If we had a dime for every 555-based noisemaker circuit we see… But this one’s got a twist.
[Tristan] does two things that elevate his sawtooth-wave noisemaker above the norm. First, he gets a clean sawtooth wave out of it so that it sounds about right. Then he manages to make it more or less playable. It’s a refined version of a classic hack.
The first trick is a matter of putting a constant current supply upstream of the timing capacitor. The usual 555-timer circuit just charges the capacitor up from the power rails through a resistor. This is fine if all you care about is timing. But because the current is proportional to the constantly dropping voltage difference, the voltage on the capacitor is an exponential function over time.
We’ve always wanted to implement LED-to-LDR control while writing the Logic Noise series, but never found a reliable way to make it work. It’s cool to see [Tristan]’s efforts. Maybe we’ll pull a 555 out of the junk box in his honor.
For electronics aficionados, there are few devices cooler than music synthesizers. The first synths were baroque confabulations of opamps and ladder filters. In the 70s and 80s, synths began their inexorable march toward digitization. There were wavetable synths that stored samples on 27-series EPROMs. Synths on a chip, like the MOS 6581 “SID chip”, are still venerated today. For his Hackaday Prize entry, [Tim] is building his own synthesizer from scratch. It isn’t a copy of an old synth, instead it’s a completely modern synthesizer with a classic sound.
[Tim] is a former game developer and has already released a synthesizer of sorts. Rhythm Core Alpha 2 for the Nintendo DSi and 3DS is a fully functional synthesizer, but the limitations of the Nintendo hardware made [Tim] want to build his own synth from scratch.
The specs for the synth are more of a wish list, but already [Tim] has a few design features nailed down. This is a virtual analog synth, where everything is digital and handled by DSP algorithms. It’s polyphonic and MIDI capable, with buttons and dials for almost every parameter. For the few things you can’t do with a knob, [Tim] is including a touch screen display.
[Tim] already has the synthesis model working, and from the videos he’s put together, the whole thing sounds pretty good. The next step is turning a bunch of wires, breadboards, and components into something that looks like an instrument. We can’t wait to see how this one turns out!
You can check out a few of [Tim]’s synth videos below.
Not content with fitting a tiny square-wave MIDI synthesizer into a MIDI plug, [Mitxela] went on to cram a similar noisemaker into a USB plug itself.
Besides being physically small, the code is small too, as well as the budget. It uses V-USB for the USB library running on an ATtiny85, and a couple of passive parts. His firmware (apparently) takes in MIDI notes and spits out square waves. Continue reading “Smallest MIDI Synth, Again!”→
Recently I’ve been learning more about classic analog music synthesizers and sequencers. This has led me to the Baby10, a classic and simple analog sequencer design. In this article I’ll introduce its basic operation, and the builds of some awesome hackers based on this design.
Sequencers produce, a sequence of varying voltages. These control voltages (CV) can then be use to control other components. Often this is a simple tone generator. While the concept is simple, it can produce awesome results:
A basic sequencer is a great beginners project. It’s easy to understand the basic operation of the circuit and produces a satisfyingly entertaining result. The Baby 10 was originally published in a column called “Captain’s Analog”, but has now been widely shared online.
The circuit uses the 4017, a simple CMOS decade counter. The 4017 takes an input clock signal then sequentially outputs a high pulse on each of 10 output pins. As such, the 4017 does almost everything we need from a sequencer in a single IC! However, we want our sequencer to output a varying voltage which we can then use to generate differing tones.
To accomplish this variable resistors are connected to each of the output pins. A diode in series with the variable resistor stops the outputs fighting against each other (in layman’s terms).
To make the sequencer more visually attractive (and give some feedback) LEDs are often also added to the output of the 4017. A complete Baby 10 sequencer is shown in the schematic below. The original circuit used 1N917s, these are no longer available but the part has been replaced by the 1N4148.
California textiles artist and musician [push_reset] challenged herself to make a wearable, gesture-based synth without using flex-sensing resistors. In the end, she designed almost every bit of it from the ground up using conductive fabric, resistive paint, and 3-D printed parts.
A couple of fingers do double duty in this glove. Each of the four fingertips have a sensor made from polyurethane, conductive paint, and conductive fabric that is connected to wires using small rivets. These sensors trigger different samples on an Edison that are generated with Timbre.js. The index and middle fingers also have knuckle actuators made from 3-D printed pin-and-slot mechanisms that turn trimmer pots. Bending one knuckle changes the delay timing while the other manipulates a triangle wave.
On the back of the glove are two sensors made from conductive fabric. Touching one up and down the length will alter the reverb. Sliding up and down the other alters the frequency of a sine wave. [push_reset] has kindly provided everything necessary to re-create this build from the glove pattern to the STL files for the knuckle actuators. Check out a short demonstration of the glove after the break. If you love a parade, here’s a wearable synth that emulates a marching band.
[Kratz] just turned into a rock hound and has a bunch of rocks from Montana that need tumbling. This requires a rock tumbler, and why build a rock tumbler when you can just rip apart an old inkjet printer? It’s one of those builds that document themselves, with the only other necessary parts being a Pizza Hut thermos from the 80s and a bunch of grit.
Boot a Raspberry Pi from a USB stick. You can’t actually do that. On every Raspberry Pi, there needs to be a boot partition on the SD card. However, there’s no limitation on where the OS resides, and [Jonathan] has all the steps to replicate this build spelled out.
Looking for one of those ‘router chipsets on a single board’? Here you go. It’s the NixCoreX1, and it’s pretty much a small WiFi router on a single board.
[Mowry] designed a synthesizer. This synth has four-voice polyphony, 12 waveforms, ADSR envelopes, a rudimentary sequencer, and fits inside an Altoids tin. The software is based on The Synth, but [Mowry] did come up with a pretty cool project here.
Here’s an offer from Intel and the guy behind all of reality TV [Mark Burnett]: win a million dollars for making something. Pitch an idea for wearable electronics to the producers by October 2, and you might be on a reality TV show about building electronics which they’re calling America’s Greatest Makers. With this, Intel is promoting the Curie module a tiny, tiny SoC with Bluetooth, IMU, and DSP functions. We’re of the opinion that a Hackaday reader should win this contest, or at the very least be featured prominently in the show. No, it’s not Junkyard Wars, but it’s still a million dollar prize.
The Luka EV is a semifinalist for the Hackaday Prize, and a completely open, road legal electric vehicle powered by hub motors. It also looks really, really cool. Now, they’re selling them. It’s €20,000 for a complete car. Did I mention how cool it looks?
Boca Bearings is having a ‘Show Us Your Workshop’ contest, with the best (or should it be worst?) workshop winning tool cabinets, tool kits, a work mat, and calipers.
The EMU Drumulator is a classic drum machine that featured dirty 12-bit drum sounds in ROM. Now, it’s a single chip thanks to [Jan]. He’s done a lot of great work putting synths in single chips, and it’s great to see him move on to classic drum machines.