Thread: obd2 to USB cable + Android Tablet

there is an application called torque i would try, it still uses a bluetooth protocal but has alot more extensive features and is a really great app. i dont know of any direct wired OBD2 units for android right now.

Originally Posted by zr2ee

there is an application called torque i would try, it still uses a bluetooth protocal but has alot more extensive features and is a really great app. i dont know of any direct wired OBD2 units for android right now.

So torque, or possibly a more expensive, better application would have a more responsive bluetooth interface?

-Bob The Savage

I thought those things were wifi not bluetooth?

Edit from REV faq:

Why don't you support USB or Bluetooth OBD-II interface hardware?


We have investigated the hardware integration features of iOS 4.x. However, after confidential discussions with Apple, we have concluded that WiFi is still the most reasonable option at this moment—both from technical and business perspectives.

We will not be supporting Bluetooth or Dock Connector OBD II connections yet—but we continue to persue this option and will announce any updates as soon as we have them.

Maybe latency is one of the issues with BT.

Torque has a free and a paid version and can work on either wifi or bluetooth, i think it needs to be rooted to work with wifi though. anyways it would be worth trying out.

bluetooth should be plenty fast enough for obd-ii (and for CAN). Bluetooth 2.0 should support up to 2.1Mbit transfer rates. What scantool do you have and what phone?

Some android tablets have usb host capability, but maybe not all. Make sure the one you want supports usb host. Also, I'm not sure that android's kernel has support built in for ftdi, which is the serial -> usb chip most scantool seem to use. Maybe there is a module available, maybe not. Maybe there is a userspace driver too... maybe not. You'll have to check and see. Android probably wasn't designed to have usb-host capability until recently so they may have disabled support for a number of usb devices that would normally work in Linux.

Also the obd-ii app has to be smart enough to use a common serial device instead of a rfcomm/bluetooth device. You need to make sure your software also supports that.

OBD2 is a bit stupid. It gives all the answers to all the questions asked. So if you ask a lot of questions (PID's) it will be busy replying all of them. If you want to speed it up, make sure you only ask fewer PID's at a time.

Take a screen with only one PID, speed for example. You will see it is fast enough.

Or use Mobilscan adapter and app ;-)

Yes Blutooth is not the bottle neck, it is exactly how much you ask OBDII for, in general it will answer 5 times per sec (depending on the car), and even thought that sounds fast enough if the app ask for everything (all sensors) it will take something like 5 sec to get all done.

But when just taking one (or 3 ) values then it will be fast enough for most purposes.

N

Interesting. So i guess the USB is plausible, but for someone with only a rudimentary understanding of android and its more obscure workings, it may be difficult for me to get something so unsupported to work.

I'm interested in the comments about Bluetooth not being the bottleneck too. Looking back I should have spent way more time playing with settings and before declaring the idea bust.

I think I'll order another kiwi Bluetooth adapter now and test way more thoroughly.

-Bob The Savage

Or a Mobilscan, just tested it on a Galaxy tablet it works perfectly