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Rockbox mail archiveSubject: Re: AW: AW: AW: AW: AW: Still Problems with AJB RemoteRe: AW: AW: AW: AW: AW: Still Problems with AJB Remote
From: Ronald Teune <rtwolf_at_gmx.net>
Date: Wed, 14 Jul 2004 23:20:26 +0200 Hi Matthias, On Wed, 14 Jul 2004 22:17:54 +0200, Matthias Klumpp <Matthias.Klumpp_at_gmx.de> wrote: > Hi Ronald, > > # What if we used standard 1N4148 diodes? > # The voltage drop on the Schottky diode is 0.6 Volts. > # If the uC out port is at 0 V, the AJB remote line will be pulled > # down to 0.6 V; > > Isn't it less voltage drop in case of a Schottky ? > As I understood Jörg, he wants the Schottky because of a lower voltage > level > than 0.6V when the uC port is 0V. I meant to say I was doing in-brain circuit simulation with standard 1N4148, but perhaps wasn't very clear :-) > # when the uC Out port is at 5 V, the AJB remote is at ~5 V due to > # the pullup. > > That's still making me ?????????, because I still have that 5V level on > the > JB side. > What if I make a resistor voltage devider, that makes the pull-up pull to > 3.3V, like this: > > +5V > | > | > +-+ > | |12k > | | > +-+ > | > +-----------------+ > | | > +-+ | > | |22k | > | | | > +-+ | > | | > --- | > | > Schottky | > uC Out port--------|<|---------+-- AJB remote > > # (it's easy to make mistakes though, with this kinda stuff, > # especially since it's holiday - so correct me if i'm wrong) > > You are wrong - still NO holidays in Germany ;-))) > Even so it's already a little bit late here and forthermore after a hard > days work.... > maybe therefore ? Hehe... again I probably was unclear... I meant that _I_ had holiday, so _I_ could be wrong :-) That voltage divider thingy is probably cool too. Maybe the best and fastest way to correctly simulate is just take 5V, a multimeter, a diode and two resistors :-) > # Perhaps PSPICE has some problems with grounding and stuff; how > # exactly did you connect a ground to this schematic? > > Well the schematic is only "the upper half" of the circuit. > I've taken a pulse generator symbol to get a 20ms/5V rectangle signal as > the > uC out. > On the AJB remote side I have a 1M resistor to ground (simulating a high > impedance input). hmm... sounds right... well, whatever :-P I would like to build a remote too, I think it'll be quite useful. And the one Steve Russel describes seems dirt cheap, so why not... the problem would be a decent, small enough box to put the buttons and PIC in and not to be too big. Is your design better? ;-) > Greetings > > Matthias > > _______________________________________________ > http://cool.haxx.se/mailman/listinfo/rockbox > Greetings, Ronald (aka zeekoe) _______________________________________________ http://cool.haxx.se/mailman/listinfo/rockbox Received on 2004-07-14 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |