Log Command

View robot logs with FTC-relevant filtering.

Usage

/log                    # View recent logs
/log -f                 # Follow logs in real-time
/log --errors           # Show only errors
/log --filter TeamCode  # Filter by tag
/log --clear            # Clear log buffer first

Arguments

Argument	Description
-f, --follow	Continuous output (like tail -f)
--errors	Show only errors and exceptions
--filter <tag>	Filter to specific tag (e.g., TeamCode, RobotCore)
--clear	Clear log buffer before reading
--since <time>	Show logs from last N minutes (e.g., --since 5m)

Process

When this command runs:

1. Check connection:

   adb devices
   

2. Clear buffer (if --clear):

   adb logcat -c
   

3. Run logcat with filters:

   Default (FTC-relevant):

   adb logcat -v time RobotCore:* FtcRobotController:* TeamCode:* AndroidRuntime:E *:S
   

   Errors only:

   adb logcat -v time *:E
   

   Custom filter:

   adb logcat -v time <TAG>:* *:S
   

4. Format and colorize output:

   • Errors: Red
   • Warnings: Yellow
   • Info: Default
   • Debug: Gray

Output Format

Robot Logs (Ctrl+C to exit)
──────────────────────────────────────────────

12:34:56.789 [INFO]  RobotCore: OpMode 'TeleOp Test' initialized
12:34:56.823 [INFO]  TeamCode: Motor initialized
12:34:57.001 [WARN]  RobotCore: Battery voltage: 11.8V
12:34:57.234 [INFO]  TeamCode: Position: x=12.5, y=24.3
12:35:01.456 [ERROR] AndroidRuntime: FATAL EXCEPTION
                     java.lang.NullPointerException
                       at MyOpMode.loop(MyOpMode.java:45)

Common Filters

Your Code Only

/log --filter TeamCode

Hardware Issues

/log --filter RobotCore

Vision/Camera

/log --filter Limelight
/log --filter OpenCV

Crashes Only

/log --filter AndroidRuntime --errors

Error Handling

Not Connected

/log

  ✗ Robot not connected

  Run /connect first, then try again.

No Logs Available

/log

  No logs matching filter.

  Try:
  - Run your OpMode to generate logs
  - Use a different filter: /log --filter RobotCore
  - Clear and retry: /log --clear

Tips

Finding Crashes

When your OpMode crashes, look for:

/log --errors

The crash shows:

• Exception type (NullPointerException, etc.)
• File and line number
• Stack trace

Adding Your Own Logs

In your OpMode code:

// These show up in /log --filter TeamCode
telemetry.addData("Debug", "Motor power: " + power);
telemetry.update();

Or use Android logging:

import android.util.Log;

Log.d("TeamCode", "Debug message");
Log.w("TeamCode", "Warning message");
Log.e("TeamCode", "Error message");

Saving Logs

To save logs to a file:

adb logcat -d > robot_logs.txt