The Solo Controller communicates with you primarily via its screen. If it displays different message alerts based on the current status of Solo and the Controller. For brief explanations of the various message alerts, consult this article.
Solo is calibrating your current altitude. Please wait.
Solo is calibrating. Please wait until finished for optimal performance.
Solo is performing a compass calibration. Please wait.
Solo requires a level surface to take off from. Place Solo on a level surface to clear this alert.
Solo requires a level calibration. Perform a level calibration in the 3DR Solo app to clear this alert.
Solo requires a compass calibration. Perform this calibration in the 3DR Solo app to clear this alert.
Solo encountered a calibration error. Restart Solo to clear this alert.
Solo encountered a sensor error. Restart Solo to clear this alert.
You have reached the maximum altitude. Fly lower to clear this alert.

Solo has been disconnected from the app. Make sure your mobile device is on and that your Wi-Fi is connected to the app. Click here for information on connecting to Solo Wi-Fi.
The 3DR Solo app successfully connected to Solo.

The controller has been disconnected from Solo and will Return to Home. Objects like buildings and trees can block the communication signals between Solo and the controller. Make sure your line of sight with Solo is unobstructed and that the controller has power.
Solo has lost the controller signal and as a result will Return to Home. Make sure your controller is powered on with enough battery to operate.
Solo has recovered the controller’s signal. Press the Fly button to regain manual control.
Solo lost GPS connectivity. Make sure nothing is obstructing the signal between your controller and Solo.
Solo has established a GPS connection and will now switch back to Fly.
If you have lost GPS, you will then be placed in Manual flight. Solo does not automatically balance itself in Manual, so you will need to carefully guide Solo to its landing spot.
Solo needs to be serviced. Use the app to submit a trouble ticket with 3DR Support to clear the alert.
Solo encountered a control stick error. If this controller stick error is received in flight, Solo will return home and land. Use the app to submit a ticket with 3DR Support.

Solo has reached 25% battery. Return to Home soon to prevent a crash.

Solo has reached a critical battery charge of only 10%. Return to Home immediately to prevent a crash.

With a 10% charge you have very little time to land. Return to Home immediately to prevent a crash.

Solo has run out of battery and is returning home. If your battery was drained to 0% it is possible irreversible damage has occurred. Recycle this battery just to be safe.

Your controller has reach a low battery charge of 10%. Charge the controller soon to avoid unexpected flight behavior.

Your controller has reached 5% battery. End your flight immediately and charge the controller. If you continue to fly you are in serious danger of crashing.

Your controller is completely out of battery! Solo is returning home for you to try to prevent a crash.