[sdiy] Problem with Groove Electronics Jupiter 8 interface

[John Speth]

> I have here a Jupiter 8 with a Groove Electronics MIDI-Interface, which
> immediately reboots as soon as it receives any MIDI command.

Not knowing much about the Jupiter 8 and nothing about the aftermarket
MIDI interface, I can only guess:

Since it's aftermarket, the wiring connection between the new HW and the
synth are probably not optimal.  My guess is that one or more connections
are broken.  My hypothesis is that a MIDI byte is captured by a UART, then
interrupts the synth microcontroller, the interrupt handler never returns
and a watchdog reset happens.  The interrupt handler never returns because
whatever UART interrupt clearing operation that needs to happen isn't
happening because of the broken connection.

JJS