Bringing Guitar Synthesis To The Microcontroller

April 10, 2018 by Brian Benchoff 12 Comments

If you’re working with audio in an embedded environment, the best option for years now has been the Teensy 3 microcontroller board. This choice has mostly been due to its incredible power and audio libraries, but until now we really haven’t seen a stompbox-style interface that used the Teensy to its fullest extent. Now we have, in [Wolkstein]’s GitSynth, everything you could want in a synthesizer that processes the signals from an electric guitar.

The core of this build is a Teensy 3, and all the audio goodies that come with that. Also included is a USB MIDI and audio interface, smartly both attached to a panel-mount USB-B connector on the back of the stompbox. Other controls include a single mono in jack for guitars and synths, two mono out jacks for stereo-ish output, a bunch of footswitches for bypass, tap tempo, preset selection, a jack for an expression pedal, and some buttons to move around the LCD user interface.

While putting a powerful microcontroller in a stomp box for is a project we’ve seen many times, this project really shines with the MIDI GUI that’s built for a device with a real display and a mouse. [Wolkstein] built a PyQt-based app for this synth, and it’s a plethora of buttons and sliders that looks similar enough to a real synthesizer. There’s enough configurability here for anyone.

You can check out the demo video (in German, but auto-translate subtitles exist) below.

Thanks [Mynaru] for the tip!

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Learn What Did And Didn’t Work In This Prototyping Post-Mortem

March 30, 2018 by Donald Papp 16 Comments

[Tommy] is a one-man-shop making electronic musical things, but that’s not what this post is about. This post is about the outstanding prototyping post-mortem he wrote up about his attempt to turn his Four-Step Octaved Sequencer into a viable product. [Tommy] had originally made a hand-soldered one-off whose performance belied its simple innards, and decided to try to turn it into a product. Short version: he says that someday there will be some kind of sequencer product like it available from him, “[B]ut it won’t be this one. This one will go on my shelf as a reminder of how far I’ve come.”

The unit works, looks great, has a simple parts list, and the bill of materials is low in cost. So what’s the problem? What happened is that through prototyping, [Tommy] learned that his design will need many changes before it can be used to create a product, and he wrote up everything he learned during the process. Embedded below is a demo of the prototype that shows off how it works and what it can do, and it helps give context to the lessons [Tommy] shares.

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Water Level Sensors, Alexa In A Fish, And Modular Synths During World Create Day

March 19, 2018 by Mike Szczys 3 Comments

On Saturday we saw a flood of interesting hacks come to life as more than 100 community organized meetups were held for World Create Day. Thank you to all of the organizers who made these events possible, and for everyone who decided to get together and hack.

Students Learning Hardware Design in Islamabad, Pakistan

The students at LearnOBots took on a slew of great projects during World Create Day like a smart medicine dispenser, electronics that control mains appliances, parking sensors, and a waste bin that encourages you to feed it. The group did a wonderful job of showing off their event by publishing several updates with pictures, stories, and video presentations from all the students. Nice work!

Daniyal LED Matrix

Haya and Taha water level sensor

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Google Builds A Synthesizer With Neural Nets And Raspberry Pis.

March 16, 2018 by Brian Benchoff 16 Comments

AI is the new hotness! It’s 1965 or 1985 all over again! We’re in the AI Rennisance Mk. 2, and Google, in an attempt to showcase how AI can allow creators to be more… creative has released a synthesizer built around neural networks.

The NSynth Super is an experimental physical interface from Magenta, a research group within the Big G that explores how machine learning tools can create art and music in new ways. The NSynth Super does this by mashing together a Kaoss Pad, samples that sound like General MIDI patches, and a neural network.

Here’s how the NSynth works: The NSynth hardware accepts MIDI signals from a keyboard, DAW, or whatever. These MIDI commands are fed into an openFrameworks app that uses pre-compiled (with Machine Learning™!) samples from various instruments. This openFrameworks app combines and mixes these samples in relation to whatever the user inputs via the NSynth controller. If you’ve ever wanted to hear what the combination of a snare drum and a bassoon sounds like, this does it. Basically, you’re looking at a Kaoss pad controlling rompler that takes four samples and combines them, with the power of Neural Networks. The project comes with a set of pre-compiled and neural networked samples, but you can use this interface to mix your own samples, provided you have a beefy computer with an expensive GPU.

