Hello,
I came across this thread while looking for something else.
It prompted me to post - very much prematurely - a sketch that does Roland sysex: Merry music. Since I did that I discovered how to attach files to a post on this forum. The code is definitely not for the eyes of Inspector TidyCode, but it works. Well, it started working this afternoon.
One thing I forgot to mention is that if you send a sysex Data Request to a Roland JV, the response lacks the final F7. This might be troublesome if you locate the data you want by its distance from the end of the array. Perhaps I should configure the brilliant MIDI.h, as proposed, to insert the F0 and F7 automatically.
Another thing, if you send a Data Set sysex, make sure you put in a delay (Roland says 20ms, a source on the web says 40). The JV responds with some junk, perhaps to make sure you remember this.
Finally, the best way to use a MIDI shield with a Mega is to snip off the two serial (0) pins, and connect the shield to serial1. You need serial0 to see what your code is getting up to...
Temper7.ino (24.7 KB)