[linux-dvb] How to turn off +5V supply on AirStar2

Klaus Schmidinger Klaus.Schmidinger at cadsoft.de
Sun Oct 8 17:54:43 CEST 2006


Klaus Schmidinger wrote:
> e9hack wrote:
>> ...
>> I think, you will found nothing about the antenna supply in the spec of
>> the demodulator (MT352) or the pll (TSA5523M). If the card has
>> implemented a switchable supply, they will use one of the GPIO-Pins
>> (GPP3 from MT352 or P0..P7 from TSA5523M). The band switch bytes for the
>> pll are 0x09 (VHF low), 0x0a (VHF high) and 0x08 (UHF). Possible, P3
>> (bit 3) is where you are searching for.
> 
> I'm afraid I don't quite understand what you mean by mentioning
> the "band switch bytes". Are you saying that in the code sequence
> 
>         if (params->frequency >= 48000000 && params->frequency <= 
> 154000000) bs = 0x09;
>         if (params->frequency >= 161000000 && params->frequency <= 
> 439000000) bs = 0x0a;
>         if (params->frequency >= 447000000 && params->frequency <= 
> 863000000) bs = 0x08;
> 
>         pllbuf[0] = 0x61;
>         pllbuf[1] = div >> 8;
>         pllbuf[2] = div & 0xff;
>         pllbuf[3] = 0xcc;
>         pllbuf[4] = bs;
> 
> in flexcop-fe-tuner.c I should do
> 
>         bs |= 0x04;
> 
> to set bit 3?

Well, or rather

         bs &= ~0x08;

to clear P3 (I guess I was off by one in my previous mail).

Klaus



More information about the linux-dvb mailing list