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Topic: Mega 2560 MIDI controller issue (Read 3339 times) previous topic - next topic

happypay

Hello all,

I am very new to both the arduino and MIDI, so please if you think this is a relatively simple issue it likely is.

My arduino mega 2560 is currently powered by usb, with a midi-to-usb cable attached to the TX pin (midi) and com port 4 (usb). I have uploaded the midi example and the following was spit out by MIDI-OX:

example code: for(int note = 0x1E; note < 0x5A, note++ ... )

//
001014C7   1   1     B3    36    00    4  ---  Control Change   
0010158F   1   1     93    56    01    4  D  6 Note On         
00101658   1   1     FF    --    --   --  ---  System Reset     
00101658   1   1     93    32    00    4  D  3 Note Off         
00101720   1   1     93    73    56    4  G  8 Note On         
001017E8   1   1     93    01    2E    4  C#-1 Note On         
001017E9   1   1     FF    --    --   --  ---  System Reset     
001018B1   1   1     93    00    53    4  C -1 Note On         
001018B1   1   1     93    56    01    4  D  6 Note On         
0010197A   1   1     FF    --    --   --  ---  System Reset     
0010197B   1   1     93    2A    00    4  F# 2 Note Off         
00101A42   1   1     93    33    56    4  Eb 3 Note On         
00101B0A   1   1     93    01    26    4  C#-1 Note On         
00101B0B   1   1     FF    --    --   --  ---  System Reset     
00101BD3   1   1     93    00    13    4  C -1 Note On         
00101BD5   1   1     93    56    01    4  D  6 Note On         
00101C9D   1   1     FF    --    --   --  ---  System Reset     
00101C9F   1   1     93    22    00    4  Bb 1 Note Off         

To clarify, these notes only play about once every 7 seconds. The rest of the scrolling midi code is: key aftertouch, pitch bend (occasionally), and channel aft. I am very confused. I have ready in a separate post that having the arduino powered by the usb cable can cause issues ... is this the case here?

Could it also be a baud rate rate issue? I have the arduino code baud rate set to 31,250 of course, but the usb port is still set to 9600... I am under the impression that the midi-to-usb cable handles this issue as I have seen in other arduino midi builds but I am uncertain.

Any suggestions? Again, I am a noob at this sort of thing, though I have to admit I love the arduino so far ... I can see its potential use in future projects of mine. Any help would be greatly appreciated!! And I apologize for posting something like this if I was not supposed to, honestly this is the first "post" I have ever made ... as I said, total noob lol.





WilliamK Govinda

Maybe I'm just tired and can't picture this, but how are you doing the connections again? Midi-to-USB cable? You can't just plug a MIDI wire to the Midi Input of your computer, it just won't work. Maybe take a picture and show to us?

Usually you need some extra hardware in order to use the Arduino's UART (Serial Input/Output) as a MIDI device. For output is easy, just a resistor usually do the trick. But for Input is a bit more complicated.

Wk

happypay

Thanks for the reply WilliamK!!

Currently I have a MIDI connector wired to the arduino mega 2560 in the typical fashion, see the following:

http://arduino.cc/en/uploads/Tutorial/MIDI_bb.png

My wiring is identical to this. It should be noted that I am only interested in sending MIDI data, not receiving. Then, connected to the MIDI connector, I have a MIDI-to-USB (eMedia) cable:

http://www.bestbuy.ca/en-CA/product-alternate/usb-midi-keyboard-interface-kit/10152316.aspx?path=c1eb329f0b59fdf9a600d3c55be39584en13

This cable is connected to com port 3 on my laptop through the USB. The LED built into the cable blinks according to the delay I have coded into the MIDI program. I was under the impression that the MIDI-to-USB cable took care of the conversion/baud rate issues, but then again that's an assumption. Though I have connected this device to a CTK-601 using a MIDI-to-MIDI cable with no avail .... frustrating.

As for the project itself ... ultimately I want to construct a laser harp with a series of photoresistors connected to the analog inputs. When the beam is broken, play a note, simple ... or so it would seem.

Does that help? Ask me to design a dye laser pumped Ti:sapphire laser and it would be a piece of cake ... ask me to code MIDI, well, you've probably guessed that it would be difficult for me. Thanks again, I really appreciate the feedback!

DrSpeed

Hmmm, I'm not sure where things are going wrong. I've done this many times.

Be careful of the wiring of the midi cable. The diagram shows a female connector, but it's easy to confuse this and get things backwards if you are using a male connector.

Can you test your MIDI->USB to make sure it is working correctly?

Can you use a program like midiOX to monitor in the input of the midi port? If you have the midi traffic indicator light going (as you do) you must be close.

-Dr. Speed

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