Uploading MIOS/apps without MIDI or optocoupler

[rasteri]

Hi,

I was wondering if it's possible to upload MIOS and an app (in my case, a custom written C app) to the PIC without using MIDI in? I ask because I have no spare optocouplers and I can't get to any electronics shops in the next week or so. My PIC programmer works fine, I've burned the bootloader and I am getting upload requests from the MIDI out.

Alternatively, is there any quick way of interfacing the PIC to the midi port without using an optocoupler? It's not permenant, just to get one program loaded....

[nebula]

The whole point of the optocoupler in the MIDI spec is to prevent ground loops.  You could probably bypass it in most circumstances, but you theoretically risk blowing up your PIC (or the MIDI OUT of the sending unit).

I HAVE NEVER TRIED THIS, AND I DOUBT I EVER WILL.

If you are in North America, phone Digi-Key (1-800-DIGI-KEY) and tell them you need a 6N138QT-ND.  Including shipping and handling, it will cost you about the same amount as a new PIC, but you will have an opto in your hands tomorrow morning at 9:30.

[stryd_one]

Welcome aboard.

No, you do need midi to upload mios and apps. You can't burn them.

Yes, you can skip the opto. But it's there for good reason.

Patience is a virtue. You should wait, in my opinion. You'll live.

[rasteri]

I'm in the UK. Guess I'll just have to order one from Maplin.

Burning MIOS and an app in one hex file using a PIC programmer would be useful though - that means smaller cases, fewer components, faster programming time etc.

Wouldn't it be possible to patch the mios hex file from locations 00003000 onwards with the hex from the application? Or does MIOS/the bootloader do some more complex stuff?

[cimo]

rasteri

i can ship to you a optocoupler for free the 5th of march from the canary islands, that means it ll take about a week

Simone

[nILS]

that means smaller cases, fewer components, faster programming time etc.

* smaller cases: build your own core module on veroboard or etch it/have it etched, go SMT

* fewer components: just don't stuff it

* faster programming: Removing the PIC from a finished and closed case, sticking it into the burner, burning it, putting it back on the board and closing a case is faster than the 3-click MIDI version? Remember that you'd have to do that for every software update...

It might be good for your project, but you've got to keep in mind that a lot of people are using the boards for various projects. Most of them don't make any sense without a MIDI In. And I honestly doubt that it's really good for your project - leaving out this $0,10 part's got you waiting for a couple of days now ;-)

[rasteri]

As luck would have it, a friend decided to pay me a visit, so I got him to go past maplin on the way here :)

Thanks anyway. No doubt I'll need your help when I can't get the optocoupler to work...

[Wilba]

- leaving out this $0,10 part's got you waiting for a couple of days now ;-)

Can I emigrate to this fantasy land you live in where optocouplers are $0,10?  ;D

[nILS]

Can I emigrate to this fantasy land you live in where optocouplers are $0,10?  ;D

Sure you can, but resistors and low cost LEDs cost $50 a piece here :D

_{Okay maybe $0,10 was a bit off (by about $0,30), but it illustrates my point.}