Reading Blackbox Logs

Reading Blackbox Logs

Blackbox is the truth. Feel can lie; the log doesn't.

Loading a log

Use Betaflight Blackbox Explorer (web or desktop). Drop the .bbl file in.

Key traces

• **Gyro vs Setpoint**: tracking — should overlap most of the time. Gap = lag.
• **Motor outputs**: should not pin to 100%. If they do, that's saturation.
• **D-term**: high spikes mean bad noise; consider lower D or better filtering.

FFT view

Switch to FFT to see frequency-domain noise. Peaks at motor RPM = unbalanced props or worn bearings. Wide low-frequency rumble = frame flex.

Workflow

1. Fly a known move (punch out, freestyle line, hover). 2. Pull the log immediately while you remember. 3. Annotate timestamps in the log explorer. 4. Compare across tunes — keep a folder per tune session.