Blackbox

The Blackbox tab configures flight-data logging -- which fields are recorded, logging rate, and (if fitted) onboard flash/SD storage management. Blackbox logs are the primary tool for diagnosing tuning issues after a flight, and are usually the first thing to attach when asking for tuning help.

When it logs

Device picks where logs go: onboard flash, an SD card, or an external serial logger (each only appears if actually fitted/supported). Mode then decides when logging is active: Armed (simplest -- logs every flight), Normal (logs only when armed and a Blackbox switch is active, for keeping only flights you deliberately flag), or Switch (logs whenever that switch is active, armed or not). Grace Period keeps logging briefly after disarming, specifically to catch the moments right after a crash rather than cutting off exactly at disarm.

Rate and fields

Rate of Logging is a divisor of the PID loop rate -- higher rates capture more detail (useful for chasing a specific fast oscillation) at the cost of filling storage faster; lower rates log longer flights in the same space. The field checkboxes choose which data categories are recorded at all -- turn off what you don't need to save space, but when in doubt for a tuning question, leave gyro/PID/setpoint data on since that's what most tuning advice is read from.

Debug Mode adds a further 8 extra values on top of the normal fields, for a specific diagnostic (its exact meaning depends on which mode is selected) -- leave it on NONE unless you're chasing something specific that calls for it.

Flash storage

Initial Erase guarantees a minimum amount of free space before recording starts, erasing old logs if needed -- note that erasing can take a while on some flash chips, so recording doesn't begin until it finishes. Rolling Erase instead overwrites the oldest logs once storage is full, trading guaranteed history for never running out of space -- logs can gain gaps if the chip is slow to erase mid-flight.