MIDI problems using UNO and Macbook

Other Hardware Audio
1

UNO with Macbook Retina OSX 10.9.2

I have successfully uploaded a number of sketches via USB from my Mac and they continue to run without issue when the USB link is removed (external supply connected).

However there is a problem if I upload a sketch that involves serial transmission e.g. the Example 'MIDI'. It runs while the USB cable is connected (there is data transmission from TX i/o line and the TX LED lights), however if the USB cable is removed (external power connected), the TX transmissions stop (TX LED off).

Has anyone experienced this or similar?

Any help/thoughts would be appreciated

Thanks

2

Problem solved - not quite sure how, but it now works.

3

Your "problem" is that the serial link that is the USB is being used to send MIDI data into your computer. Remove that and how is the data going to get out.