The software for the synth is written mostly in assembly. In a previous version where most of the code was written in C, everything was a factor of two slower. Doing all the voice generation in assembly allowed for twice as many simultaneous voices.

It’s a great project, and compared to some of the other synth builds we’ve seen before, [Mark]’s project is at the top of its class. A quick search of the archives says this is probably the most polyphonic homebrew synth we’ve seen, and listening to the sound sample on the project page, it sounds pretty good, to boot.

Cloning a Board from Pictures on the Internet

[Andrew] was a pretty cool guy in the early 90s with an awesome keyboard synth that did wavetable synthesis, sampling, a sequencer, and an effects processor. This was a strange era for storage; a reasonable amount of Flash memory was unheard of, and floppy disks ruled the land. [Andrew]’s synth, though, had the option to connect SCSI drives. Like all optional add ons for high-end equipment, the current price for the Ensoniq SCSI card is astronomical and [Andrew] figured he could build one of these cards himself.

Poking around eBay, [Andrew] found the card in question – just a few passives, some connectors, a voltage regulator, and an odd chip from AMD. This chip was a 33C93A, a SCSI controller, and a trip down the Chinese vendor rabbit hole netted him one for $7. Can’t do better than that.

With the datasheet for the chip in hand and a few reasonable assumptions on how the circuit worked, [Andrew] tried to figure draw the schematic. After doing that, he found another hobbyist that had attempted the same project a few years earlier. All the nets were identical, and all that was left to do was sending a board off to the fab.

A quick trip to Front Panel Express got [Andrew] a mounting bracket for the card, and after plugging it in to the synth revealed a new option – SCSI. It worked, and with an ancient SCSI CD-ROM drive, he had boatloads of offline storage for his synth. Great work, and something we’d love to see more of.

 

Hacking VGA for Trippy Video Effects

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Ever since flat panel LCD monitors came on the scene, most old CRTs have found their ways into the garbage or into the backs of closets. For this project, it might be a good idea to pull out the old monitor or TV out and dust it off! [James] has found a way to hack the VGA input to these devices to get them to display vivid visualizations based on an audio input.

The legacy hardware-based project is called RGB.VGA.VOLT and works by taking an audio signal as an input, crossing some wires, and sending the signal through a synthesizer. The circuit then creates a high-frequency waveform that works especially well for being displayed on VGA. The video can also be channeled back through an audio waveform generator to create a unique sound to go along with the brilliant colors.

[James]’s goals with this project are to generate an aesthetic feeling with his form of art and to encourage others to build upon his work. To that end, he has released the project under an open license, and the project is thoroughly documented on his project site.

There have been plenty of hacks in the past that have implemented other protocols with VGA or implemented VGA on microcontrollers, but none that have hacked the interface entirely to create something that looks like the Star Gate sequence from 2001: A Space Odyssey. We think it’s a great piece of modern art and a novel use of VGA!

Thanks for the tip, [Kyle]!

PS/2 Synth Will Knock You Off Your Broom

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Here’s a hack centered around something a lot of people have sitting around: a PS/2 keyboard. [serdef] turned a Harry Potter-edition PS/2 into a combination synth keyboard and drum machine and has a nice write-up about it on Hackaday.io.

For communication, he tore up a PS/2 to USB cable to get a female mini DIN connector and wired it to the Nano. He’s using a Dreamblaster S1 synth module to generate sounds, and that sits on a synth shield along with the Nano. The synth can be powered from either the USB or a 9-volt.

Keymapping is done with the Teensy PS/2 keyboard library. [serdef] reused a bunch of code from his bicycle drummer project which also employed the Dreamblaster S1. [serdef] is continually adding features to this project, like a pot for resonance control which lets him shape the waveform like an analog synth. He has posted some handy PS/2 integration code, his synth code, and a KiCad schematic. Demo videos are waiting for you across the link.  Continue reading “PS/2 Synth Will Knock You Off Your Broom”

Commodore 64 and Nintendo Make Beautiful Music Together with SYNCART

Cyncart

[Dan] has been hard at work developing CYNCART to get his Commodore 64 and original NES to play together. We’ve seen [Dan’s] handiwork before, and it’s pretty clear that he is serious about his chip tunes.

This project starts with something called a Cynthcart. The Cynthcart is a Commodore 64 cartridge that allows you to control the computer’s SID chip directly. In effect, it turns your Commodore 64 into a synthesizer. [Dan] realized that the Commodore’s user port sends out simple eight bit values, which happens to match perfectly with the NES’ controller ports. In theory, he should be able to get these two systems communicating with each other.

[Dan] first modified the Cynthcart to send data out of the user port on the Commodore. This data gets sent directly to the NES’ 4021 shift register chip in the second player controller port. The NES runs a program to turn this data into sound on the NES’ audio chip. The first player controller can then be used to modify some other sound settings on the NES. Musical notes are played on the Commodore’s keyboard. This setup can also be used to play music on both systems at the same time. Be sure to watch the video of the system in action below.

Continue reading “Commodore 64 and Nintendo Make Beautiful Music Together with SYNCART”

Hackaday Links: April 27, 2014

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The HackFFM hackerspace in Frankfurt finally got their CO2 laser up and running, and the folks there were looking for something to engrave. They realized the labels on IC packages are commonly laser engraved, so they made a DIP-sized Arduino. The pins are labelled just as they would be on an Arduino, and a few SMD components dead bugged onto the pins provide all the required circuitry. Video here.

A few years ago, we heard [David Mellis] built a DIY cell phone for an MIT Media Lab thingy. Apparently it’s making the blog rounds again thanks to the Raspi cell phone we featured yesterday. Here’s the Arduino cell phone again. Honestly we’d prefer the minimalist DIY Nokia inspired version.

The Raspberry Pi is now a form factor, with the HummingBoard, a Freescale i.MX6-powered clone, being released soon. There’s another form factor compatible platform out there, the Banana Pi, and you can actually buy it now. It’s an ARM A20 dual core running at 1GHz, Gig of RAM, and Gigabit Ethernet for about $60. That SATA port is really, really cool, too.

[Richard] has been working on a solar-powered sun jar this winter and now he’s done. The design uses two small solar panels to charge up two 500F (!) supercapacitors. There’s a very cool and very small supercap charging circuit in there, and unless this thing is placed in a very dark closet, it’ll probably keep running forever. Or until something breaks.

Here’s something awesome for the synth heads out there: it’s an analog modeling synthesizer currently on Indiegogo. Three DCOs, 18dB lowpass filter, 2 envelopes and an LFO, for all that classic Moog, Oberheim, and Roland goodness. It’s also pretty cheap at $120 USD. We really don’t get enough synth and musical builds here at Hackaday, so if you’re working on something, send it in.

A glass-based PCB? Sure. Here’s [Masataka Joei] put gold and silver on a piece of glass, masked off a few decorative shapes, and sandblasted the excess electrum away. [Masataka] is using it for jewelery, but the mind races once you realize you could solder stuff to it.