works: MIDI-IN: code + schematics

Forum 2005-2010 (read only) Hardware Interfacing
16

ccgibson,
i know about the pain to debug this.

Some of the steps I've tried:

  1. I've verified my input pin works using a simple potentiometer. I can get Serial.Available to read an input byte with that set-up
  2. I've tried both midi plug wiring options as described in this thread.
  3. I've tried the circuit with and without the diode.

if you are already getting some serial data, i'd suggest checking just for a "144" (note-on message). Every keystroke should cause at least one.

 if (Serial.available() > 0) {
    blink(); //once to signal at least something arrived

    // read the incoming byte:
    incomingByte = Serial.read();

    // wait for as status-byte, channel 1, note on 
    if (incomingByte== 144){ // note on message starting starting
      // yeaha, we're getting something
      blink();
      blink():
      blink();
    }
 }

if you're not receiving any data, you most likely have a problem with the opto setup. are you using the 4n28? can you verify that the optocpupler [still] works?
i'm not sure about your 2-watt resitors, but if they're that big, i could imagine them adding some noise. still i think you should get correct data in one of let's say a 100 key strokes.

remember that you need to set your keyboard (or whatever midi device you'Re using) to use midi channel 1 to use it with this code here.

good luck,
kuk