# Powering an OBD bluetooth connection



## evmetro (Apr 9, 2012)

I want to transmit data from my orion bms to a droid tablet that will be running the "Torque" app. All I have left to buy is the bluetooth adapter that goes between the obd2 diagnostic connecter and the tablet. I have my eyes on the obdlink sx http://www.scantool.net/scan-tools/obdlink-sx.html 

and obdlink scan tool http://www.scantool.net/scan-tools/smart-phone/obdlink-bluetooth.html

What I am trying to figure out is how to power the obd connection, since I have no ecm and am just wiring in a connecter out of my ICE junk heap that I pulled off the car The sx uses power from the usb connection, which I assume will have a bluetooth dongle plugged into it. The second unit listed above has the bluetooth built in and gets its power from the obd port. If this is the case does anybody know how this power is wired in on my obd port?

Does anybody have any other tips or maybe even better equipment ideas to get my data from my bms to the torque app on my droid tablet?


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## evmetro (Apr 9, 2012)

Ok, I settled on the obdlink bluetooth. The picture shows that it has a nine pin, so I can just leave out the obd cable that comes with it and plug it in directly to the nine pin that I had to wire onto the orion to plug in the can adapter for my pc. Anybody know if a pc will pair up with this as well?


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## evmetro (Apr 9, 2012)

As for the twelve volt wiring, my plan is to plug the obd cable that comes with it into an ICE vehicle and go probing with my multimeter on the nine pin end until I find power. Once I know which of the nine pins it is, I can just add that pin to the one I wired into the orions can signal. The absence of an actual obd connector seems to make a lot of sense for a car that has no ecm. I may need to do something creative to make the data available during charging. It might be nice to check out how my charge is doing from my phone instead of going out to the garage.


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## frodus (Apr 12, 2008)

Don't recreate the wheel, the pinouts are readily available online.
http://www.scantool.net/accessories/accessories-cables/j1962m-to-db9f-type-b-cable.html
and this:
http://www.obdstore.com/wp-content/uploads/2011/09/obd2_cable_pinout.png

I've verified that both are the same cable, which is what comes with your adapter. You need to wire as follows:
CANH(orion) to the DB9 pin 3
CANL(orion) to the DB9 pin 5
+12V to the DB9 pin 9
Common (12V negative) to the DB9 pin 1

For +12V, use the same 12V as the Orion incoming power.



And as far as the PC, you should be able to if the PC has bluetooth. Just pair, install some OBD software, and make sure the software is going to the correct serial port.


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## evmetro (Apr 9, 2012)

Frodus, thanks for the reply. Great info. It looks like I will need to wire in a relay to switch between charge power and ready power to be able to see stuff from remotely while charging. Bluetooth is new to me... does it sound right that I could use this single bluetooth device plugged directly into the nine pin that I wired to the orion in place of the can adapter as well as for displaying data to multiple android devices simultaneously? I am considering loading torque on a couple of old smartphones so that I can have more gauges displayed besides my samsung tablet that will be my primary instrument cluster.


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## frodus (Apr 12, 2008)

evmetro said:


> Frodus, thanks for the reply. Great info.


 No problem.... all I did was "google".



> It looks like I will need to wire in a relay to switch between charge power and ready power to be able to see stuff from remotely while charging.


Depends on how you want to use it. It just needs power whenever you want to communicate. A relay could work, but you need to make sure it doesn't interfere with power/enable going to the Orion.



> Bluetooth is new to me... does it sound right that I could use this single bluetooth device plugged directly into the nine pin that I wired to the orion in place of the can adapter as well as for displaying data to multiple android devices simultaneously? I am considering loading torque on a couple of old smartphones so that I can have more gauges displayed besides my samsung tablet that will be my primary instrument cluster.


Nope. One bluetooth OBD adapter per tablet. You can have one tablet connected to several Bluetooth devices (a headset, bluetooth headphones, OBD adapter), but a single bluetooth OBD adapter will only connect to one device. This is a limitation of Bluetooth, not torque or android.

If you want more than one tablet, you'll need to add another bluetooth adapter, and set it up to talk to the second device.


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## evmetro (Apr 9, 2012)

That is disappointing that the bluetooth does not transmit to multi devices simultaneously. I have not educated myself yet on the in and outs of the can circuits yet, but I saw the section in the orions wiring instructions about having to install 120 ohm resistors on the other can lead if I want to add something to that line. Do I need to further educate myself on this, or can one add another bluetooth output and wire it parallel with the first one? I am currently using the line that has the resistor inside the orion....


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## jeffcoat (Apr 16, 2012)

You should have no problem wiring a second bluetooth adapter in parallel with the first one; just be sure that the resistor goes at the end of the longest run.

In our conversion we leave the bluetooth adapter powered all the time; it has not run down our 12v lawn tractor battery even after sitting for several days. You may want to measure the current draw of your adapter to see if it is similarly low.


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## frodus (Apr 12, 2008)

Bluetooth is a single host system.... and so are the Ad-hoc Wifi OBD2 dongles I've seen. There's really no reason to have multiple devices connecting to one device.

The network should look like this. You can add many nodes and could wire it such that you keep your CAN converter AND the OBD-2 Bluetooth device on the same network. Just tap off exactly like node 1. Just do not STAR from one point. It has to be along the same line, in a daisy chain. If you don't know what that is, google it.









As long as you have the Orion on one side (not sure if it has a 120ohm resistor inside, or if it's external) and another 120ohm at the last device, you're good. There has to be a termination on both ends. Orion has one, and the last device has the other. The Bluetooth dongles DO NOT have the 120ohm resistor in them, but the can dongle may.


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