Rockboxed Sansa M240V4..Issues but seems close..

[cpnfantstk]

I am one of the few  people who have actually installed rockbox on the M240V4.  I know it is unsupported and considered unusable because of its playback crashing and low volume. I would like to help in some way to at least get playback stable. I have no dev or code experience but I can test the unit when patches or new builds are created and report bugs.

 I know there is few that have interest in this particular unit but considering that menu navigation, the radio , and playback of the codecs I tried (flac,mp3 @ low volume, high volume crashes unit) work, it seems worth it to get the m200v4 series a stable release.

Any suggestions on how I can contribute would be appreciated. Thanks to Funman and others for whats been done so far.
 I

[funman]

I think it's a pretty good occasion to jump on the boat and get a coding/dev experience.

So the only suggestion which comes to my mind is : learn about C and start looking in the code

[pixelma]

cpnfantstk:

Maybe you can also find other people with an Sansa m200 interested in improving the port. If you e.g. know a forum or something you could try and gather some interest?

[saratoga]

Whats the highest volume it can do without crashing?  Does it always crash at the same level?

[cpnfantstk]

The volume level I can reach is -8db without the unit shutting down and yes Saratoga always at the same level. However, the volume is fairly low for that setting . Its audible but quite low. I am using the 6/12/09 build (r23879). I have tried newer builds such as may15th/10 and a build from a few days ago but the screen is not shown fully. Only one line and its hard to navigate that way. Regardless of the build I have used , the screen view is not optimal(but better with the older r23879). Some things are cut off or as I mentioned only one line.  USB is working fine now with the newer builds ( no holding the left button).

Kind of wonder why the clip does not have the same issue with playback since I read here that M200v4 and Clip is virtually the same except for cosmetic differences. If there is anything else I can report. Let me know.
 

[saratoga]

The m200 uses a AA battery, while the clip uses a 3.7v lipoly battery.  The voltage regulators need different settings.  Presumably whatever settings we're using for the m200 are insufficient to power the headphone amp at full volume.

[funman]

Can you give a try to this patch http://pastie.org/1026749 ?

I am not sure if the second part is effective, but perhaps the 1st part should solve the quiet audio problem.

[saratoga]

Whats the reasoning behind this:

Code: [Select]

+#if (CONFIG_CPU == AS3525 && !defined(SANSA_M200V4))
...

I think if the regulators are setup right they should provide more then enough current to drive the headphones the same as on the other AMS devices.  The problem is probably just that we're running them out of spec now, so when the amp tries to output too high a voltage it sags the CPU voltage too low and the system powers down.

[saratoga]

The volume level I can reach is -8db without the unit shutting down and yes Saratoga always at the same level.

Just wondering, is this with a 1.5v (alkaline) or a 1.2v  (NiMH) battery?

[funman]

Whats the reasoning behind this:

Code: [Select]

+#if (CONFIG_CPU == AS3525 && !defined(SANSA_M200V4))
...

I just spotted that this bit differs between clipv1 and m200v4 at OF init but perhaps it's changed in further code

[cpnfantstk]

The volume level I can reach is -8db without the unit shutting down and yes Saratoga always at the same level.

Just wondering, is this with a 1.5v (alkaline) or a 1.2v  (NiMH) battery?

I am using an energizer alkaline 1.5v.  I will try your patch Funman. How to apply it though?

[saratoga]

http://www.rockbox.org/wiki/WorkingWithPatches

[funman]

If you can come on irc, trying different patches could be much faster than using the forum

[cpnfantstk]

If you can come on irc, trying different patches could be much faster than using the forum

I would definitely like to do that. I just need to familiarize myself with how to apply patches with Cygwin. Once I apply my first patch (the one you gave above) successfully, I can then come on IRC and try different ones.

If there is an easier way to apply a .diff patch then I am all for it. . Thanks.