The Freestyle Libre 2 sensor is now a real CGM even with the official app. Still, LibreLink cannot send data to AAPS. There are several solutions to use it with AAPS.
Bluetooth transmitters can be used with the Libre 2 (EU) or 2+ (EU) and an out of process algorithm app. You can receive blood sugar readings every 5 minutes like with the Libre 1.
Check the bridge and app you want to use are compatible with your sensor and xDrip+.
The Libre2 OOP (find it here) is creating the same BG readings as with the original reader. AAPS with Libre 2 do a 10 to 25 minutes smoothing to avoid certain jumps. See below Value smoothing & raw values. OOP generates readings every 5 minutes with the average of the last 5 minutes. Therefore the BG readings are not that smooth but match the original reader device and faster follow the "real" BG readings. If you try to loop with OOP please enable all smoothing settings in xDrip+.
There are some good reasons to use a Bluetooth transmitter:
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You can choose various OOP2 calibration strategies (1): have the reader values using "no calibration", or calibrate the sensor like a Libre 1 using "calibrate based on raw" or ultimately calibrate the the readers like values with "calibrate based on glucose".
Make sure to leave OOP1 disabled (2).→ Hamburger Menu → Settings → Less common settings → Other misc. options
- The Libre 2 sensor can be used 14.5 days as the Libre 1
- 8 hours backfilling is fully supported
Remark: The transmitter can be used in parallel to the LibreLink app without interfering with it.
- → Hamburger Menu (1) → Start sensor (2) → Start sensor (3) → Answer "Not Today" (4).
This will not physically start any Libre2 sensor or interact with them in any case. This is simply to indicate xDrip+ that a new sensor is delivering blood sugar levels. If available, enter two bloody measured values for the initial calibration. Now the blood glucose values should be displayed in xDrip+ every 5 minutes. Skipped values, e.g. because you were too far away from your phone, will not be backfilled.
After a sensor change xDrip+ will automatically detect the new sensor and will delete all calibration data. You may check you blood glucose after activation and make a new initial calibration.
- In AAPS go to Config Builder > BG Source and check 'xDrip+'
- If AAPS does not receive BG values when phone is in airplane mode, use 'Identify receiver' as describe on xDrip+ settings page.
:class: warning
xDrip+ doesn't support direct connection to Libre 2 US and AUS.
Only Libre 2 and 2+ **EU** models.
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Follow these instructions to setup xDrip+ as the original documentation links to an obsolete OOP2 version.
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Follow setup instructions on xDrip+ settings page.
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Select xDrip+ in in ConfigBuilder, BG Source.
(libre2-value-smoothing-raw-values)=
Technically, the current blood sugar value is transmitted to xDrip+ every minute. A weighted average filter calculates a smoothed value over the last 25 minutes by default. You can change the period in the NFC Scan features menu.
→ Hamburger menu → Settings → NFC Scan features → Smooth libre 3 data when using xxx method
This is mandatory for looping. The curves look smooth and the loop results are great. The raw values on which the alarms are based jitter a little more, but correspond to the values that the reader also displays. In addition, the raw values can be displayed in the xDrip+ graph in order to be able to react in time to rapid changes. Please switch on Less Common Settings > Advanced Settings for Libre2 > "show Raw values" and "show Sensors Infos". Then the raw values are additionally displayed as small white dots and additional sensor info is available in the system menu.
The raw values are very helpful when the blood sugar is moving fast. Even if the dots are jumpier you would detect the tendency much better as using the smoothed line to make proper therapy decisions.
→ Hamburger menu → Settings → Less common settings → Advanced settings for Libre 2
You can calibrate the Libre2 with an offset of -40 mg/dl to +20 mg/dL [-2,2 mmol/l to +1,1 mmol/l] (intercept). The slope isn't changeable. Please check by fingerpricking after setting a new sensor, keeping in mind it might not be accurate in the first 12 hours after insertion. Since there can be large differences to the blood measurements, verify every 24 hours and calibrate if necessary. If the sensor is completely off after a few days, it should then be replaced.
- Install Diabox. In Settings, Integration, enable Share data with other apps.
- Select xDrip+ in in ConfigBuilder, BG Source.
See here.