In response to the poster who was interested in controlling a
serinette with MIDI [181207 MMDigest], I sent the following reply.
Just today I got the sample boards for the more advanced version
of my decoder that can handle 128 notes, tested it, and it works.
On Monday I will get the boards for the simple 24-note version.

There are many ways to control pipes and levers, etc., with MIDI.
Commercial decoders are available that receive MIDI data from any
standard source and operate electronic switches which can control
solenoids.  They range from inexpensive for just a few solenoids to
rather expensive.  In addition you need to connect to the MIDI source
whether it is a computer, or a phone, etc.  This is usually done with
a USB to MIDI interface.

I am currently designing an open source Arduino-based MIDI decoder with
USB interface combination that can be assembled for very little money.
I will be presenting it at the 2019 AMICA national meeting in Seattle
in July.  The system can be assembled in a number of ways.  For someone
who has limited soldering skills and no access to a cost effective PC
board fabricator, it can be built using plug-in wires and ready made
boards that are available from China at very low cost.

A better option is to solder the components onto a custom made board.
I have test boards arriving today.  Both the Arduino code and the files
to make the boards will be freely shared with others.  There are two
versions of boards.  One is specifically made for very small organs and
is limited to 24 solenoids running at up to 50 volts and drawing 0.5
amperes each.  The one little board has the complete system.  The total
cost would be less than $60 to assemble if parts are carefully sourced
and a few units made at once.  The other system uses up to 8 boards,
each of which controls 16 valves.  It can operate solenoids with twice
the current requirement or 1 amp.

I should be able to test the larger system today as those boards are
arriving today.  The 24 solenoid boards will arrive on Monday.

Spencer Chase