Slow OBD Update over Bluetooth

[Save The Manuals]

# RaceRender Data: TrackAddict 4.0.5a on Android 8.0.0 [samsung SM-N950U / Qualcomm Technologies	 Inc MSM8998] (Mode: -1)																									
# Vehicle App ID: 4155F4C7C05CFF7B																										
# GPS: Android; Mode: Android																										
# OBD Mode: BT (OBDLink LX); ID: "ELM327 v1.3a"																										
# OBD Settings: AP1;AF1																										
# User Settings: SL2;U0;AS1;LT0/1;EC1;VC0;VQ2;VS0;VSOIS0;VIF1																										
# Device Free Space: 196806 MB																										
Time	UTC Time	GPS_Update	GPS_Delay	Latitude	Longitude	Altitude (m)	Altitude (ft)	Speed (MPH)	Heading	Accuracy (m)	Accel X	Accel Y	Accel Z	Brake (calculated)	Barometric Pressure (PSI)	Pressure Altitude (ft)	OBD_Update	Engine Speed (RPM) *OBD	Throttle Position (%) *OBD	Engine Coolant Temp (F) *OBD	Intake Manifold Pressure (PSI) *OBD	Vehicle Speed (mph) *OBD

Hardware:
Samsung Note 8
OBDLink LX Bluetooth

Vehicle:
2004 Subaru Forester XT

Any suggestions on how to speed up my OBD update rates? I am getting updates only about 1x per second, sometimes 1.5x per second.
Logging RPM, Throttle Position, Coolant Temp, Intake Manifold Pressure, and OBD Vehicle Speed.



When I had only RPM, Vehicle Speed OBD, and Throttle Position selected, I was only getting 2 updates per second.

My smartphone is relatively new, my OBD2 adapter is the recommended one, any suggestions on what else I can try (settings?) that will improve my OBD update rate?

[Weston@HPTuners]

The OBD sample rate you'll see is usually a combination of the OBD interface device, the vehicle itself, the parameters you have selected, and the phone's bluetooth. In this case, your OBDLink LX should be quite fast (it's one of the best), and I wouldn't suspect any issue with your phone, so that leaves just the vehicle and the parameters you've selected.

For these older vehicles, especially pre-CAN, the low sample rate of around 1-2 Hz is unfortunately not surprising. I had very similar results with a 2005 Nissan 350z back when I first started developing TrackAddict. The protocols they use (VPW / PWM / ISO9141) aren't entirely the culprit, as I can set my OBD simulator to those and get higher rates than this, but the ECUs in these cars just don't seem to respond to these parameter requests very fast at all.

TrackAddict does use some performance logic here already, and less frequently updated data (such as temperatures) will be requested less often, thereby boosting the rate of other data that's expected to change often (throttle, rpm, speed, manifold pressure). Selecting fewer of those should increase the sample rate a bit, but you'll need rpm and speed for calculated gear numbers (vehicle speed is the less important one; it's only needed for gear numbers and as a backup for GPS speed), and manifold pressure for boost (starting in v4.1).

[Save The Manuals]

Weston, thank you for the explanation. That makes sense and is consistent with what I'm seeing. I will change my selections to:

RPM, Manifold Pressure, and Coolant Temp to see if that improves the update rate.

Didn't realize you were the initial developer -- thank you for making this and for investing your time supporting users like me. I truly enjoy using this software.

[Save The Manuals]

Update: I reduced the TrackAddict channels down to those three, and I'm getting 2 updates per second in the logs.

Then I hooked up the AccessPort and logged 4 channels: RPM, Boost, Throttle Position, and OBD Speed. On average I was getting 30 updates per second.

So via Bluetooth only 2 updates per second.
Via AccessPort 30 updates per second.

AccessPort log:


Could my OBDLink LX be defective? Looks like the ECU can provide much more frequent updates to the AccessPort, which rules out a slow ECU. That leaves the bottleneck to be either the BT adapter or the phone?