Hi everyone,
today I present my second app: Libre CGM.
If you have a libre CGM aka Constant Glucose Monitor, you might be interested to have it available in homey. Here is your chance now.
Requirements:
- Libre CGM sensor (obviously)
- Libre Link UP account
- Sensor shared via Libre Link UP
Add as a device, login and choose the person to track. Thats it. You will have a device available with all infos the sensor offers via the api from libre LinkUp.
Use at own risk!
This app is not officially supported by Abbot. It was build with the work of others. If Abbot changes their API for the LibreLinkUp app this integration will most likely fail.
Also: I can not take any responsibility of cases of failure. This app is only with informational character and does not serve medical purposes! You are responsible for tracking your health.
Here the link for the app in testing: Libre CGM | Homey
I hereby proudly anounce: The app is Live!
Libre CGM sounds like a great integration—bringing glucose monitoring data directly into Homey makes tracking much easier. Simple setup via Libre Link UP and sensor sharing means users can quickly access all CGM info in one place.
Exactly and with the Insights feature of homey you can see how the glucose was over night without opening the libre app on the phone. Plus you have all the automation and warning features of homey which makes it a nice thing to have.
But there is a catch: This integration is relying on LinkUp and a working internet connection between homey and LibreLinkUp and the API of LibreLinkUp. So the posibility to warn of low glucose levels heavily relies on these factors. If Abbot decides to change their API the integration will likely stop to work. If the internet connection fails it is the same problem.
Hello Florain,
Thank you for the application, would it be possible in the future to integrate a dashboard widget for integration, a bit like in the native application on mobile, graphic, medium, high and low value?
Bonne journée.
Olivier (other developper 
Nice Idea! Let me see what I can do.
Great! Works it also with the libre freesrtyle 2?
Hi,
to be honest: I do not know at all.
If you are able to share the sensor via LibreLinkUp there should be a realistic chance.
The only problem is: I can not test it, since I only have acces to Libre3 sensors.
Hi Florian,
Thanks for your quick response.
I have the Freestyle Libre 2; this also communicates with the Android LibreLinkUp app.
Installing your app on my Homey Pro 2023 went well.
Glucose lower/higher than, for example, 8.5 works fine.
Question
Glucose delta becomes more than 3 mmol/L for 10 Minutes
[1] What is being done here?
[2] Who checks this: the LibreLinkUp app, the sensor, your app on the Homey?
Hi,
so basically this is an automatically generated trigger from homey. My app reads the values from LibreLinkUp API. The delta is calculated as currentValue (from API) - previousValue (stored in device).
The values are reported to Homey.
The triggers I have actively defined are these:
All others are generated by homey. So I would assume: Homey compares the last 10 values (given the sensor reports once per minute) and checks if the delta value was bigger than 3mmol/L for 10 minutes. I do not have exact knowledge of how this trigger exactly works but I assume it would be that way. I think the implementation would be a rising edge trigger, but I am not sure. As the delta is always calculated as current - previous the Trigger might only work when one delta spikes above that value. Since a jump this high within 2 minutes (sensor once per minute) is a bit drastically I guess it would never trigger or only when something goes horribly wrong.
I think as a conclusion: It might be better to check more elaborated like: When glucose level falls below 90 mg/DL for more than 3 minutes and delta is more than x => Alarm
Thank you for your detailed answer. I can get back to work with this for a while!
Please keep in mind: The Libre sensor does not measure the real blood sugar. There is a delay of up to 10 minutes until you see the change in glucose! Any warning that you are creating on the libre values is some minutes old in reality. This is a situation that can not be overcome with any software. So please be aware of setting the warning levels early enough. And: a delta of 3 mmol is a drastic change this would be like injecting a high dose of insulin or injecting a glucose solution in the blood stream.
Hi Florian,
Thanks for your additional explanation and warning. I have been using the Freestyle since about the beginning.
A delta of 3 mmol/L is indeed drastic; it was an example with a random number.
Good luck with the further development of the app!
Does “delta is always calculated as current - previous” imply that delta can also be negative?
I can’t enter that, though 
Enough to keep me busy for a while 
Yes, delta is also negative:
In my homey flow i can also enter negative values:
Hi Florian,
It works on my PC too, I see now.
I don’t remember where it failed.
Probably a mistake on my part somewhere.
Thanks for your reply!
One more question, though.
In Homey > Tile > Chart > Glucose > in mg/dL.
How do I convert this to mmol/L?
Regards, Kees Koopman
You mean the dashboard widget?
