R820T Tuner IC I2C commands

[rfdave]

Hello,

Not sure if this is the place to post this but I'm looking for help with the Rafael R820T ic. Specifically with the I2C commands to control frequency tuning of this tuner ic. I have tried to contact Rafael with no response. Is there anyone here who has any information on what I2C commands are used to control this ic?

Here is a brief description of what I'm trying to accomplish. I have a DVB-T receiver that I am using to receive and decode MPEG4 video and audio from a DVB-T transmitter. Unfortunately all of the receivers I have found only have preset channel selections on specific frequencies and BW. I want to connect a I2C bus directly to the R820T ic and use a micro controller to make the DVB-T receiver frequency agile so it cam be tuned to any frequency I choose. I need to make the receiver completely independent to any outside control from a pc and SDR software.

Any help to finding this information would be greatly appreciated.

Thanks for your time.
Dave.

[rtlsdrblog]

This is a bit more complicated than what most discussion on this forum is about. Also, I don't think Rafael would reply to you as I think the tuner information is actually under NDA.

You could try look through the reverse engineered rtl-sdr driver code on the Osmocom website, or ask on their mailing list for help.

[LB6MI]

Well..

1. There are leaked datasheets/reverse engineering notes/linux drivers around the web with some details.

2. Frequency change is by setting up a sigma-delta PLL frequency synthisizer, you can find plenty examples of similar parts around the web.

3. AirSpy actually have a fairly simple(compared to the others) opensource driver if you want something to look at!

Still:
If you are ok with quadrature output, there are actuallty parts with open datasheets avaiable!