Comments on FreeStyle Libre Reader device versus the LibreLink app

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Marike

Hi, very useful information, thanks. I do have one question. You say “ You notably can’t use the Reader if you’ve activated the Sensor using the app.” But later say you use the read during sleep and app during the day.

Just to confirm, can you use the reader and phone app at the same time or is it one sensor per reader/app and I would have to wait 14 days for a new sensor if I wanted to change device.

Thanks for any help and I hope what I said make sense

> Just to confirm, can you use the reader and phone app at the same time

Yes, but you must activate the sensor using the Reader first and then the phone app. You’ll only get alerts on the first device you activate, though. So, you can read the data with the phone app and read and receive alerts on the Reader.

I’ve stopped using the Reader and only use the app nowadays. I prefer receiving alerts on my phone. It took a while to trust my phone to do it properly, though. You need to carefully adjust notification settings to bypass Do Not Disturb mode and disable all background limitations/battery optimization for the app. Otherwise the alerts might not work.

> […] would [I] have to wait 14 days for a new sensor if I wanted to change device.

A sensor can be activated on up to four devices, but with the same limitation as above. Only the first device will receive alerts, but you can use multiple apps to read the sensor.

Bruno

Just got a phone with NFC capability...so i run to the APP to see how it would work.

The thing is. The values between APP and Reader are different, like sometimes around 20 points. This makes no sense because the value is stored in the sensor not in reader or the phone...

Have you, or did you, experience anything similar? I will start comparing the values with the ones taken from blood to see who is the closest but in the meanwhile, do you know?

> The values between APP and Reader are different, like sometimes around 20 points. This makes no sense because the value is stored in the sensor not in reader or the phone...

The Sensor only stores raw sensor data and not glucose levels. It’s not in your bloodstream, just your interstitial fluids. The app or Reader interprets the data into a glucose reading. so, the calculations on your phone is probably using a newer algorithm than your Reader. The app gets updates every now and than and improve over time. The Reader doesn’t.

However, if you’re seeing large differences then you should control with a regular blood test. That’ll help you confirm that your Sensor is working properly.

Martin Biermann

There is one killer argument for me to use the Libre2 App on my phone: It will send discrete vibration alarms to my Wear OS smartwatch. Enough to wake me, but not my wife. Still, setting up reliable alarms 24/7 is quite challenging depending on your phone and your watch. Even though I prefer Sony, the combination of a Samsung S21 and the Galaxy Watch 4 works best.

Anonymous

Does the app will show sugar level for every 15 minutes even when I sleep?

> […] setting up reliable alarms 24/7 is quite challenging depending on your phone and your watch.

The new Libre 3 sensor has a few officially supported Android smartwatches. They all rely on notification synchronizationy but they should at least be tested by Abbott and found to be reliable.

> Does the app will show sugar level for every 15 minutes even when I sleep?

The app (and reader) won’t show readings unless you scan it. However, it will trigger an alarm when your glucose levels go below or above your target range (as long as it is within Bluetooth range). So, it will alert and hopefully wake you if it drops too low or high.

Michael Bell

Hi. Do you know a way to amplify the reader alarms? My Samsung A53 is too awkward to use with the sensor. I'm on disability for my hands and arms. The alarm sound isn't loud enough to wake me. Thanks in advance. Mike.

Michael, here are some options for boosting the alarm volume on the FreeStyle Libre Reader:

1) Quick and dirty analog solution: Try placing the reader device in a thin drinking glass or other container that won’t block the Bluetooth signal. It can work as an amplifier for the speaker, but I don’t know how well it might work or how much of a boost you need.

2) There’s a lot of options for hearing aids and small devices that can pick up on alarm sounds and amplify them. Check on Amazon and see if you find something that might be suitable.

3) It should be relatively simple to either swap out the internal speaker with something louder or hijack the signal. You may not be confident in your own skills in working with electronics. Reach out to your local makerspace/hackerspace and see if someone there is willing to help you modify the device. (It’s a small project and someone may enjoy the challenge.)

Mel

Thank you for writing abouto this. I'm using the sensor on my dog for a glucose curve. He has been diagnosed with diabetes a month ago, and we started him on 8 units of insulin a day. I chose not to buy the Reader, and have been using the app. His readings are consistently 500 (probably more, but that's the limit on the graph) no matter whether he's eaten, been shot, exercised, etc. I was wondering if maybe the app wasn't accurate, but from your valuable experience it sounds like that's probably not the case. We just need to keep working on what the appropriate insulin dose will be. Thank you!

Mel, I'm not a doctor and this isn't medical advice. You should verify the readings with a regular blood test to verify their accuracy. The sensor doesn't measure blood glucose directly, and the algorithm might not work well on dogs. E.g. body temperature affects the readings. It might work fine, but don't trust the sensor reading blindly without verifying.

ali

I tried using the app after I had scanned on the reader, it didn't work, am I supposed to share it on the app to the reader for this to happen? I literally have two in my arm, one for each, to see how this works and how different the readings are, wish I had seen this before I put in two, just 10 minutes ago, lol. Abbott has replaced my reader like 6 times in the past 2-3 yrs, and I hesitate to ask for another, so thought I would try the app first. BTW, the reason I was searching was to see how the battery fairs out with the app, but I didn't see anything on that.

Ali, as mentioned in the article: You must scan the sensor with the app first and then you can scan using the reader. It doesn’t work the other way. The first device you scan will receive the alarms.