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A FreeStyle Libre Update

The last time I wrote anything interesting about Abbott’s flash glucose monitor (don’t call it a CGM) was when I compared it with the underwhelming Dexcom G6. I thought it would be a good time to provide an update, what with Abbott sending a number of email reminding you to update their FreeStyle LibreLink app in the past couple of weeks.

First of all, there’s the matter of supplies. Back in January, I decided to test Dexcom’s CGM because Abbott’s supply issues bit me in the backside, as I could not get new sensors to keep up with my usage — particularly as the more active life in London with my girlfriend meant losing a couple more sensors to mistakes, such as bumping into the doorframe. For a while, you could only buy three sensors every 25 days, and even then, sometimes the lead time to fulfill the order would be over a week; nowadays this appears to be much better, and the time limit for the orders was removed recently.

Since I was not particularly thrilled to switch to the Dexcom G6, I had to find a way around these limits, beside counting on the two extra sensors I “gained” by not using the Libre for a month. Luck was that a friend of my girlfriend found the Libre sensors on sale in a brick-and-mortar store in Sharjah, and managed to send me six of them. The store had no limits on how many sensors you could buy, despite the FreeStyle UK website only allowing orders of three at most, and only to already-established customers.

The UAE-bought sensors are effectively the same as the British ones, with the same manufacturing information printed on them, and even similar enough lot numbers. The most visible difference is that the two alcohol-soaked tissues, provided for cleaning the insertion point, are missing.

The other difference is not visible in the packaging, or indeed on the hardware itself: the sensors are region-locked. Or maybe we should say that the app is. As it is, my (UK) FreeStyle LibreLink install did not want to set up the UAE-bought sensors. The reader device had no such concern and both initialised and read them just fine. I was originally a bit concerned and spot-checked the values with fingersticks, but it looked like there was no issue with the sensors at all.

I’ve been wondering just how much the supply problem connects with the region locking. Or just how fine-grained the region locking is: my Irish sensors worked perfectly fine with the UK app, although by that point, the app was not available in Ireland at all. But possibly all of these problems are gone.

Now, to go back to Abbott’s email messages to update their LibreLink app. The reason for this update is not much about the UI of the app itself – although that did change a bit, in subtle and annoying ways – but rather a change in their algorithm for turning the sensors’ readings into a human-understandable blood glucose reading. The “curve”, as it’s sometimes referred to. It’s important to note that what the sensors communicate with either the app or the reader device are not “fully cooked” blood sugar readings, but rather a set of different sensors reading, and that the app and reader will then apply some formulas to provide an equivalent reading to a fingerstick.

Much more interesting to me, in the announcement of the new curve, is that they also suggest users to update the firmware of reader devices to make use of the new fine-tuned algorithm. This is interesting because it makes the FreeStyle Libre the first glucometer with an upgradeable firmware. I have not actually run the update myself, yet. It needs to be done just before changing the sensor, as the reader will forget about its last sensor at that point, and I’m a bit worried that it might not work with UAE-bought sensors anymore after that. So I’m instead waiting to finish the supply of those sensors, and maybe get another one later to test after the update.

I also want to try to get a usbmon trace of the whole procedure for the firmware update. I’m not sure when Abbott will ever publish another update for the reader, but at least starting collecting the protocol would be interesting. Once I do that, you can expect another blog post on the topic.

And as a final note, glucometerutils is being updated as I type this to support reading and setting patient names. While I would not suggest people to use that field for their own personal glucometer, I thought it would be nice to provide the building block for more doctor-focused apps to be built out of it. As a reminder, the code is released under the MIT license, because using it to build something else is a primary focus of it — we need better tooling for glucometers, and not just in the Free Software world, but in the world in general!

Comments 8
  1. Abbott emailed me about the firmware update too. I tried to no avail to update my FreeStyle Libre 2 sensor with the new firmware. The firmware update website doesn’t clarify in any way whether the update is for the Libre 1 or 2 systems, and their support team had no idea either but just repeated that it was very important to update the firmware. Do you happen to know whether the firmware is for both systems or not?


    I’m using the Norway-region locked app which is missing features and integrations that are available in other countries. Whatever happen to the EUC’s plan to have a single digital marketplace for Europe and all of that?

