I just stumbled upon this blog, it looks like a very interesting source of music DIY projects!
Since the birth of audio electronics, the audio transformer has played an important role. When compared to modern miniaturized electronics, a transformer seems large, heavy, and expensive but it continues to be the most effective solution in many audio applications. The usefulness of a transformer lies in the fact that electrical energy can be transferred from one circuit to another without direct connection, and in the process the energy can be readily changed from one voltage level to another.
Thirty years ago, Dave Smith worked with Roland on a way to make synths and musical instruments communicate. They connected a JP-6 and a Prophet600, and MIDI was born.
Since then, it has been (and still is) at the heart of musical hardware, and even though the technology is behind other means of communications (Bluetooth, WiFi), its presence is still expected. What makes its strength is its simplicity: not much hardware is required, the messages are simple enough to be handled by a small microcontroller (or even discrete logic chips, with a bit of courage), and since it’s not in constant change, there is no need for updates or revisions.
The first MIDI device I made was actually not a musical device. It was an accelerometer-base inclination meter, made for a school project, and we figured out it was a convenient way of transmitting data between the board and the computer, since there was already a program on the other side that can understand the data. Then I started controlling MIDI effects, like the Digitech Whammy, from an Arduino, and that’s when I started developing the MIDI library.
I’m starting the beta of the Arduino MIDI Library version 4.0.
It includes the following changes:
- Support for SoftwareSerial
- Multiple instances (a merger demo has been added to the examples)
- Refined build options
- Support for other targets than Arduino
Eli Hughes made this awesome PCB pickguard for his entry in the Freescale Kinetis Make It Challenge. It contains a Freescale Kinetis ARM Cortex M4 processor with DSP extensions to process the guitar signal, providing both an analog and digital audio output.
He also release a video with the details of all the maths and physics explained, as well as the hardware design.
Code and schematics are available here.