[mythtv] Ticket #1945: DVB-S/diseqc patch

Mark Buechler mark.buechler at gmail.com
Mon Jul 17 17:55:04 UTC 2006

I've been testing this branch for several days now very successfully. My
setup is as follows:

1. Quad (circular/linear) LNB behind a rotor configured for 8 orbital
locations ranging from 61 degrees to 130 degrees (lower ones not tested due
to an annoying tree in my yard). Between the LNB and the rotor is a 4-port
DiSEqC switch, two ports in use from the quad-LNB.

2. Single LNB on a stationary dish hanging off of port 3 of the 4-port LNB
behind the rotor.

3. Two sources connected to a single stationary LNB (each source with a
different LOF).

4. Two LNBs connected to a stationary dish configured with two sources
available on two DVB cards. Connecting these LNBs is a built-in 2-port
DiSEqC switch. One source is shared with the #2 above. These LNBs are

I have a total of 4 DVB cards in use (Genpix, SkyStar2, 2x Twinhan) so my
setup is not trivial. As far as I've tested, I've only seen one issue wrt to
the two Twinhan cards connected to the bandstacked LNBs and 2-port switch
where the switch did not switch properly. I've not been able to reproduce

I have two suggestions for this branch:

1. Allow a rotor position of "none" to be entered in for an orbital location
which would result in the rotor not moving for a given switch position. This
is handy for my #2 configuration above.

2. (Optionally) execute any DiSEqC switch commands on every retune of the
DVB card. This would hande the case of stubborn switches which sometimes
fail to switch on the first command (or repeat afterwards).

- Mark.

On 7/13/06, MythTV <mythtv at cvs.mythtv.org> wrote:
> #1945: DVB-S/diseqc patch
> --------------------------------+-------------------------------------------
> Reporter:  yeasah at schwide.net  |        Owner:  danielk
>      Type:  enhancement         |       Status:  new
> Priority:  minor               |    Milestone:  0.20
> Component:  dvb                 |      Version:  head
> Severity:  medium              |   Resolution:
> --------------------------------+-------------------------------------------
> Comment (by danielk):
> (In [10493]) Refs #1945. Applies modified retune patch.
> The Retune() function was using prev_tuning for retuning, but this only
> gets set when the hardware tells us the tuning has been successful. This
> adds another variable, desired_tuning, which gets set whether or not the
> tuning has been successful the first time around, and uses this for
> retuning.
> --
> Ticket URL: <http://cvs.mythtv.org/trac/ticket/1945>
> MythTV <http://www.mythtv.org/>
> MythTV
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