[ale] need 5" android tablet / phone for obd car instrumentation

[Ron Frazier (ALE)]

On 9/17/2013 12:03 AM, Alex Carver wrote:
> On 9/16/2013 18:44, Ron Frazier (ALE) wrote:
>
>> I guess a bluetooth adapter would be ok if it shuts off within minutes
>> or seconds after the car is turned off.  I don't want anyone hacking
>> into my engine while I'm in a parking lot though.  A guy at an auto
>> parts store told me more advanced obd scanners can unlock the doors, 
>> etc.
>
> So wire it that way.  You just need a relay connected to (or draw 
> power for the dongle from) the ignition switch or some other 
> hot-when-running wire.  If the car isn't running, the dongle is off.  
> For that matter you could just wire a mechanical switch to turn the 
> thing off.
>
> It is only possible to unlock doors or do other functions if the OBD 
> connector bus is attached to the same bus controlling the locks.  Some 
> manufacturers did link subsystems together via the OBD or CAN buses 
> which would allow such a hack.  Others did not.
>

By default, the obd port always has power and the bluetooth adapter gets 
its power from that.  I could switch the power circuit as you suggest by 
building a custom obd jumper cable.  A better solution would be to have 
an adapter that has an auto shut off feature, or to use a wired solution 
with no wireless at all.  Up to this point, I've been removing the 
bluetooth adapter from the obd port every time I exit the car.  Other 
than being awkward, I'm concerned that this could wear out the obd plug 
in the car.  I don't think they're designed to be plugged and unplugged 
multiple times per day for months or years.

Ron


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Ron Frazier
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