[linux-dvb] TT-Budget C-1501

Hartmut Hackmann hartmut.hackmann at t-online.de
Tue Apr 22 22:49:37 CEST 2008


hi,

e9hack schrieb:
> Sigmund Augdal schrieb:
>> tor, 17.04.2008 kl. 23.31 +0200, skrev Hartmut Hackmann:
>> <snip>
>>> Do you have a datasheet of the tda10023? From the first glance, i have the
>>> impression that it was only used with a conventional tuner yet. With the
>>> silicon tuner, the chip needs to be programmed to use a different IF. We
>>> beed to find out how this is done.
>> I don't have any datasheet. I tried playing around with some of the
>> values in the init-tab, and they do affect the signal levels (signal and
>> snr) reported, but I haven't managed to find something that does give a
>> lock. There is also a if_freq variable in the current driver sources
>> that does not seem to be passed to the chip directly but is used in some
>> computations. In the current driver this value is selected based on
>> channel bandwidth (being only used for dvb-t this far). I've tried with
>> several values for this (8MHz, 0MHz, 4MHz and the currently used 5MHz
>> for 8MHz bandwidth channels).
>>
>> Birr: Do you have any info on this, as you seem to be the last developer
>> working on that demod?
> 
> I don't own the datasheet of the TDA10023. I think you must read the configuration of the 
> TDA10023 from windows. This can be done with this program 
> (http://linuxtv.org/downloads/saa7146dump-0.2.zip). If it is necessary to monitor the 
> initialization of the tuner chip, you must use an i2c-monitor. I developed a cheap monitor 
> (http://www.vdr-portal.de/board/thread.php?postid=639818#post639818). The costs of the 
> parts are less then 10€. To build such a monitor, you should know what a soldering-iron is.
> 
> -Hartmut Birr
> 
Looks like we need to make changes in both, tda827x and tda10023. Currently the 10023
is programmed for 36.13MHz IF frequency. This is *not* possible with the 827x.
So we need to implement a configuration option for the tda10023 to select the IF center
frequency (haven't had the time to have a close look yet) and we need to implement a way
to let the tda827x driver choose the right parameter set.
I would be more interested in the configuration of the tda10023. With the tda827x, i know
what to do.

Hartmut




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