2016-12-27 (Tu) Tough Pi-ano

If the octaves were going to play nicely with each another the first step was going to be to find a combination that worked. Yesterday it became apparent that mixing controllers wasn’t viable because the Teensy controller booted the USB↔MIDI adapter every time. This problem had several potential solutions. None were guaranteed to work.

One possibility with a high likelihood of working was to replace the tablet with a more expensive Windows 10 tablet. Windows ten, with a multitude of synthesizers, would undoubtedly have a free version capable of playing from multiple MIDI sources.

The second possibility was using an Arduino Mega with enough discrete inputs to monitor every key. This would mean a lot of wire running from the central board to the keys. In order to remain modular the wires would have to disconnect with a connector that had at least 13 connections. To make matters worse the MEGA doesn’t make it simple to act like a MIDI device.

Building on the idea of a single controller there was also the possibility of using I/O expanders in each of the octaves. A 16 position bit shift register would allow a simple data line to run between a central Teensy and each octave. Since a single Teensy already worked well with the Android tablet this would be a good option. Experience in the past with bit shift registers did make this unappealing. Despite considerable effort I could never get an I/O expander to work.
Another possibility was using identical MIDI controllers. Mixing different types didn’t work well on the simple Android app but if they were identical it might eliminate the conflict. The first aspect was which style to double up on? Using more Teensy controllers would be expensive, but within reason. Using more USB↔MIDI adapters on cheap controllers was doable. But the USB↔MIDI had already proven flaky.

Another option that line of thinking, albeit an expensive option, was to use a 4-port MIDI↔USB adapter. The 4-port version probably had a better chance of working since the tablet would only see a single MIDI source and multiple sources was the first problem. But it was prohibitively expensive yet within reason. Another advantage was that MIDI DIN cables were durable, inexpensive and easy to buy. They would make a good connection between the octaves and adapter.

The first approach was to try to find other controllers which could emulate a USB MIDI device. Teensy controllers weren’t on hand. Arduino Micros were available though. Most of the day was spent trying to make a Micro talk MIDI to an Android. It didn’t work. More time could have been spent and it would have worked eventually but it seemed wise to accept the loss of the time-gamble and move on. There was no guarantee that multiple Micros would even work together.

One final time-gamble for the day was to go to a local computer store which had an assortment of maker supplies including Arduinos and I had seen a Teensy there before. A store associate helped look but none could be found. Despite scouring the section to look for the small board it could not be found. One happy note was that they had a full stock of Raspberry Pi Zeros which I had planned to use in my laser tag project.

The rest of the posts for this project have been arranged by date.

First time here?

Completed projects from year 1.
Completed projects from year 2

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2016-05-25 (W)