Choose a data source

The data source determines where xDrip4iOS obtains glucose readings.

Use Master mode when

  • this device should connect directly to a supported Dexcom, Libre, or Medtrum device
  • you want xDrip4iOS to receive readings without first downloading them from a cloud service.

Only one CGM device can be active. Display devices and heartbeat devices are separate groups in the Devices tab.

Use Follower mode when

  • the readings already exist in Nightscout
  • another app uploads readings to LibreLinkUp or Dexcom Share
  • another person shares readings through Calendar Share
  • the user has a Medtrum EasyView account
  • readings are available through a CareLink account
  • this device is used by a parent, partner, or caregiver.

Follower mode needs internet access. Select a Keep-alive option to help xDrip4iOS check for new readings in the background. iOS background limits can delay downloads when the app is not open. Review Permissions and background operation.

Configure Follower mode

Under Settings > Data Source, select Follower. Select the required service from Data Source, then select Status to open its settings.

Follower options in the Data Source section

The main screen also contains Pump & Treatments. Leave this set to Automatic unless you need to prevent online pump and treatment imports or select a different configured service.

Status opens the settings for the selected follower source. Use that screen to enter the account, site, or calendar details and to check the latest connection activity. A connected status confirms that xDrip4iOS can reach the source. Always check the glucose timestamp as well because a working source can still contain an old reading.

Background updates in Follower mode

Keep-alive controls how xDrip4iOS tries to check the follower source while the app is in the background.

  • Start with Normal.
  • Try Aggressive if Normal is not reliable enough.
  • Use Continuous only in extreme cases when both Normal and Aggressive do not work well enough. It plays silent audio continuously and has the highest battery use.
  • Use Heartbeat only with a separately configured Bluetooth heartbeat device.

iOS controls background operation, so no option can guarantee that every reading or alarm arrives at an exact time. See Follower mode for the full explanation.

Direct and cloud paths are different

A sensor can work through a Follower service even when xDrip4iOS cannot connect to it directly. For example, xDrip4iOS can download Libre 3 readings from LibreLinkUp, but it cannot connect directly to a Libre 3 sensor.

If you use CamAPS, the sensor determines whether xDrip4iOS can receive readings at the same time. Supported Dexcom sensors can work with both apps. Libre 2 and Libre 3 sensors cannot provide direct readings to xDrip4iOS while CamAPS is using them. See Using xDrip4iOS with CamAPS.