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Subject: AW: Still Problems with AJB Remote
From: Matthias Klumpp (Matthias.Klumpp_at_gmx.de)
Date: 2004-07-10

Hi all,

# -----Ursprüngliche Nachricht (Jörg) -----
# Can't you power the Atmel with 3.3V as well?

Of course I could, but my other signals that I'm emitting need a 5V level.

# > If I connect a open collector transistor stage [...]
#
# Such a transistor stage would invert the signal. I guess the average
# erceiver is not happy with that... ;-)

In fact there are two npn transistors to have the correct logic.

# > Does anybody know, what are the differences of the remote input circuit
# > inside the Studio Player's, old Recorder's and newer
# Recorder's (like V2)
# > ?
#
# Thare should be none, except for the strenght of the pullup.

I think there are some !

If I measure into teh NOT connected remote pin of my Studio, I have 3.3V
-> There is a pull-up

If I do the same with 2 Recorders, I measure 0V.
-> So there is NO pull-up and the input has to be driven actively.

# > Maybe anybody has a schematic ?
#
# See the ducumentation pages.

I did, but unfortunately I'm not able to locate the serial port and its
connection.
Maybe you could give me a hint ?

# The universal bidirectional solution is that circuit with a MOSFET
# inbetween, preventing the voltage to rise above 3.3V. I once
# posted that, am too lazy to dig it out right now.

Any idea which month/year or subject ?

THX

Matthias

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