Looking for OBD connector pin out info... RPM signal
05-23-2012, 02:46 PM
#1
Pro
Thread Starter
Looking for OBD connector pin out info... RPM signal
Looking for info on the which pin I can get the RPM signal from on a '99 non-FBW 996 C2. Also which is ground?
Looking to pull as much off the OBD port as possible to route to my data logger.
Thx,
Looking to pull as much off the OBD port as possible to route to my data logger.
Thx,
05-23-2012, 03:23 PM
#2
You can't pull signals like that from OBD. OBD uses a CAN (Controller Area Network) serial communication bus. The data on the CAN bus is digitally coded (think USB, RS232, etc., you can't sniff out a unique signal without first interpreting the data). You need hardware with some type of microcontroller that has the ability to communicate via CAN, which is what OBD readers do.
For what it's worth, I design robotics for the semiconductor industry, and I use a CANopen (similar to CAN) network infrastructure for all the motion control and I/O. One machine in particular has 45 axis of motion (45 motors), and over 500 discrete digital and analog inputs and outputs, all talking to one another and being commanded via a CAN bus. A decent amount of data can be piped thru.
Edit: perhaps you can sniff the signal that is going to the tach instead? I'm not sure if the gauge cluster is one CAN node, or if each gauge is an individual node, but at some point that tach needs to get a signal that is either a digital PWM signal that you could use or an analog signal that you could use. Problem may be that that signal could be buried inside the tach, but maybe it's not, and is on one of the wires in a harness right behind the or on the cluster.
You could also get a bluetooth OBD data transmitter and get an adapter for your datalogger that can extract the data. Most of the bluetooth OBD transmitters are made for smart phones where an app decodes and displays all the info. Maybe your datalogger has a bluetooth option that is compatible with some of these OBD transmitters?
For what it's worth, I design robotics for the semiconductor industry, and I use a CANopen (similar to CAN) network infrastructure for all the motion control and I/O. One machine in particular has 45 axis of motion (45 motors), and over 500 discrete digital and analog inputs and outputs, all talking to one another and being commanded via a CAN bus. A decent amount of data can be piped thru.
Edit: perhaps you can sniff the signal that is going to the tach instead? I'm not sure if the gauge cluster is one CAN node, or if each gauge is an individual node, but at some point that tach needs to get a signal that is either a digital PWM signal that you could use or an analog signal that you could use. Problem may be that that signal could be buried inside the tach, but maybe it's not, and is on one of the wires in a harness right behind the or on the cluster.
You could also get a bluetooth OBD data transmitter and get an adapter for your datalogger that can extract the data. Most of the bluetooth OBD transmitters are made for smart phones where an app decodes and displays all the info. Maybe your datalogger has a bluetooth option that is compatible with some of these OBD transmitters?
05-23-2012, 03:23 PM
#3
Race Director
Sincerely,
Macster.
05-23-2012, 03:38 PM
#4
Rennlist Member
You might try something like this:
http://www.dealextreme.com/p/elm327-...r-dongle-16921
Bluetooth OBDII readers. Connect it to your laptop or cell phone and you can data log and view things like RPM in real time.
http://www.dealextreme.com/p/elm327-...r-dongle-16921
Bluetooth OBDII readers. Connect it to your laptop or cell phone and you can data log and view things like RPM in real time.
05-23-2012, 05:00 PM
#5
Racer
Sorry to disagree with the previous posters, but the posts above are simply incorrect.
On the 5.22. DME used in the '99 car the original poster is inquiring about there is no CAN bus other than between the tip control unit and the DME on the tiptronic cars. The later cars gradually introduced more CAN bus networks carrying more info over the paired wire system, however even the last of the 996 models still carried the tach signal to the OBD port via a dedicated wire. The tach signal is on the OBDII connector at position 9 (Violet/green wire). You can pull ground off of pin 5 (brown/blue wire).
Todd
On the 5.22. DME used in the '99 car the original poster is inquiring about there is no CAN bus other than between the tip control unit and the DME on the tiptronic cars. The later cars gradually introduced more CAN bus networks carrying more info over the paired wire system, however even the last of the 996 models still carried the tach signal to the OBD port via a dedicated wire. The tach signal is on the OBDII connector at position 9 (Violet/green wire). You can pull ground off of pin 5 (brown/blue wire).
Todd
05-23-2012, 06:29 PM
#7
The Penguin King
Rennlist Member
Rennlist Member
Sorry to disagree with the previous posters, but the posts above are simply incorrect.
On the 5.22. DME used in the '99 car the original poster is inquiring about there is no CAN bus other than between the tip control unit and the DME on the tiptronic cars. The later cars gradually introduced more CAN bus networks carrying more info over the paired wire system, however even the last of the 996 models still carried the tach signal to the OBD port via a dedicated wire. The tach signal is on the OBDII connector at position 9 (Violet/green wire). You can pull ground off of pin 5 (brown/blue wire).
