Because my 2005 Jeep Liberty does not have a MAF sensor, it of course can not provide an MAF reading. Instead I have a MAP, with which it is significantly more difficult to estimate instantaneous MPG. Without MPG, the coolest graph produced by obd2kml doesn't have proper coloration.

I decided to look into other cool visualizations I can make. I found the relevant code in /src/kml/obdgpskml.c. There are currently three graphs, by which I mean a layer in the final KML file:

* MPG, Speed & Position
* RPM & Position
* Gear & Position

To be clear, without a MAF sensor, there is no data to calculate MPG. When that graph is generated, the result is an informative error message and the graph is not generated.

In this thread I hope to determine and implement a small set of ideal KML layers to show off road trip data. My vehicle supports the following PIDs:

01: Monitor status since DTCs cleared
03: Fuel system 1 and 2 status
04: Calculated LOAD Value
05: Engine Coolant Temperature
06: Short Term Fuel Trim - Bank 1
07: Long Term Fuel Trim - Bank 1
08: Short Term Fuel Trim - Bank 2
09: Long Term Fuel Trim - Bank 2
0B: Intake Manifold Absolute Pressure
0C: Engine RPM
0D: Vehicle Speed Sensor
0E: Ignition Timing Advance for #1 Cylinder
0F: Intake Air Temperature
11: Absolute Throttle Position
13: Location of Oxygen Sensors
14: Bank 1 - Sensor 1/Bank 1 - Sensor 1 Oxygen Sensor Output Voltage / Short Term Fuel Trim
15: Bank 1 - Sensor 2/Bank 1 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim
18: Bank 2 - Sensor 1/Bank 3 - Sensor 1 Oxygen Sensor Output Voltage / Short Term Fuel Trim
19: Bank 2 - Sensor 2/Bank 3 - Sensor 2 Oxygen Sensor Output Voltage / Short Term Fuel Trim
1C: OBD requirements to which vehicle is designed
20: PIDs supported 21-40
21: Distance Travelled While MIL is Activated
I am going to start with one that I think makes sense: speed on the height axis and RPM on the color axis. I'm also interested in one for the fuel system: perhaps fuel tank level on the height access and fuel trim (which is a measure of how much is squirting into the cylinders) on the color axis.

I modified the code in /src/kml/obdgpskml.c to produce the speed-RPM-position graph. I cannot attach it to this post because I'm having trouble uploading it.

Is there a way so that when it opens in Google Earth it will zoom straight to the trip data? I have to actually zoom down to Juneau, Alaska.

Does anybody have any other good ideas for how to visualize this data? What other graphs would be interesting? Does anyone know how to provide annotation to the KML? Like, what if we had a utility called "obdgpsnote" which allowed you to type in something like "got gas $35.56 11.21 gallons" then have that appear as a notation in the KML? Does anyone know how to put in photograph links? It would be really great to do that.