OBDMPG - MPG OBDII Plugin for RR [NEW! 6-12-09]

mezz64 · 09-03-2008, 07:32 PM

After seeing a few requests for some interface between RR and OBDII via an ELM327 interface I decided it was about time for me to release my current progress on my MPG plugin.

The plugin uses the ELM327 VB6 class posted on these boards a while back by member Erorus to communicate to the vehicle. Without it I'd be nowhere.

Installation is achieved via an easy to use installer courtesy of mitchjs that can be downloaded below. The only file that needs modified for operation is the obdmpg.ini file located in the plugin folder.

There is a .ini file that stores current data on hibernate/standby/shutdown as well as defines some variables:

COM Port #
Baud Rate
Engine size in Liters
Volumetric Efficiency (VE), This isnt required if you have a MAF, if you don't the 75-90 range works for most 4-cycl vehicles
Gas Tank size in gallons or liters

All Versions can be downloaded here:
Updated! 06-12-2009
Latest Version: 1.4.1
Sample skin files are now included in the installer and should be copied into an existing Carwings installation.
http://rr.johnmihalic.com

Skin Commands Text File:
Updated! 12-18-2008
http://www.johnmihalic.com/obdmpg/skin_commands.txt

Please reply with any questions or problems, I'll reply the best I can!

This plugin is available free of charge and will always remain that way, however if you would like to thank me for my effort feel free to donate via the button below. Make sure to include your username so I can acknowledge you. Thanks!

Thanks To All Donors!
agiorgitis - $5

Screen shots of Carwings implementation:

pcpete · 09-04-2008, 09:50 PM

Thx for this!!
Definately something I've been looking for...

I'll give it a try once I get a chance..

tolisn · 09-05-2008, 04:55 PM

I would surely love this plugin to evolve into something more that mpg. Thank you for posting it here. Maybe this will be a start to a very good OBDII plugin for our favorite front end.

mezz64 · 09-05-2008, 06:32 PM

As I've mentioned before it's not at all difficult to adjust the plugin to spew out the value from any PID. I just don't know how to do anything but display the value in a label in RR.

Let me know which PIDS you are interested in displaying and I will add the options to the plugin.

tolisn · 09-06-2008, 03:37 AM

Hi.
There are not that many standard PID's that you can insert as you can see here
http://en.wikipedia.org/wiki/OBD-II_PIDs.

Displaying the value is all that is needed for a start.
How about inserting as many PIDs as you can and letting the user decide which ones he requires to display in a RR skin? This way you will not be receiving contiious requests for more PIDs.
Will you be also making a button for clearing the CEL (check engine light)? This is also one PID.

Thanks for your effort.

mezz64 · 09-06-2008, 02:56 PM

I'll add a bunch of the standard ones and include True/False enable statements for them in the config. Should have something posted up by the end of the day.

I have no idea how to do the clear CEL. I don't think the elm327 class i'm using is setup to do that.

tolisn · 09-06-2008, 03:08 PM

I think the the clear CEL PID is issued like any other PID. When you issue a PID to the OBD port the ECU decides if it should report back a value or not. The standard PIDs are sent to the ECU and the ECU upon receiving them sends back a value for that PID.
I think that if you send the PID for the clear CEL and the ECU sees it it will simply clear all the codes and turn off the CEL. I could be wrong though.
Anyone else have some info about this ?

mezz64 · 09-06-2008, 04:20 PM

Link in first post is updated with the latest build. I've included support for the following PIDs. Make sure "ExtraOBD=True" is set in the config file to see them.

PID 05 - Engine Coolant Temp - Skin "ect"
PID 06 - Short Term Fuel % Trim Bank 1 - Skin "stft1"
PID 07 - Long Term Fuel % Trim Bank 1 - Skin "ltft1"
PID 08 - Short Term Fuel % Trim Bank 2 - Skin "stft2"
PID 09 - Long Term Fuel % Trim Bank 2 - Skin "ltft2"
PID 0A - Fuel Pressure - Skin "fp"
PID 0B - Intake Manifold Pressure - Skin "map"
PID 0C - Engine RPM - Skin "rpm"
PID 0D - Vehicle Speed - Skin "vss"
PID 0F - Intake Air Temp - Skin "iat"
PID 10 - MAF air flow rate - Skin "maf"
PID 11 - Throttle Position % - Skin "tp"
PID 22 - Fuel Rail Pressure - Skin "frp"
PID 45 - Relative Throttle Position - Skin "rtp"

The display of these won't affect the MPG functions as that is still the primary purpose of this plugin at the moment.

It seems as if the Clear CEL command is set in mode 4 but there isn't a PID listed on the wikipedia article to send. If anybody has any ideas i'd be happy to try and implement it, just not sure how.

Enforcer · 09-06-2008, 04:42 PM

I would suggest that you prefix your labels with something to indicate they come from your plugin, incase someone has or will use the same label names.

ie

obd_ect
obd_stft1
obd_ltft1

etc.

h3rk · 09-06-2008, 04:55 PM

when you request for vss, the software sends (some time after the initializing AT stuff and the initial 0100\r) 010D\r ; which is "set mode 1", "Send PID 0D", (and process the response).

Wouldn't it be a more simplistic, 04\r ; which is "set mode 4", (and send nothing else), (and nothing to process)? And that's it (PID's being only an aspect of mode 1 and maybe 9)?

I thought of it more as it CEL Clear is done by setting mode 4, rather than it being set within mode 4.

I'm just learning this stuff though.

tolisn · 09-07-2008, 06:24 AM

take a look at this. maybe it will help.

mezz64 · 09-07-2008, 01:15 PM

Quote: Originally Posted by Enforcer

I would suggest that you prefix your labels with something to indicate they come from your plugin, incase someone has or will use the same label names.

ie

obd_ect
obd_stft1
obd_ltft1

etc.

Good idea, i'll get this fixed asap.

Quote: Originally Posted by tolisn

take a look at this. maybe it will help.

That was helpful. Looks like clear CEL requires mode 4, PID 00, and a 4-byte response. Should be no problem to implement. I have no way to test it however.