Using the Freestyle Libre with third party transmitters


Thanks! this is a lot of good info here. One question: You talk about NFC enabled smartphones with bluecon and miaomiao. I have the understanding that the intermediate sensor (bluecon/miaomiao) reads the NFC signal and transmits it via Bluetooth to the phone or other device. Is this correct?

That is correct. If you are using a transmitter accessory, it acts as the NFC data collector, then transmits it to a smartphone (or even a smartwatch?)

But, using 3rd party apps such as Glimp or Diabetes:M, you can use a compatible NFC enabled Android smartphone to act the same as the factory reader. Except that the app allows for the sensor data to be calibrated unlike the standard reader.
You do have to activate the sensors with the original reader if you want it to be able to read the sensor. But it is also entirely possible to activate the sensor using a 3rd party app, if you only intend to scan it with your smartphone device. Using these apps on an NFC enabled smartphone also extends the 10 day sensor to the full 14 day operation, and cuts the warm up time down to 1 hour. In fact, I typically get my first readings within about 30-45 minutes after activation.
The Glimp website has a somewhat outdated compatibility list. For myself, I took one of the Verizon variants of the Samsung Galaxy S4 smartphones that I had previously retired, and put it back into service. It actually works quite well for this type of purpose, and refurbished units are readily available at bargain prices.
The gotcha is that you must use an authentic Samsung battery, since the NFC antenna for these smartphones is incorporated into the battery. Off brand batteries will frequently delete this component, and you will wind up having circular conversations with yourself trying to figure out why your NFC enabled smartphone won’t actually do any NFC actions. (don’t ask me how I know this!)

I’m currently running Glimp and Diabetes:M in parallel but you could run one, or the other, or even configure things in such a way that Glimp feeds it’s data directly into Diabetes:M. Both apps are free, but the Diabetes:M app does have a premium version, a yearly subscription currently runs $50, which unlocks additional features, such as sharing data on multiple devices, etc.

Glimp Screenshot

(note that the red dots are manual blood glucose entries)

Diabetes:M Screenshot

(note that the orange crosses dots are manual blood glucose entries)

Also note that these two screenshots were of asynchronous times. My last concurrent scan showed them with only 1 point variance. The factory scanner read about 10 points higher during the same scan window. This sensor has been in use for a few hours past 7 days, with a 12 hour pre-activation insertion.
And for reference, the factory scanner tells me the sensor will expire in 4 days. Diabetes:M tells me that the sensor will expire in 6 days and 23 hours. Glimp tells me that the sensor has been in use for seven days. It will let me collect readings for up to 14-1/2 days before it will insist on a new sensor.