Todd
On the 5.22. DME used in the '99 car the original poster is inquiring about there is no CAN bus other than between the tip control unit and the DME on the tiptronic cars. The later cars gradually introduced more CAN bus networks carrying more info over the paired wire system, however even the last of the 996 models still carried the tach signal to the OBD port via a dedicated wire. The tach signal is on the OBDII connector at position 9 (Violet/green wire). You can pull ground off of pin 5 (brown/blue wire).
Todd
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05-23-2012, 07:16 PM
#8
Race Director
Sorry to disagree with the previous posters, but the posts above are simply incorrect.
On the 5.22. DME used in the '99 car the original poster is inquiring about there is no CAN bus other than between the tip control unit and the DME on the tiptronic cars. The later cars gradually introduced more CAN bus networks carrying more info over the paired wire system, however even the last of the 996 models still carried the tach signal to the OBD port via a dedicated wire. The tach signal is on the OBDII connector at position 9 (Violet/green wire). You can pull ground off of pin 5 (brown/blue wire).
Todd
On the 5.22. DME used in the '99 car the original poster is inquiring about there is no CAN bus other than between the tip control unit and the DME on the tiptronic cars. The later cars gradually introduced more CAN bus networks carrying more info over the paired wire system, however even the last of the 996 models still carried the tach signal to the OBD port via a dedicated wire. The tach signal is on the OBDII connector at position 9 (Violet/green wire). You can pull ground off of pin 5 (brown/blue wire).
Todd
Your post prompted me to look through the wiring diagrams that I have for some Boxsters (up to '02 IIRC) and in the case of an '00 (just happened to be where the wiring diagram manual opened up) Pin 9 of the diagnostics connector (the OBD2 connector) gets a RPM signal from the instrument cluster.
Should have done this to confirm what I 'knew' before making a fool out of myself.
Thanks for posting the correct info.
Now tomorrow when I have the Boxster at the office I'll connect a break out to the connector and with a scope see if I can figure what the RPM signal looks like.
Sincerely,
Macster.
05-23-2012, 07:36 PM
#9
Whoa! Thanks Todd! I had no idea, and am really glad to be wrong in this instance! I've had some ideas of what I wanted to do with a tach signal, and now it's easy as pie to get the signal. Sweet, time to start experimenting!
05-23-2012, 07:39 PM
#11
And hey, ApexComp, is that your vid? Sweet! I really like that overlay, having tach on there too would be great.
Question, how do you sync the overlay with the video? It must all be done in real-time and not post-production, yes?
Question, how do you sync the overlay with the video? It must all be done in real-time and not post-production, yes?
06-01-2012, 12:02 PM
#13
Pro
Thread Starter
06-01-2012, 12:12 PM
#14
Race Director
No. I had to take the Boxster in for what turned out to be a bad passenger side window regulator.
I won't have the car back until later today (this afternoon) at the earliest.
I have my Turbo here to today. I'll see if I can scope its #9 pin, assuming of course the 2003 Turbo's OBD2 pins carry the same signals as the 2002 Boxster's OBD2 connector pins.
If not I'll have the Boxster at the office next Monday.
Sincerely,
Macster.
I won't have the car back until later today (this afternoon) at the earliest.
I have my Turbo here to today. I'll see if I can scope its #9 pin, assuming of course the 2003 Turbo's OBD2 pins carry the same signals as the 2002 Boxster's OBD2 connector pins.
If not I'll have the Boxster at the office next Monday.
Sincerely,
Macster.
06-01-2012, 04:00 PM
#15
Pro
Thread Starter
Pin 4 - Chassis Gnd?
Pin 5 - Signal Gnd?
Pin 9 = RPM
Pin 16 = Batt V ?
What are on pins 8, 11, 12 & 13 ?
Since data sent from the OBD port varies from vehicle to vehicle I'm not sure what the early 996 makes available.
Does anyone know which channels of data below are present on the '99 ? I may hook up a generic reader this weekend if my lazy RL approach here doesn't prove fruitful
Of everything there I really just want TPS & Lambda, both of which I can get directly anyway.
Pin 5 - Signal Gnd?
Pin 9 = RPM
Pin 16 = Batt V ?
What are on pins 8, 11, 12 & 13 ?
Since data sent from the OBD port varies from vehicle to vehicle I'm not sure what the early 996 makes available.
Does anyone know which channels of data below are present on the '99 ? I may hook up a generic reader this weekend if my lazy RL approach here doesn't prove fruitful
Of everything there I really just want TPS & Lambda, both of which I can get directly anyway.