FS#7562 - FM Radio Quality
Opened by Terrence (terrence1019) - Wednesday, 08 August 2007, 21:58 GMT
Last edited by Bertrik Sikken (bertrik) - Sunday, 17 April 2011, 10:34 GMT
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DetailsIs there any way to increase the quality of the FM Radio tuner for the e200? My unit continually is unable to lock unto some stations, that have even strong frequencies.
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Sunday, 17 April 2011, 10:34 GMT
Reason for closing: Remind
Additional comments about closing: Probably has been fixed by now. Please let us know if it continues to be a problem.
Is it something to do with the Sanyo Radio chip being more software-based?
I definitely appreciate your efforts, Michael, for investigating this for me. Thank you very much.
When I did finish up work on the radio driver it was quite involved and I was satisfied enough that it could tune quickly and generally behave with Rockbox. Getting scanning perfect would be another whole project in itself so I just did a quick implementation that checks signal level (one that worked well enough for me in US/Canada) and left it at that for the time being with a TODO: to actually do a good implementation. None of the radio drivers really implement the scanning in any sophisticated manner and why? Because it's quite a bugger and even all the OF I've checked can barely get it right. There's also the fact on the Philips chip that what works absolutely perfectly in my region is completely ineffective in the Europe region. I doubt the situation is exactly the same with the Sanyo chip but yeah, it's quite a bit more software-driven than other ICs and the readings of the IF Sanyo suggests seem to never be quite stable nor in the tolerances given. A good deal of the code in SVN based off their suggested algorthms but modified to actually function. Nothing they said to do worked as given-- just to give an impression of what lies in wait. :)
If noone gets to it, when I'm in the mood to go back to that (and this stuff takes a mood for alot of messing around) I'll ask for testing for sure.
What FM region are you in?
But I find what you say very interesting: If the OF of some DAPs can't even get it right, but you come along and do get it right, that would be a major achievement.
From observing the IF values, I think the trick is to get them to lock on to a stable frequency.
Good work
It's just a using a newer capability of the threading and the things being done to avoid double-locking by the thread that already owned a lock were just making messy hacks like having two version of a function or using multiple locks when one will suffice. Nothing fancy. :)
Edit: I'll provide evidence that it makes no difference because next_present doesn't mute it but scanning and free-tuning do and I get no different a result.
(I think this can be achieved from the tuner logging functions. I will do the same, and we can probably compare results. Maybe the behavior is location based)