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Author Topic: Mega 2560 compatible MIDI shield?  (Read 2117 times)
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Nice, France
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Is anyone aware of a Mega 2560 compatible MIDI shield?

I have the Rugged Circuits Flexible MIDI Shield which is nice for the Uno - same size, choice of using Serial or using SoftwareSerial with jumper pins on the shield.



Naturally it fits on a Mega 2560, since the first four blocks of pins are the same, but:

  • analog inputs A6 to A15 are blocked
  • comm pins 14 to 21 are blocked
  • anything plugged into digital pins 22 to 53 blocks the MIDI ports

or in other words, most of the extra features that would lead you to select a Mega in the first place become unusable.

Also, giving you a choice of Serial1 (shared with the USB) or SoftwareSerial (lots of CPU useage, constrains use of interrupts) is fine for an Uno but not needed on a Mega which also has Serial1, Serial2 and Serial3 driven by UARTS.

I have tried connecting the sheild with jumper wires instead of stacking it with the pins, it works OK on Serial but  did not work when jumpered over to Serial3.

Any suggestions for a better shield? Or suggestions on what else I should do to get the shield to work?
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Nice, France
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By 'better' I mean one that can be used with the other three serial channels, and one that does not obscure the input and output pins on the Mega 2560.

Suggestions for a Mega-compatible MIDI-over-USB solution (using a separate USB connector, not the one on the Arduino) would also be welcome.
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Lake Tyers Beach
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Hi I have gone in a slightly different direction.  I have combined the Fluxamasynth board with a Mega2560.  The conversion was very easy as I had been previously using a 1980's Roland classic stand alone synth' on a Uno board and all I had to do was change the code to

Code:
    Serial2.begin(31250);


And connect the center pin of the fluxamasynth jumpers by soldering a half a prototyping cable to that center pin and poking it into Pin 16 socket on the Mega board.  The signal was 5V, standard logic compatible, straight through!

It meant I could debug with the standard serial interface and simply direct all midi controls through Serial2 (ie Pin16).  I plugged it in, stacked on the Mega, and it worked first time.  A rare satisfying feeling  smiley

The Fluxamasynth is ideal for me as I wanted to create a portable device and did not want to lug around keyboards etc.  The quality for my purposes is excellent and has a wealth of features and I am not even going to elaborate on, but I believe it can also be driven by SPI techniques as well.  Given I have already got a 512k ram expansion and a OLED display on the SPI it was a relief to have the simplest midi interface work so easily.

Rob

 
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Lake Tyers Beach
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Hi Nantonos,
I did check those type of boards initially but given the simplicity of the midi interface I just made it up on a prototyping board with a flying 5 pin Din socket.  I also included the LCD and IR detector on that board as well.  However I eventually swapped to the Fluxamasynth board as it gave me a high degree of portability (one of my main design aims, as it is not much use having a highly portable instrument like a flute and then have to lug a huge midi key board for accompaniment).

The attached photos will give you an idea of what it looks like.  The center pin on the header on the Fluxamasynth board has a flying lead soldered to it that plugs in the Second serial output on the Meg 2560 board. Instant Midi  smiley

Cheers, Rob



* 2012-09-29 09.26.48.jpg (371.82 KB, 1600x960 - viewed 46 times.)

* 2012-09-29 09.23.43.jpg (352.87 KB, 1600x960 - viewed 38 times.)
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