Musical maker Tim Alex Jacobs has constructed a synthesizer which turns a standard piece of lab tools on its head: the {Hardware} Reverse Oscilloscope 2, which supplies you the choice to design a waveform by means of slider switches.
“The unique {hardware} reverse oscilloscope was an analog multiplexer, pushed by a binary counter, pushed by one among my tiny square-wave midi synths,” Jacobs explains of the undertaking’s historical past. “I preferred very a lot the way it was simply easy {hardware} – and the design meant it was utterly freed from aliasing. I wished this to be all {hardware} too, even though I wished it to have much more options.”
2015’s {Hardware} Reverse Oscilloscope served as the idea, however 2023’s undertaking reboot is a significant improve. On the board’s coronary heart are not any fewer than three microcontrollers: a Raspberry Pi Pico, a Teensy 4.0, and a Microchip ATmega328P. These, in flip, deal with a 16-bit analog to digital converter as a pitch enter, 16 sliders and the identical variety of jobs and jacks by means of a pair of 16-channel analog multiplexers, and 16 LEDs — plus an audio output courtesy of a PT8211 digital-to-analog converter (DAC) linked over I2S.
The concept is straightforward sufficient: the 16 sliders are used to regulate the form of the ensuing audio waveform, performing precisely the alternative job to an oscilloscope by producing a sign from a form reasonably than producing a form from a sign.
The synth makes use of three microcontrollers, although Jacobs admits it could possibly be simplified to fewer. (📷: Tim Alex Jacobs)
“We may trivially flip this right into a MIDI controller,” Jacobs notes of the design. “Both by augmenting the [Raspberry Pi] Pico firmware or including one other microcontroller to eavesdrop on that serial information. I am unsure there’s a lot want to do this although.”
The total undertaking write-up is out there on Jacobs’ web site, although neither design recordsdata nor supply code have been revealed. “Sooner or later sooner or later, I’ll publish the supply code for the microcontrollers on this undertaking,” Jacobs guarantees. “In the event you assume the wiring’s a multitude, effectively, the much less stated concerning the supply code the higher.”