Midi Problem

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi There,

I have followed the instructions in this tutorial:
http://itp.nyu.edu/physcomp/Labs/MIDIOutput

and I believe I have assembled everything correctly.

It does work, but there is one problem.

The midi program I am using on my mac to read the midi data (garageband) constantly reads a low A# in the (delay) spaces when no note is played.

Does anyone know why this would be?

2

I guess my problem is this.

I am writing a sequencer app, and I have a the arduino sending info to a 4079 chip, to control some LEDS.

I then have the arduino sending data to a midi jack, to create the audio.

The LED code uses 'digitalWrite' to send the information, but the MIDI code uses Serial.print.

I think these two methods are conflicting with eachother.

It seems that the LED code is causing this note 'interference'.

I assume this because the MIDI code run by itself runs perfectly, and has no low A#.

Can someone explain how these two methods may be interfering with eachother?

I think I'm missing something pretty obvious :slight_smile:

Thanks

(clarification: the problem is that the midi output has a humming note during playback, which garageband reads as a low A#. So low that it sounds like a rumble.)

3

The two are compatible providing you are not trying to use Pins 0 & 1 for lighting LEDs. These two Pins are used for serial communications and that is what the MIDI is using. So if you avoid using these then there will be no problems.