[vdr] Re: Plugin & Diseqc Question to Klaus & all

["Reinhard Walter Buchner" <rw.buchner@freenet.de>]

Hi Klaus, Rene, Christian,

K>The 22kHz signal is nothing that is "sent" once. It is
K>either _on_ or_off_.

Okay, but is the 22kHz simply "there" and the devices
automatically get activated when they receive the signal?
Or do the devices ,which use the 22kHz signal, only get
activated on the "steigende Flanke" of the signal? Or does
the 22kHz signal maybe even deliver a PCM (or other)
coded start-up signal?

K>so it shouldn't matter where the 'T' is. Once executing
K>the DiSEqC command string has come by a 'T', the 22kHz
K>tone is turned on and stays on

Hmm, I will try this again, but I could have sworn, if I move
the "T" in front of the W52000, it didn`t work. I will try this
again.

K>Are you saying that the motor draws its entire current from
K>the LNB power?

Yes (looking innocently around ;o)). I have checked the DVB
card several times after moving the motor back and forth
between Astra and Hispasat and nothing gets really warm. I
can touch all parts of the DVB circuitry w/o fear of getting
burned. My cheap Skystar2 which I use for Internet and
webcasting gets quite a bit hotter eventhough it doesn't have
to drive a motor (LNB only). No, for your next question ;o)
I don't have this card installed at the moment.

K>Driving a motor must require quite a current - drawing this out
K>of my DVB-S card would really scare me...

As I said 350mA at start up and moving ~~200mA. The motor
is extremely geared down, so the dish weight, wind ,etc doesn`t
really load the motor that much. Before I installed the motor
on the roof I tried to stall it by hand, while it was moving (using
my Nokia). It wasn`t possible to stall it (although I didn`t measure
the current draw that time). Motors will only receive a certification,
if they draw less than 500mA at any time. It shouldn`t be a power
problem, because if I use the 52 second delay, VDR works perfectly.
The problem of cousre being that I cannot predict in which order I
will zap channels, so W52*10^3 only works for a direct change
between Astra and Hispasat.

Klaus: while writing my answer to Christian below, I just realized
something: What does VDR do (in terms of tuning & diseqc), when
I tune to exact the same channel (i.e Pro7 and next channel is also
Pro 7)? The reason I am asking, is that this will also restore a
picture to my TV, if I didn't choose a high enough value for the W
command. You say above the diseqc commands (or parts if I understood
it correctly) are only send if they are different. How does VDR
know this? Does it actually check DVB hardware registers? Or does
it simply check a variable, to see if the value has changed? To be
exact: What is done to the DVB (tuning, init, diseqc, etc) if ALL
the parameters are the same?

I tried Bernd Schweikerts LCD-Motor patch for Version 0.98. This
version works. I can tune to a new satellite, the motor moves and
I get a picture on the TV after the new satellite is reached. However,
his version uses X for the motor controls (which I won`t have, once
I install VDR on my actual box). I used the same DVB driver (yours)
for both the 0.98 version above and the 1.1.13, so, it shouldn't be a
DVB driver problem.

I think I will make myself a Y adapter and actually hook up an o-scope
to the LNB line. That way I can see what is happening and also can
measure the line voltage while it is being loaded with the motor.

Christian wrote:
>My StabHH100 rotor only moves at 18V. This seems to be a
>common problem with this type of rotor, which uses the lnb
> voltage to move. But it is not a DVBs  specific issue, other
> receivers suffer from this, too.

Hmm,  "I" don't have this problem with my rotor. Using it either
with my Nokia or the DVB card, you can actually hear what
voltage is being used as the tone of the motor changes, depending
on whether it is receiving 13V or 18V

>Another observation is, that the LNB is not turn off, when moving.

Okay, that was just a guess on my side. Most likely Nokia also
switches the stream output off, to while tuning.

Btw Christian: my problem isn't getting the motor to move, but rather
having the DVB put a signal back on the TV after the dish has finished
moving. If I change the Wxxxx to something less than the motor needs
to reach the position, my TV remains black. E.g. the move takes 40sec
and I put a W35000 in the diseqc.conf, then my TV stays black. That is
what I don't understand. I would expect VDR to say can't sync to channel
xyz a few times and / or maybe raise the panic level once and then
show the picture, but it doesn`t. The TV stays black! I then have to
reselect the same or a different channel (but on the same satellite) to get
a picture on the TV. My next problem is that I cannot say in which order
I will select the satellites while zapping through the channels, so it is
impossible to assign a fixed value for each Wxxxx in the diseqc.conf.

Rene wrote:
RW> Yes, I understood that, but maybe the 22kHz never reaches the LNB
RW> > due to motor movement. It might also be that the motor actually
RW> > switches the LNB off during movement as the DiSEqC specs say
RW> > a maximum of 500mA to any diseqc registered product. By switching
RW> > the LNB off, they save current and prevent pops, clicks and other
RW> > glitches while the motor is moving (YOU turn Pids off in VDR,
RW> > but maybe some elcheapo receivers don't) and from annoying the
RW> > viewer. My Nokia goes black during the motor movement, so
RW> > maybe the LNB is really switched off.

R>If so, you could repeat the DiSEqC-command instead of the Tone-command ...

Hmm, not quite sure what you mean. What would this change (in
terms of DVB control over the LNB)? I did try a diseqc.conf where
I repeated the actual motor command 3 times (as suggested in the
diseqc specs). It didn't change the behavoir. I must admit, I don't
remember if I was using the "T" or "t" command during that run. Do
you mean the 22kHz would be switched on if I just run the diseqc
hex sequence more than once?

Greetz,
Reinhard



-- 
Info:
To unsubscribe send a mail to listar@linuxtv.org with "unsubscribe vdr" as subject.