Arduino midi monitor

10/06/2010

When using the Arduino board with midi in, it’s necessary to set the baudrate to the midi standard of 31250. Unfortunately, this is a non-default baudrate so the Arduino Serial Monitor cannot display this serial data. Other solution are also dependent on standard baudrates (here) so these won’t work either. One way of working with this limitation is to switch baudrates during development, not very friendly.

I found a solution here which describes the possibility of using arbitrary serial baudrate using python (a very nice scripting language). Very smart solution which works great (on osx that is).

Download pyserial 2.5rc2
Unpack and open this new directory in Terminal.app (for example: username/Downloads/pyserial-2.5-rc2)
Install using: python setup.py install (my installed python version is 2.6.5)
Switch to the example subdirectory and type: python miniterm.py /dev/tty.usbserial-A6008i5n 31250 where tty.usbserial… is your Arduino serial port.

There are 2 comments in this article:

  1. 30/08/2010Alden M say:

    actually, assuming you are using an official arduino board or one of the FTDI cables, you can modify the driver to use baud rate aliasing to set a rarely used baud rate, like 300 or 1200, to run at 31250. then you just open up the arduino serial monitor and set it to the rate you aliased it to. this is documented in technical note 105: http://www.ftdichip.com/Documents/TechnicalNotes/TN_105%20Adding%20Support%20for%20New%20FTDI%20Devices%20to%20Mac%20Driver.pdf

    open the kext, open info.plist, find the entries with:
    idProduct
    24577
    idVendor
    1027

    and set config data to:

    ConfigData

    LatencyTimer
    2
    MIDI

    PortName
    MidiCable

    this will alias 300 to 31250

  2. 30/08/2010arthur say:

    thx, great tip! I will try this and report back as soon as possible.

    Real life is currently too busy (but most certainly not in a negative way) to work on this project. When I can find a little time, work on this project will resume!

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