FlySparkChirp autotune for Betaflight PID tuning
Tuning PIDs by feel takes many packs. A chirp test makes the flight controller sweep a sine wave through each axis while it logs, and the log then shows how the quad responds at every frequency. FlySpark reads that CHIRP log and suggests simplified slider values for Betaflight.
It runs in your browser or in the FlySpark app. With a flight controller connected, the suggestion can be applied directly.
Free. Hardware connections need Chrome or Edge on a computer; phones use the FlySpark app.
Features
Frequency response
The closed-loop response from setpoint to gyro on each axis, with coherence so poor data is ignored.
Stability margins
Phase margin, crossover frequency and loop delay, plus the peak sensitivity that flags a fragile tune.
Step response
An estimated step response for the first 100 ms, to see overshoot and rise time.
Slider suggestions
Recommended simplified tuning sliders, with the reason whenever the target cannot be met in full.
Apply when connected
With a Betaflight board connected, write the suggested sliders straight to it.
How chirp tuning works
During a chirp test the firmware injects a sine wave that slowly rises in frequency on one axis at a time. Logging with debug mode CHIRP records the sweep and the quad's response. From that, the transfer function shows how much the gyro lags and overshoots the request at each frequency.
Good tunes leave enough phase margin to stay stable while crossing over at a frequency high enough to feel locked in. FlySpark shapes the loop against a phase-margin target and keeps peak sensitivity at or below 2, then turns the result into simplified sliders. The numbers are a starting point: always test fly, check motor temperatures and confirm in the blackbox explorer.
Before you fly the test
Your Betaflight build needs the chirp feature, with the CHIRP flight mode on a switch and debug mode set to CHIRP. Log at a high rate, fly in calm air, hover at a steady height and trigger the sweep. A healthy, well-filtered quad gives much cleaner results; fix noise and mechanical problems first. Check the drone weather forecast for a still day.
Other tuning approaches
Many pilots tune with the Betaflight simplified sliders and blackbox step response tools such as PIDtoolbox or Plasmatree PID-Analyzer, which estimate step response from normal flying. A chirp sweep gives a cleaner measurement of the loop itself, which is why it suits a guided suggestion. Both methods end in the same place: sliders you confirm by flying.
How to tune Betaflight PIDs with a chirp log
- Set up the chirp. On a Betaflight build with chirp support, put the CHIRP mode on a switch and set debug mode to CHIRP.
- Fly the test. Hover in calm air and run the sweep on each axis while logging.
- Open the log. Open Chirp autotune in FlySpark and pick the blackbox log.
- Apply and test. Review the margins and suggested sliders, apply them, then test fly gently.
Frequently asked questions
Does Betaflight have autotune?
Recent Betaflight builds can run a chirp sweep and log it. FlySpark analyses that log and suggests slider values; you stay in control of applying them.
Is a chirp test safe?
The quad shakes noticeably during the sweep. Fly in an open area, at a safe height, and only on a quad that already flies well.
Do I need a flight controller connected?
No. You can analyse the log on its own. Connecting a Betaflight board lets you apply the suggestion.
Can it tune INAV or ArduPilot?
No. This tool is built for Betaflight chirp logs. ArduPilot has its own in-flight AutoTune.
Can I try it without a log?
Yes. Open Chirp autotune and choose the sample chirp flight to see the full analysis on simulated data.
Related tools
Blackbox explorer for Betaflight and INAV logs
Open Betaflight and INAV blackbox logs (.BBL, .BFL, .TXT) in your browser: gyro and PID graphs, noise spectrum, GPS track, video sync, CSV and GPX export.
Betaflight Configurator in your browser and on your phone
Set up Betaflight in your browser or on Android: ports, PIDs, rates, OSD, modes, presets and CLI over USB or Bluetooth. Free, with a no-hardware demo.
Drone flying weather: forecast and go / no-go
Can you fly your drone today? Hourly wind, gusts, rain, temperature, Kp index, GPS satellites, sunrise and dusk, nearby no-fly zones and a go/no-go call.
ESC configurator for BLHeli_S, Bluejay and AM32
Read and change BLHeli_S, Bluejay and AM32 ESC settings through your flight controller in Chrome or on Android. Flash ESC firmware and edit startup tunes.
Ready to try it?
Free. Hardware connections need Chrome or Edge on a computer; phones use the FlySpark app.