[sdiy] MIDI & DIN Sync in the same connector?

[Joe Grisso]

On Wed, May 23, 2012 at 5:45 AM, Florian Anwander
<fanwander at mnet-online.de> wrote:
> Am 23.05.2012 00:40, schrieb Joe Grisso:
>
>> fill, continue, etc. on pins 4 and 5 (which are dedicated to MIDI).
>> That seems a bit dangerous to me.
>
> I don't think that is is dangerous. Both are systems basically low current
> 5V connections. Neither DIN-sync signals would break the optocoupler, nor
> MIDI would kill the transistor buffers at the input.

>From a circuit damage perspective, no. There isn't any danger.
However, from a functionality and user/customer operation perspective
(or lack thereof), it could create confusion and frustration on their
part when product X will work with their setup but product Y won't.
It's easy to troubleshoot, but as Magnus said earlier, the added pair
of connectors add negligible cost to the overall device while removing
this incompatibility in the boundary cases.

> Also you always sould place a kind of selection, which of both inputs is
> selected. So there should be no error.

Definitely. However, IMHO this would only present a clear advantage in
a space-constrained system. A physical switch is more expensive than
the corresponding pair of DIN jacks, and software control of the same
type of active switching system is more effort than just splitting the
functionality out into a separate pair of jacks. If you want the
challenge, go for it, but it seems that practicality of this kind of
implementation would only fit a project/product with a very small form
factor.

-- 
Joe Grisso
Detachment 3, Ltd.