Not to undermine the work that went into this project, but thousands of synth heads will be disappointed by this project. The creation of new audio samples requires training with a GPU; the hardest and most computationally expensive part of neural networks is the training, not the performance. Without a nice graphics card, you’re limited to whatever samples Google has provided here.

Since this is Open Source, all the files are available, and it’s a project that uses a Raspberry Pi with a laser-cut enclosure, there is a huge demand for this machine learning Kaoss pad. The good news is that there’s a group buy on Hackaday.io, and there’s already a seller on Tindie should you want a bare PCB. You can, of course, roll your own, and the Digikey cart for all the SMD parts comes to about $40 USD. This doesn’t include the OLED ($2 from China), the Raspberry Pi, or the laser cut enclosure, but it’s a start. Of course, for those of you who haven’t passed the 0805 SMD solder test, it looks like a few people will be selling assembled versions (less Pi) for $50-$60.

Is it cool? Yes, but a basement-bound producer that wants to add this to a track will quickly learn that training machine learning algorithms cost far more than playing with machine algorithms. The hardware is neat, but brace yourself for disappointment. Just like AI suffered in the late 60s and the late 80s. We’re in the AI Renaissance Mk. 2, after all.

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SID Organ Pulls Out All The Stops

January 2, 2018 by Kristina Panos 15 Comments

Someone left this organ out in the rain, but [Tinkartank] rescued it and has given it a new life as a SID controller. What’s a SID, you ask? That’s the sound chip Commodore used in the C64, a remarkable chip revered among retro gamers that was way ahead of its time.

He threw out everything but the keyboard assembly for the build. Each key press now drives a momentary button, and those are all wired up to an Arduino Mega through some I/O expansion boards left over from another project. The Mega drives the MOS6581 SID chip which generates those sweet chiptunes. There are four CV outs for expanding the organ’s horizons with Eurorack modules.

Our favorite part is the re-use of the stop knobs — particularly that they are actuated the same way as before. The knobs still technically control the sound, but in a new way — now they turn pots that change the arpeggio, frequency, or whatever he wants ’em to do.

The plans for the future revolve around switching to a Teensy to help out with memory issues. Although it’s a work in progress, this organ already has a ton of features. Be sure to check them out after the break.

Once you dive down the chiptunes rabbit hole, you might want to take them everywhere. When you get to that point, here’s a portable SID player. A SIDman, if you will.

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The Tiniest Of 555 Pianos

December 13, 2017 by Jenny List 23 Comments

The 555 timer is one of that special club of integrated circuits that has achieved silicon immortality. Despite its advanced age and having had its functionality replicated and superceded in almost every way, it remains in production and is still extremely popular because it’s simply so useful. If you are of A Certain Age a 555 might well have been the first integrated circuit you touched, and in turn there is a very good chance that your project with it would have been a simple electric organ.

If you’d like to relive that project, perhaps [Alexander Ryzhkov] has the answer with his 555 piano. It’s an entry in our coin cell challenge, and thus uses a CMOS low voltage 555 rather than the power-hungry original, but it’s every bit the classic 555 oscillator with a switchable resistor ladder you know and love.

Physically the piano is a tiny PCB with surface-mount components and physical buttons rather than the stylus organs of yore, but as you can see in the video below the break it remains playable. We said it was tiny, but some might also use tinny.

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Virtual Analog Synth Brings Tunes To The Masses

October 7, 2017 by Bryan Cockfield 19 Comments

Part of the problem with getting involved in a new hobby is the cost. Whether you’re learning to surf, weld, garden, or program, often the entry cost is several hundred dollars. We’re huge fans of things with low barriers to entry, though, so we were happy to see the latest project from [pappas.chris] which promises to introduce newcomers to the musical hobby of synthesizers for just over $20.

The build revolves around an STM32F7 microcontroller and offers a 6-voice virtual analog synthesizer. The build is expandable, too, so if you want to build on the STM platform with any other add ons the process is relatively simple. This might not be necessary for a while, though; the current iteration offers many features that a typical synthesizer would have. Exhausting the possibilities with this tiny device will take some effort.

Since the synth is built on a common microcontroller platform, it’s easily programmable too, which isn’t often a feature of commercial synthesizers. You can listen to a sample audio file on the project page, and get started building your own as well. If you don’t have your own keyboard to use with it, there are other DIY synths that cover that area as well.