How to Calibrate a Tello Drone: IMU Calibration Step by Step
Calibrating a Tello means running the IMU calibration in the Tello app, which resets the drone’s motion sensors so it hovers level and doesn’t drift. Charge the battery above 50%, remove the propellers and guards, connect to the app, open Settings > More > Calibration (IMU), and follow the on-screen sequence: place the drone flat, then on its right side, left side, nose down, nose up and upside down, waiting at each step until the app moves on. When it finishes, restart the drone.
By Kyle HilsonUpdated: October 20263 min read
When to calibrate
- The Tello drifts in one direction while hovering in calm air.
- The app shows an IMU warning or asks for calibration.
- After a crash or a firmware update.
- If the drone won’t take off and shows a sensor error.
Don’t calibrate unnecessarily: if it flies fine, leave it.
Before you start
- Charge the battery to above 50%; see how to charge a Tello.
- Remove props and prop guards.
- Find a flat, level, stable surface away from metal and magnets.
- Connect your phone to the Tello’s Wi-Fi and open the app.
The six positions
| Step | Place the Tello |
|---|---|
| 1 | Flat on its belly |
| 2 | On its right side |
| 3 | On its left side |
| 4 | Nose pointing down |
| 5 | Nose pointing up |
| 6 | Upside down |
At each step, wait until the app’s drone model moves to the next position before changing. Hold the drone still; movement during a step can spoil the calibration. When the app says calibration is complete, restart the drone.
After calibration
Refit the props and guards, take off in a calm indoor space and hover at about 1 m. If it still drifts slightly, the downward vision sensor may struggle with the floor: Tello holds position best over patterned, well-lit surfaces, not plain shiny or dark floors. Try a rug or textured mat.
Other causes of drift
- Poor lighting or plain floors confuse the downward camera.
- Draughts from fans or air conditioning.
- Bent or damaged props.
- A dirty camera or sensor window underneath.
- Low battery.
If calibration fails
- Restart the drone and app, then try again.
- Update the app and drone firmware.
- Check the battery is well charged.
- Make sure the surface is truly level.
- If it fails repeatedly, the IMU may be damaged; contact support.
If the app can’t connect at all, see why a Tello won’t connect.
Tips
Calibrate at room temperature; a cold drone straight from a car can give poor results. Keep a small box or book nearby to help hold the drone steady in the nose-up and nose-down positions.
The vision positioning system
Besides the IMU, the Tello uses a downward camera and sensor to hold its position indoors. It works best at heights below about 10 m over textured, well-lit surfaces. Over water, glass, plain carpets or in dim light, it can’t see enough detail and the drone drifts, even with a perfect IMU calibration. Keep the sensor window clean and fly over patterned floors for the steadiest hover. Outdoors in wind, the Tello can’t hold position well at all, since it’s a light indoor-focused drone.
If the drone still won’t hover steadily after calibration and good lighting, try a different battery and update the firmware before assuming hardware damage.
FAQ
How do I calibrate a Tello?
In the app: Settings > More > Calibration, then follow six positions.
Why does my Tello drift?
IMU needs calibration, or the floor is too plain for the vision sensor.
Do I remove the props?
Yes, remove props and guards before calibrating.
How often should I calibrate?
Only when it drifts or after crashes and updates.
More on this topic: the complete RC Drones guide covers the basics behind this article.
About 20 years in RC. Mostly boats in the NAVIGA Mini Eco Expert class, with many self-made parts; also a King Motor Baja 5B, a home-built electric plane, home-built nitro planes he has flown, and an RC helicopter. More about SwellRC