    1. Hi Daniel, do You already know whether it is possible to update freestyle libre 2 reader using the abbott’s website? I’ve got the same doubts and see no simple answer.

      1. I contacted Abbott and was told there is no update for the Libre 2 reader. However, the readings on the phone and reader now differ after an update to the app. I expect there will be a firmware update for the reader someday too.

  2. In Italy we haven’t yet the Libre 2 too. There was a notice by a person who updated his android app that Libre 1 sensors cannot be scanned if bluetooth is switched off, it gives an error message to turn on bluetooth.
    I guess this has to do with the updated app beeing ready for Libre 2.
    I think they want not to confuse people with too many libre apps in the store, for Libre 1 and 2, prefering to have one app for all.

  3. In Italy we haven’t yet the Libre 2 too. There was a notice by a person who updated his android app that Libre 1 sensors cannot be scanned if bluetooth is switched off, it gives an error message to turn on bluetooth.
    I guess this has to do with the updated app beeing ready for Libre 2.
    I think they want not to confuse people with too many libre apps in the store, for Libre 1 and 2, prefering to have one app for all.

  4. From your Facebook Photography page I see you love animals just like we do. Have taken many photographs of our squirrels and chipmunks. We even had a flock of seven wild turkeys stay over winter with us two years ago.…/AF1QipPwhObdmv58Z5xt0JUHRmi… For their night nesting, they flew way up into our huge Siberian Elm, taking off from about 150 yards down our street and flying up 60 to 75 feet in that huge tree. I enjoyed your bee pictures too. Our bees love our Mexican Sunflowers and Virgin Bower Vines ( Our Cat, Henri Matisse (, looks much like your beloved cat. I just wanted to share. I want express my understanding and sadness at what a huge loss their passing is. It is even greater than the loss of human friends sometimes. I’ve had to start looking at the loss a little differently recently. The first step to work through the sense of emptiness and loss of their presence and all the little antics and pleasures they gave us. Then after several months the loss becomes a little less emotional. I know as we have lost ours over the years, we have learned to look back with love, great joy, and pleasure and sadness too for all they gave to us and shared of their very surprising and creative ways of adapting to the worlds we provide to create relationships within.

    I too use the 14 Day FreeStyle Libre System you blog about. In America, we had the 10 day sensors at first and then in about April, 2019 we switched over to the 14 day sensors. Using the system and the data and reports it provides has enabled me to move my A1C from about 8.2 to 6 recently. Started to use it in December 2017 and within 2 months I had moved from 8.2 to about 6.6 A1C. I’m also using 75% less long acting insulin and with some low glycemic index suppers consisting of lentil stew, carrots, cole slaw, and one serving of crackers, about 102 carbs total, I have to take no short acting insulin at all.

    My endocrinologist said last week that he seldom sees numbers as low as mine have been from other diabetics. I told him that a great deal of that was attributable to his excellent, supportive, and very understanding and knowledgeable nurse educators and nurse practitioners who have helped me to work through the issues involved in controlling my blood glucose tightly.

    I only wish it was easier or possible to download my reader data easily to my iMac or my iPad Pro. The reader only keeps individual data points for about 40 days. I print out detailed 30 day reports and save them in Adobe Acrobat format so I can refer to them to them later and give my endocrinologist a color copy of those reports, but I’d like to be able to save the data itself for long-term study. Thank you so much for all the writing you are doing on this. I hope you can give some of us some leads on how to keep our data and download it to our computers without a great deal of difficulty.

    1. Hi Frank! Thank you very much for the lovely comment, and the videos — mrow! 🙂

      I’m really happy to hear that the Libre is working well for you, as it definitely has improved my life as well. I know a few people for which the Libre is not working out very well as well, so it’s important that tools match the problem people have.

      As for downloading data — should work on macOS but I’m not sure what’s the right path to use for hidapi to open the right device, and I have never tested it on it. If you feel like playing around with it, that might be an easy way to download the data, as you can export as CSV all the readings the device is willing to print out (which may or may not match what the original software can do, be warned.)

      There’s also at least one iOS app that supports this, because its author is the person who contributed the protocol information to implement it in my tools: I’m not sure if it’s available in the US though. I have not used it myself (haven’t used iOS or macOS in a long while), but Pascal’s been helping out with protocol documentation.

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