BBL Compare

BBL Compare opens two Betaflight Blackbox .bbl files in independent side-by-side panels. Each panel runs its own analysis, so you can review gyro traces, PID responses, spectrum data, and configuration metadata for both files without switching between tabs or losing context.

The most common use case is a before/after tune comparison: load the log from the previous session on the left and the new session on the right, then step through the same time region in both panels to see what changed.

How to start a comparison

There are two ways to enter Compare Mode:

From the Log Analyzer list

1. Open Log Analyzer.
2. Enable Compare Mode using the toggle in the file list header.
3. Select the first file — it is assigned to panel A.
4. Select the second file — it is assigned to panel B.
5. Click Compare to open the side-by-side view.

From UAV Management

1. Navigate to a drone in UAV Management.
2. Open the Flight BBL Logs section.
3. Select two BBL entries and click the Compare button.

What each panel shows

Both panels are fully independent instances of the analyzer. Each one provides:

• Analyzer tab — spectrum analysis including FFT, PSD, frequency-vs-throttle heatmap, and PID error view for the file assigned to that panel.
• Setup / Config tab — firmware metadata such as looptime, craft type, PID values, and filter settings as recorded in the log header.

The panel header shows the drone name and the source file name so you always know which log is on which side.

Tips for effective comparison

Getting reliable results from a side-by-side comparison requires some discipline in how you set up both panels.

• Start with the Setup / Config tab on both sides before looking at graphs. Confirm that looptime and craft type match — differences here can produce misleading visual results in the Analyzer.
• Use the same spectrum type (FFT or PSD) in both panels. Mixing types changes the amplitude scale and makes peaks appear larger or smaller than they are.
• Apply the same throttle range filter in both frequency-vs-throttle views. Comparing different throttle windows will produce different heatmap patterns even if the tune is identical.
• Focus on a specific axis first — roll, pitch, or yaw — rather than switching axes between panels. This keeps the comparison focused.
• A meaningful comparison needs logs captured under similar flight conditions. Different maneuvers, airframes, or battery states will produce differences unrelated to the tune itself.

Returning to a single-file view

Use the Back button to return to the Log Analyzer without clearing the selected files. Use Exit Compare to clear both selections and return to the standard single-file view.