[Q] eee transformer in car (searching for pinout, tips, bluetooth headset router, ..)

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fpdragon

Senior Member
Sep 9, 2008
132
8
hi!

I just ordered an asus eee tab transformer for my car, as car entertainment system and navigation system. I am planing to invest some time o modify the hardware of the car to fit the tab optimately in.

One thing I'd like to do is to let the car command the tab for boot and shutdown. I am thinking of using the asus docking station interface of the tab but I have no pinout of this connector at the moment. Can anybody help here?
Maybe it is also possible to throw typical "next", "back", "play", "stop", ... commands? I am expecting an serial interface or something similar. Since I am an routined embedded developer, with a pinout this should be no problem.

The second thing is maybe a software thing.
I have an bluetooth car radio which supports one connection at the same time. The Idea was to use the Tab with bluetooth a2dp but with this connection all calls on my bluetooth phone are ignored. Is there something to establish a android to android bluetooth connection where the tap plays the roll of a bluetooth a2dp headset.
So for music and navigation:
Tab <-> CarRadio
For phone calls:
Phone <-> Tab <-> CarRadio
The other thing is, can the android tablet keep 2 bluetooth connections at the same time from the hardware point of view?

Ok, I think I wrote enough for now ^^
Hope somebody can help with any information.
 

tonyz3

Senior Member
hi!

I just ordered an asus eee tab transformer for my car, as car entertainment system and navigation system. I am planing to invest some time o modify the hardware of the car to fit the tab optimately in.

One thing I'd like to do is to let the car command the tab for boot and shutdown. I am thinking of using the asus docking station interface of the tab but I have no pinout of this connector at the moment. Can anybody help here?
Maybe it is also possible to throw typical "next", "back", "play", "stop", ... commands? I am expecting an serial interface or something similar. Since I am an routined embedded developer, with a pinout this should be no problem.

The second thing is maybe a software thing.
I have an bluetooth car radio which supports one connection at the same time. The Idea was to use the Tab with bluetooth a2dp but with this connection all calls on my bluetooth phone are ignored. Is there something to establish a android to android bluetooth connection where the tap plays the roll of a bluetooth a2dp headset.
So for music and navigation:
Tab <-> CarRadio
For phone calls:
Phone <-> Tab <-> CarRadio
The other thing is, can the android tablet keep 2 bluetooth connections at the same time from the hardware point of view?

Ok, I think I wrote enough for now ^^
Hope somebody can help with any information.


Something to consider when designing.
Not sure if this is going to be a permanent install or not. But you can easily set up your audio through the Hdmi instead of burning battery with your Bluetooth. At least you can still use your phone through the Bluetooth. You can also incorporate other monitors in other parts of the car. I was speaking to a car audio shop for this type of install myself a few weeks ago. I will try to get more details and report back. Was waiting for the desktop docking station to come out to really run with it.:cool:
 

fpdragon

Senior Member
Sep 9, 2008
132
8
Something to consider when designing.
Not sure if this is going to be a permanent install or not. But you can easily set up your audio through the Hdmi instead of burning battery with your Bluetooth. At least you can still use your phone through the Bluetooth. You can also incorporate other monitors in other parts of the car. I was speaking to a car audio shop for this type of install myself a few weeks ago. I will try to get more details and report back. Was waiting for the desktop docking station to come out to really run with it.:cool:

Thanks...
Bluetooth battery burn would be no problem since I want to load the battery over the car. Anyway... I'm afraid that there won't be something like a "bluetooth router" so I have to use the analog audio out. That brings me to my first question: I need the pinout of the asus connector to control the tab over the steering wheel control.
 

maxpower47

Retired Recognized Developer
Jul 23, 2010
123
1,435
Indianapolis
code.google.com
I don't think anyone's figured out a pinout yet, and even if they do, it wont be as simple as "this contact is for play, this one is for skip, etc". All those most likely go through a usb interface. Not that that would be impossible, but if you're using bluetooth your headunit should support AVRCP for sending those commands over bluetooth. Most android devices only support 1.0 right now, but that still gives you play/pause, stop, next, previous, maybe ff and rewind too.
 

Narog

Member
Jul 30, 2011
12
0
Silkeborg
As an embedded developer here follows one idea that maybe can help you.

Why not using all via BT, I will say you prob looking for some BT support inside the kernel. If you find a similar application using linux (google it), maybe you can ported it to the transformer. Compiling the kernel with new drivers is very easy, then u just need to get into the software part.

Have fun.
 

fpdragon

Senior Member
Sep 9, 2008
132
8
As an embedded developer here follows one idea that maybe can help you.

Why not using all via BT, I will say you prob looking for some BT support inside the kernel. If you find a similar application using linux (google it), maybe you can ported it to the transformer. Compiling the kernel with new drivers is very easy, then u just need to get into the software part.

Have fun.

Thanks for your post!

I was thinking about a similar idea. Bluetooth could be an alternative but with bluetooth it won't be possible to switch the device on. So I tried to find a pinout and maybe I have luck to command a power on. Anyway... Right now BT seems the more realistic way, you're right.
 

maxpower47

Retired Recognized Developer
Jul 23, 2010
123
1,435
Indianapolis
code.google.com
As an embedded developer here follows one idea that maybe can help you.

Why not using all via BT, I will say you prob looking for some BT support inside the kernel. If you find a similar application using linux (google it), maybe you can ported it to the transformer. Compiling the kernel with new drivers is very easy, then u just need to get into the software part.

Have fun.

Android and the TF already support A2DP audio streaming and AVRCP remote control over bluetooth, there's nothing that needs to be done here. I'm pretty sure its only AVRCP 1.0 though, which only supports the basic controls (play, pause, stop, next, previous, etc). The newer versions also do things like metadata, so you can see on your headunit what song is playing.

I can say from experience that working with improving BT support in android is not easy after I spent a fair amount of time banging my head against the wall trying to add MAP support to CM7. In any case, without HC source it would be impossible to do here anyway.
 

maxpower47

Retired Recognized Developer
Jul 23, 2010
123
1,435
Indianapolis
code.google.com
Thanks for your post!

I was thinking about a similar idea. Bluetooth could be an alternative but with bluetooth it won't be possible to switch the device on. So I tried to find a pinout and maybe I have luck to command a power on. Anyway... Right now BT seems the more realistic way, you're right.

I'd bet that there's no way to power it up over the dock connector since the keyboard dock doesn't support it.
 

captmiddy

Senior Member
Aug 30, 2010
68
16
I'd bet that there's no way to power it up over the dock connector since the keyboard dock doesn't support it.

Power it up maybe not, but wake it up certainly. If you allow the unit to be in deep sleep when you open the dock it wakes the unit. And as long as you are constantly feeding a small amount of power to it to keep it fully charged it shouldn't be a big deal. Maybe tear down a dock to provide an extra battery to the unit and perhaps the circuitry you need for wake on start of the car. I don't play with hardware so not sure what this would do but it seems it should be possible since it already does this to an extent.
 

fpdragon

Senior Member
Sep 9, 2008
132
8
Power it up maybe not, but wake it up certainly. If you allow the unit to be in deep sleep when you open the dock it wakes the unit. And as long as you are constantly feeding a small amount of power to it to keep it fully charged it shouldn't be a big deal. Maybe tear down a dock to provide an extra battery to the unit and perhaps the circuitry you need for wake on start of the car. I don't play with hardware so not sure what this would do but it seems it should be possible since it already does this to an extent.


Thanks Tor Your post...
Im Not sure hat this "deep sleep" is. is this the same like when i press the power button shortly on the tab or another power mode?
I have no dock and I wanted to save my money and not buy it.