maemo.org - Talk - N900 Radio Transmitter: ways to amplify the radio signal

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- Nokia N900 (https://talk.maemo.org/forumdisplay.php?f=44)

- - N900 Radio Transmitter: ways to amplify the radio signal (https://talk.maemo.org/showthread.php?t=38582)

Re: N900 Radio Transmitter: ways to amplify the radio signal

Quote:

Originally Posted by tpinhao (Post 446927)

Hello Guys

Are you sure the changing the contents of that file is going to change the Power Level ?

I think that that file is not a "config" file but it is a Log file, if you notice that file is updated whenever you start the FM Transmitter, so the only thing that that file is telling you is the current power-level.

The contents of my file where:

0

And after i started the FM Transmitter it changed to 111.

So i really think is a Log file

Maybe it cannot be changed this easily

Files in /sys and /proc are not real files -- they are special interfaces to the kernel and drivers that are exposed to act like files. writing to the power_level "file" actually sends the new value directly to the running driver which appears to then immediately send the new value to the Si4713 fm transmitter chip via the i2c bus. I can confirm through observation that there is indeed an audible pop followed by an adjustment in the ability to receive the fm signal the moment after echoing a new value to that file.

Re: N900 Radio Transmitter: ways to amplify the radio signal

pretty nice find, thanks guys .. now we just need to find out to mod the kernel driver to set the value ;)

Re: N900 Radio Transmitter: ways to amplify the radio signal

I get 113 on mine.

Rick

Re: N900 Radio Transmitter: ways to amplify the radio signal

Quote:

Originally Posted by jsharper (Post 446890)

close.

Code:

echo 118 > /sys/class/i2c-adapter/i2c-2/2-0063/power_level

Blah...my bad :P..I should use echo not cat..not sure what i was thinking when i type that mesg :)..

Thanks.

Re: N900 Radio Transmitter: ways to amplify the radio signal

does it really work ? could you explain very precisely how to do ?

thanx :)

Re: N900 Radio Transmitter: ways to amplify the radio signal

I have tested the radio transmitter in a Volvo V70, and it serves it's purpose. Compared to the old fashioned way of burning CDs I couldn't ask for more. Remember, it's a phone, not a radio station..

Re: N900 Radio Transmitter: ways to amplify the radio signal

Quote:

Originally Posted by tangs (Post 448259)

does it really work ? could you explain very precisely how to do ?

thanx :)

yes it really works - to do it - simply open a terminal, run root, type in the echo command a few posts back.

Re: N900 Radio Transmitter: ways to amplify the radio signal

and...... how to run root ?

Re: N900 Radio Transmitter: ways to amplify the radio signal

Quote:

Originally Posted by tangs (Post 448323)

and...... how to run root ?

http://wiki.maemo.org/Root_access

Re: N900 Radio Transmitter: ways to amplify the radio signal

Quote:

Originally Posted by Bratag (Post 448279)

yes it really works - to do it - simply open a terminal, run root, type in the echo command a few posts back.

Is it persistent?
Must the transmitter be powered up?