Sleep Mode
Sleep mode is a feature that allows MagicLeap 2 to conserve battery life by turning off the display and suspending the applications when the device is not in use. Starting from OS version 1.3.0-dev2, sleep mode is enabled by default for all devices. This means that your applications need to handle the events of entering and exiting sleep mode properly, otherwise they may encounter unexpected errors or crashes.
For applications built with Unity, the easiest way to ensure compatibility with sleep mode is to upgrade to a newer Magic Leap Unity SDK (1.9.0) or later, which handles the sleep events automatically. For native applications, you should follow some of the best practices listed in the Best Practices section of this article, such as saving the application state, releasing resources, and resuming gracefully.
This change is scheduled to take effect in September 2023 onward. However, if your device is new, or you do a factory reset update on an existing device, sleep mode will be enabled by default starting in early August 2023.
Updates to Your Device
After sleep mode is enabled by default, if you choose to update your device with a regular update, your existing settings will be saved, and sleep mode will still be optional (the default will be Standby enabled). If your device is new, or you do a factory reset update on an existing device, sleep mode is enabled by default. Keeping sleep mode set by default can greatly extend the length of time your device can go without recharging.
About the Standby Mode Feature
You can opt to enter standby mode if no face is detected by choosing the Compute Pack Standby setting in the UI. For more information about configuring standby mode, see the Standby Mode article in the Magic Leap Care Center.
About the Sleep Mode Feature
You can enable or disable the sleep mode feature using the battery settings by toggling the Sleep Mode option.
When you choose to enable Sleep Mode, you’re also able to choose when Sleep Mode is activated.
Best Practices
This section covers what you’ll need to keep in mind when handling Standby and Sleep modes.
- From the Android activity lifecycle perspective, both Standby and Sleep mode can be treated in the same manner as Android Doze.
- When entering Android Doze, the screen is turned off. Following the standard Android activity lifecycle logic, screen off will trigger the onStop event broadcast to applications.
- Follow the guidelines for the Android activity lifecycle with your application.
- When resuming back to the Normal operating mode, the onStart event will be broadcast.
- Your app should listen for onStop/onStart and handle issues that can arise from going into and coming out of Standby and Sleep modes.
- When your application returns from Standby or Sleep, some API features may return error states as the device resumes. Some services may not be automatically reconnected. For example, both Standby and Sleep will cause a loss of head pose and network access. Sleep mode will cause a loss of WiFi and Bluetooth connectivity and all core services will be suspended. These services will always be resumed upon the device wake. But your application needs to take into consideration all the APIs you have running and check to make sure they are appropriately reconnected or restarted as needed.
- You can learn more about how to handle Standby and Sleep in your application by first reviewing the Android documentation on Standby Doze. Second, review the additional information unique to the Magic Leap 2 platform in the diagram and charts below.
- Remember that from the application perspective, onStop will be broadcasted to indicate both Standby and Sleep. This means that onStop application logic must be generic in handling both Standby and Sleep.
Standby and Sleep for MagicLeap 2
| Power State | Description |
|---|---|
| Standby | Display placed into standby (screen off) |
| Standby | Audio powered off |
| Standby | Application processor still up and running |
| Standby | Networking and application access to networking is limited |
| Standby | Totem controller placed in standby |
| Standby | All peripheral sensors and cameras placed into Low Power state |
| Standby | Head Pose Tracking is suspended |
| Standby | Upper Face Detection continues to run |
| Sleep | Display powered off (screen off) |
| Sleep | Audio powered off |
| Sleep | Application processor suspended and placd into low power state |
| Sleep | All system services and applications suspended |
| Sleep | Network unavailable |
| Sleep | Totem controller placed in standby |
| Sleep | All bluetooth devices are disconnected |
| Sleep | Loss of adb shell access |
| Sleep | All peripheral sensors and cameras placed into Low Power state |
| Sleep | Head Pose Tracking and Upper Face Detection suspended |