[Android Head-Units] kaween:
[MENTION=2334287]Malcez[/MENTION] :

Heh. spoken like a true tweaker. And I understand, respect and recognize your point of view. :)

And actually this is a real reason to engage a potentially interesting discussion if you're willing. I'm Always eager to learn, and discussions tend to be the best way to do so.

Here on this forum, I walk a cautious path : the're enough people looking her not only for answers, but for _Assurances_. So when somebody asks me "is it possible to brick my unit with a bad MCU", there's no way to say "no, definitly not" because I simply can't exclude the possibility, though when done correctly the chance of bricking is remote. Sure, everybody does what they do on their own responsibility and that should be understood, but that wouldn't change me feeling bad if somebody would follow a piece of advice I'd given and ended up with a defective unit.

I have a repaired spare unit which I use to experiment on.

I think most people here do not. If I mess up my spare unit, sad, but not a real problem, and it remains MY problem.

Hence I'm a lot more careful on this forum regarding other peoples' questions than I am for my own unit and Always take a "worst case scenario" approach.

From that viewpoint it is my opinion that unless a true technical reason is present, updating the MCU is moot and invites unnecessary risk unless there's a valid reason to do so.

So the question should rather be : where is the advantage of updating the MCU providing your current one works correctly ?

Basically, the MCU is "your radio motherboard exclusive the ARM board", and the "real mcu" is the little part of programmable logic that arbiters what goes on there.

There's a bit of unclarity here : most sellers will refer to the "mcu" as the complete mainboard of the unit, but in the true sense of the word it is only a 5x5mm ST/Thompson chip that resides on that mainboard.

It is however "the only programmable bit" there if you exclude the ARM processor board itself.

There's little to no reason to update this : the FM tuner part sitting there for example is not programmable in a true sense of the word. You can't make the unit sound "better" as the mcu just steers the Rohm into the right direction, but you can make it worse by installing a wrong mcu which doesn't command the specific hardware version in your unit, but again the Rohm itself also is not programmable : it is basically "just" an analogue switcher which routes the correct streams to the amp in function of what is needed. Depending on version of Rohm, it may be equiped with a various number of bandfilters, possibly a DSP for sound effects, but that's it. The chip itself is pretty much fully hardwired and does permit "wrong command steering" resulting in odd problems with switching, wrong EQ settings and whatever when a wrong mcu version is installed, but you can not reprogram the chips' filters for example to "get better frequency response" or whatever.

Same is true for the BT board.

So what remains is the question : other then fullfillement of personal curiosity (which is a powerful and valid reason !), "Why" ? (providing the unit worked correctly prior to mcu upgrade and it still does after updating a system version to a newer one). Knowing what is and what isn't possible by updating the mcu, what gain does one possibly hope for ? The main reason for the programmable mcu is to allow the manufacturer a great liberty in terms of usable hardwareversions, chipversions and appearances in terms of buttons, layout, ect. But once in place and working correctly, I fail to see the need to mess with it (.... other then personal interest, as said).

Addendum : I see you have issues with bad FM reception in a VW. This is a complaint that returns on nearly every android-2din thread when using a VW car. For the life of it, I can't remeber in what subforum I've read this (I think it was the Huifei ...) where one forum member discovered that the antenna connector used to connect the *2* diversity antenna's which VW tends to use on a regular base go inside a sort of Y-adapter, which then again feeds back into the RF-input of the unit. After opening that Y-type antenna connector, he discovered that the Y-connector just uses ONE of the two Original antenna's, the second is simply discarded and "dies on the PCB" leading nowhere.

A (more expensive) fully connected adapter should provide a much better result. No idea if this applies to your situation, just a friendly heads-up.