[Android Head-Units] kaween:
HI.

Torque itself doesn't require root. It does require Android 3.0+ or better if you're looking for a USB-OBD dongle, and even then you'd need a usb/obd with a USB-serial converter that the unit can recognize out-of-the-box. So far, I've had only succes with a USB-based OBD that has a 2303 Prolific chip inside. The issue here is : most (all ?) sellers won't be able to tell you what kind of chip drives their low-cost USB-OBD's so it's very much a guessing game.

If the seller states that he can sell you a unit which allows OBD-BT interfacing, those units will almost Always come with a BC6 Bluecore chip, which is capable of pairing itself to a generic OBD BT interface. Again, no root needed, but the radio unit must have the correct BT chip inside to make this work.

Other than that, there's the option of using a Wifi-AP-capable OBD. Here you get the same issue as with the USB versions : there are enough Wifi-based OBD's out there that only can work in AdHoc mode : such an interface is useless as Android in general isn't supporting Ad-Hoc connections since ..... 2.2 ?

So the best and easiest way to go is simply buy a unit AND the OBD BT adapter from the same seller and make sure he tells you the stuff works together. Less headache afterwards.

SWC control stand completly independant of rooting. The AN21 I've got has a simple resistive-ladder learning system, and I made my own interface board for my car that enabled the use of this protocol. If need be, a SWC adapter will be required. Sadly, I can't tell much about this as I don't know your car.

As for rooting : In my opinion, there's no _need_ for rooting the AN21, because most of the "nice stuff" is already there. You do not need some external software to enable SWC control in 3th party mediaplayers for example like you would on many other units : the support is there out-of-the-box, a bit hidden, but it's there.. Same goes for SDVC (speed dependant volume control) : already present out of the box. You can do such stuff on a RK3066/RK3188 perfectly, but to do so you'll need to install Exposed, and Exposed needs root.

Not saying rooting can't be nice to have, but my opinion is that it is perfectly possible to have a long and happy use with an AN21 without ever having rooted it.

Do however realise this unit will never see something like a Lollipop update (... I know, ever say never, but it is highly unlikely) or even much of a meaningful functionality update. In fact, all of the stuff I've seen so far were compatibility issues fixes and minor bug fixes (well, except for the very early versions that is). You pretty much buy this unit as-is and deal with it, which all-in-all isn't such a bad thing.

The Huifei-RK3066 units have a far mor vivid developer scene going on, and they'll have access to a seriously stronger cpu now (the 3188 quad), but there too, no lollipop, and I seriously doubt it will ever materialize for the 3188 as RK pushes the 3288 as Lollipop platform. Nice units, but a "I just want to insert it into my dashboard and the darn thing just has to behave with the capability of minor customisations afterwards" customer will probably be better served with an AN21-U based unit.

And then you have the Newsmy devices (also RK3188 based). Very promissing, but it nearly DEMANDS you to mod the hell out of it as out-of-the-box, it misses so many capabilities we all take for granted these days, and sadly the development has not advanced far enough to consider this unit ready for prime-time today -at least not in my opinion-. The question when or even IF that will happen, nobody can answer.