[sdiy] bizarre pic-midi issues

[cheater cheater]

Ask on the ucapps forums and see if they can tell you what bugs they ran into

D.

On Sun, Apr 18, 2010 at 00:45, Karl Ekdahl <elektrodwarf at yahoo.se> wrote:
> Ingo, Csaba;
>
> I tried changing the resistor to a 1K but the 6N136 couldn't pull it all the way to ground, so i changed to a 2.2K which gives me the same results as before. However i did verify that the opto and everything works 'cause i connected it to a couple of gates to make a MIDI THROUGH and the synth at the end of that responded nicely.
>
> So yes, there is indeed a problem inside the PIC however i'm still inclined to believe that the clocking is correctly set because
> a) it works with MIDI OUT, and
> b) it gives me good data almost all the time while any setting higher or lower gives me framing errors all the time.
>
> But regardless i could of course be wrong, please prove that it's so! :) I am inclined to believe at this point however that i indeed am dealing with a silicon bug, i noticed that this chip is a revision A3 which does have silicon bugs in its EUSART *but* none of the bugs mentioned in the six erratas i have are pertaining to asynchronous reception in 8-bit mode. Nevertheless, i placed an order with Mouser in the hopes of getting a never revision chip.
>
> Karl
>
> --- Den lör 2010-04-17 skrev Csaba Zvekan <czvekan at gmail.com>:
>
>> Från: Csaba Zvekan <czvekan at gmail.com>
>> Ämne: Re: [sdiy] bizarre pic-midi issues
>> Till: Synth-diy at dropmix.xs4all.nl
>> Datum: lördag 17 april 2010 22:18
>> I use a 6n135 with a 1K pull-up and a
>> 0.1µF capacitor to ground. It works like a charm . Ingo you
>> have a valid point there . I still think his problem is
>> clocking and settings.
>>
>>
>> On Apr 17, 2010, at 10:02 PM, Ingo Debus wrote:
>>
>> >
>> > Am 16.04.2010 um 20:19 schrieb Karl Ekdahl:
>> >
>> >> The hardware i'm using is a PIC18F4550 connected
>> with it's RX pin tied to pin 6 of a 6N136 via a 2.7K pull-up
>> resistor,
>> >
>> > In the Fairchild datasheet of the 6N136 propagation
>> delay times are specified for a pull-up of 1.9k. Admitted,
>> 2k7 isn't that much more, but maybe its worth a try using a
>> smaller pull-up to speed up the optocoupler?
>> >
>> > Ingo
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