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Libre 2 - dumb questions

LittleGreyCat

Well-Known Member
Retired Moderator
Messages
4,384
Location
Suffolk, UK
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Dislikes
Diet drinks - the artificial sweeteners taste vile.
Having to forswear foods I have loved all my life.
Trying to find low carb meals when eating out.
In a few days I will start my first Libre 2.
I have read the documentation in LibreLink but it does leave a few unanswered questions, so here we go:

  1. Your phone and the sensor talk over Bluetooth so what happens if you turn Bluetooth off then on again an hour or so later?
  2. If you aren't using Bluetooth can you scan your sensor using NFC just like a LIbre 1?
  3. Can you use a Bluetooth speaker or set of headphones at the same time as the Libre 2?
Just wondering about things like battery saving and turning Bluetooth off for a few hours, turning it on for a reading, turning it off again. Not that I want to, necessarily, but wondering what happens.
My main gain from Libre 2 should be not losing readings over night or when I forget to scan during the day.
 
I have just started using mine today.
1. Bluetooth is used for alarms so you would lose alarms if you turn it off but that's all as far as I can tell.
2. Scanning still works by NFC if bluetooth is off.
3. I don't have any experience of this but I believe it should be ok as presumably Libre does not have the same bluetooth profile as audio devices.
I don't understand your last sentence.
 
I agree with 1 and 2 above.
I have turned low alarms off because it was going off all the time, especially at night when it was recording under 3.9. I then tried resetting the alarm but the lowest it can be set to is 3.3 and it was till going off in my sleep, I think when I turned over to my left side where the sensor is.
By turning Bluetooth off I lose high alarms too, not a problem for me but might be for some.
As long as you scan every 8 hours it remember those 8 hours. I often sleep longer than 8 hours so have been waking for quick scan than back to sleep again.
I haven't tested what happens if I don't scan within 8 hours, as I only have this free for 2 weeks I want as much data as I can get.

It has been eating into my battery and my phone seems slower on everything else. That might just be local signal problems, can't trace it specifically to libre2 but have suspicions

Haven't tried with speaker or headphones
 
Regarding point 3, you can attach multiple devices to your phone over Bluetooth.
I use it for my sensor, my pump, my speakers and sometimes connect it to my car.
 
Mr_Pot said:
I don't understand your last sentence.
Click to expand...

I am assuming that when Bluetooth is on, that readings are recorded via Bluetooth.
The sensor can also send alarms.
I therefore assume that if I leave my phone on with Bluetooth running overnight then all my readings will be recorded to the phone.
On Libre 1 if I forget to scan (or sleep longer than 8 hours) then data is lost.
I am assuming the main gain for me with Libre 2 is that I don't have to remember to NFC scan my arm at least once every 8 hours.
 
I will try to resist the temptation to scan if I wake up in the night tonight and see what happens.
 
As far as I understand it, everything is the same as Libre 1, except alarms are sent over Bluetooth. If you don't scan you won't see any data.

Later phones have Bluetooth that sits quietly unless something wakes it eg NHS tracker, so hopefully battery drain shouldn't be too bad.

Just had a wacky thought, if you turn app alarms off, then you won't need Bluetooth on, on the phone, but you could carry reader just for alarms. Not tried this just thinking aloud!
 
Mr_Pot said:
I will try to resist the temptation to scan if I wake up in the night tonight and see what happens.
Click to expand...

I assume that if the sensor is sending to LibreLink then if you look at the graph you should see it updating without an NFC scan.
I will be disappointed if alarms are the only new feature because I'm not sure that they would make any difference to me.

If I go high, not much I can do but wait.
Likewise if I go low, which I think only happens if I sleep on the sensor.
 
After the posts last night I turned Bluetooth off. Yes I have lost the alarms but only the alarms. The readings are still sent after an nfc scan, so yes you do still have to do it every 8 hours.
 
MrsA2 said:
After the posts last night I turned Bluetooth off. Yes I have lost the alarms but only the alarms. The readings are still sent after an nfc scan, so yes you do still have to do it every 8 hours.
Click to expand...

The scanning every 8 hours is a bugbear of mine. With my last sensor (Lire1) on day 14 I overslept and lost 8 hours of data.
I would hope that with bluetooth on overnight the readings would be updated regularly, so you could oversleep. During the day there is no difficulty scanning at least once every 8 hours.
 
Libre 2 is still a 'flash' device and not a GGM. You'll have to wait until Libre 3 for that according to the rumours.
 
Tested the Libre 2 last night with Bluetooth on. I didn't scan for about 9 hours and there is a 1 hour gap in the data. Sorry to disappoint you @LittleGreyCat. As @barrym says maybe with Libre 3. Why is your data important overnight anyway? If like me you don't have to worry about hypos then there is not much data of interest during the night.
 
Mr_Pot said:
Why is your data important overnight anyway? If like me you don't have to worry about hypos then there is not much data of interest during the night.
Click to expand...

Well, I have extended Dawn Phenomenon where my BG sometimes starts climbing after midnight and continues climbing to midday.
So it is useful to know if my BG has been flat overnight followed by a spike in the morning, or if it has been on a steady climb, or if it jumped in the early hours then plateaued.

This helps to add context to the previous day.
Sometimes a food will not spike me (much) during the day but there is a delayed reaction overnight.
All part of keeping my eating within a reasonable range without the massive burden of limiting myself to very few choices which I find both boring and an incentive to "just try something else this once".
 
You might find these two posts useful:
The Libre2 bluetooth communication with LibreView app on the phone is only for Alarms. However, if you install the third party app "Diabox" it will fetch the data over bluetooth automatically helping you avoid the scanning. The pdf in second post above have detailed instructions on how to get the app and set it up.

Hope it will be helpful for some.
 

That is truly disappointing.
 
mattrix said:
That is truly disappointing.
Click to expand...
As I said, the gap in the data is not a problem for me, my readings overnight are pretty much a straight line anyway. I am a "casual" user where individual readings are interesting but not important. If I depended on not losing data I would be investigating Diabox app that @nutribolt mentions above. I don't know anything about Libre 3, maybe that will be a true CGM or at least have more memory for data.
 
@LittleGreyCat

According to nutribolts blog, the data is available over the Libre2s blue tooth.
It is just the Abbott LibreLink app that does not have the ability to use this functionality.
As was pointed out diabox seems to be able to do it.
 
Last edited:
mattrix said:
According to nutribolts blog, the data is available over the Libre2s blue tooth.
It is just the Abbott LibreLink app that does not have the ability to use this functionality.
As you pointed out diabox seems to be able to do it.
Click to expand...
I think the point is that the Librelink app does not "ask" the sensor for its stored data automatically, it relies on you swiping the sensor. I am sure there must be a good reason or limitation that led to Libre using NFC rather than Bluetooth but I don't know what it is. As NFC only has a range of 10cms or so it is no use for initiating an automatic timed scan by the app..
 
Hi all wasn't sure where best to ask this but just had some diabox questions. I have it downloaded, due to start libre 2 sensor tomorrow eve. I've tried the bubblan website diabox guides but those pages come up blank for me?

Do I need a diabox account? It didn't ask me for any info... I've successfully signed into libre view on my diabox app.

Once I've activated my libre 2 sensor via libre link nfc (with location permission turned off so it doesn't connect to bluetooth) do I then choose 'add CGM' in the diabox app and let it search for the libre 2 via bluetooth?

Also, just to confirm, because I've set up diabox with my libre view account my diabetes team should still get the data like before (condition of me keeping libre on prescription)? Thanks in advance, cant wait to try the libre 2!
 
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