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Rockbox mail archiveSubject: Re: AW: AW: AW: AW: Still Problems with AJB RemoteRe: AW: AW: AW: AW: Still Problems with AJB Remote
From: Ronald Teune <rtwolf_at_gmx.net>
Date: Wed, 14 Jul 2004 21:20:41 +0200 Hi, how did you simulate this? This schematic is exactly the same (IIRC) as used in old Diode Logic (but now only 1-input nand) so it should work... 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; when the uC Out port is at 5 V, the AJB remote is at ~5 V due to the pullup. (it's easy to make mistakes though, with this kinda stuff, especially since it's holiday - so correct me if i'm wrong) Perhaps PSPICE has some problems with grounding and stuff; how exactly did you connect a ground to this schematic? <snip> > # Forget what I said and simplify to this: > # > # +5V > # | > # | > # +-+ > # | |4.7k > # | | > # +-+ > # | > # | > # Schottky | > # uC Out port--------|<|---------+-- AJB remote > # > # The pullup won't hurt even if a box already has one. The diode will > allow > # your uC to pull the pin low, but will prevent it from being > # driven with high output current to 5V. Instead it "gently" floats up > via > the pullup. Use a > # Schottky because those have low voltage drop across, allowing for a > better "low" level. > > Ok, I also did a PSPice simulation of this (with 1N4148 because the demo > doesn't have a Schottky). > The AJB remote level then toggels between high = 0,7V and low 0,612V ??? > > Well, I know, that these simulations are not very well done, but in > previous > cases it worked > more or less like the final HW. <snip> Greets, Ronald Teune _______________________________________________ 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 |