The OBDLink® app can log vehicle data to a CSV file automatically. If logging is enabled, the logged data can be viewed on the Files tab of the Logs screen, and it can be exported for use by an external program of your choice.
By default, logging is enabled and a CSV file is automatically created when the app is connected to the vehicle. Follow the steps in this article to change the logging settings and capture the data that you want.
Note: We recently updated the OBDLink app and made improvements to its features and how it looks. The icons on the app's home screen now have a yellow accent instead of blue (iOS) and green (Android) accents. This revised article matches the updated app’s screens and features. Download the latest version of the OBDLink app from the App Store (iOS) or Google Play (Android) to take advantage of the updated app's features and performance.
TABLE OF CONTENTS
Set up log preferences
To configure logging, tap Settings > Preferences > Logging. This screen may look different depending upon type of OBDLink adapter that you use. Each setting on this screen is described below.
| iOS | Android |
Logging Enabled
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This option enables or disables the logging feature. [Default setting is Enabled]
When logging is enabled, a new CSV log file will be created automatically each time the app connects to your vehicle.
Logging Trigger
The logging trigger configures when a frame of data is recorded to a CSV file. A single frame of data contains one data point for each sensor being logged. Tap Logging Trigger to view the options. The following options are available:
- Trigger on GPS frame [Default setting] - A frame of data is saved to file when a new GPS reading is captured from your phone or device. GPS readings are usually captured at a rate of one per second. This logging trigger is the most useful when you are using the CSV logs to view data on the Maps screen. If you are exporting the CSV files for use outside of OBDLink, then you might want to consider using one of the other logging triggers.
Note: If GPS is disabled or your device is not receiving a GPS signal, then there will be nothing to trigger the data logger and a CSV file will not be created. - Trigger on PID frame – A frame of data is saved to file when the OBDLink app refreshes each sensor being logged. For example, if vehicle speed, engine RPM, and engine load are being logged to a file, the app will read one sample of each of the three items from the vehicle, then the data will be written to the log file. This logging trigger is useful if you want to export the log files and want to have data points at the same rate as they are read from the vehicle.
Note: This option provides the fastest sampling rate. - Trigger at a fixed sample time – A frame of data is saved to file at a fixed sample time. The sample time is configurable on the Logging screen. In this trigger mode, the OBDLink app keeps track of the most up-to-date frame of data read from the vehicle. When the logging sample time expires, that frame of data is written to a CSV file. This logging trigger is most useful if you want to export the log files and want the data at a constant sample rate.
Note: If the sample time is faster than the rate at which data is read from the vehicle, you will see multiple rows in the log file with the same data points.
Logging Control
This option determines whether logging is Automatic or Manual.
- Automatic [Default setting] - Logging starts when the app connects to the vehicle.
- Manual - Logging must be started manually using one of these options:
- Navigate to Logs > Graphs and tap the Start button. For step-by-step details to do this, see the View information while driving section in this article.
- Set up a dashboard gauge using the push button style and the action to Start or Stop Logging. For step-by-step details to do this, see the Add and Edit dashboard gauges article, in the Example: Add a push button display section.
Select Items to Log
Tap Select PIDs to open a new screen and select which PIDs (such as RPM or coolant temperature) you want to record to a CSV file. [Default PIDs are vehicle speed, latitude, and longitude]
To search for a particular PID, select the PID category (such as SAE PIDs) and search within it.
If GPS is not turned on, you will be able to select GPS PIDs in this screen, however, no data will be returned.
CSV File Options
Time Format
All CSV log files contain a column with the time at which the frame was captured. The time format option determines whether the time column is written as seconds (from the start of the log) or as a full date and time stamp. [Default is Seconds]
Number of Decimals
This setting determines the number of decimal places used to write data to the CSV file. [Default is Auto]
By default, the OBDLink app enables trip logging for certain vehicle PIDs (vehicle speed, longitude, and latitude), so you can view log data even if you haven’t changed any of the options described above.
View information while driving
Note: The info presented on the Graphs tab is a separate visual representation of PIDs that you select. It allows you to view up to four PIDs while the vehicle is in motion. It is not related to the CSV file PID selections.
Before you begin, be sure to:
- Start your vehicle and connect your phone/tablet to your OBDLink adapter.
- Make sure your phone/tablet is not streaming to any other Bluetooth/BLE devices.
- Confirm that your phone/tablet is Connected to the OBDLink adapter and tap the Logs icon.
iOS Android - Be sure the Graphs tab is displayed. Tap Start (highlighted) to start logging.
Note: If the Start button is grayed out, your adapter is not connected to your vehicle. - The OBDLink app logs two items by default (vehicle speed and mass air flow rate).
Tap Menu in the upper right corner to change how the graph looks and to add new items to the graph.
- You will see the Graph Configuration screen. Scroll down to see all the options.
To add an item to the graph, tap the sample chart in the Configuration section.
Tap Add at the bottom of the screen to add an item to the graph.
In the example below, we added Engine RPM. Tap the item name to select a different PID.
The screenshots below show Vehicle speed, Mass air flow rate, and Engine RPM PIDs logged on an iOS device.
| Before logging started | After logging stopped |
View log data
By default, the OBDLink app enables logging for certain vehicle PIDs (vehicle speed, longitude, and latitude), so you can view log data even if you haven’t configured any settings.
Tap Logs in the main screen to begin.
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Graphs
This tab displays live data logging. For details, see the View information while driving section.
Files
This tab lists data logs that were captured for your vehicle (if Logging is enabled).
Tap the date and time of the trip you want to view.
You will see trip information, including start and end time, duration, distance, file size, and a map view.
Select one of these options:
- Tap Delete to delete the file. Tap OK on the confirmation message and the file will be deleted.
- Tap Open to see the actual data captured during the trip.
- Tap Share to send the CSV file to another app, such as email or a spreadsheet app.
Messages
This tab lists system log information. If you have issues connecting your adapter, the app should be recording data and it will be displayed here. If a debug log is activated, it will also be displayed here. Read more in the Create a Debug Log article.
Learn more
- The Maps function in the OBDLink app is linked to the Logs function. Read more in the Get Started with Maps article.
- You can explore other OBDLink features and functionality using our support article knowledge base.
- For descriptions of terms used in this article, see the Glossary of Acronyms and Terms.
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