Broadcast to AAPS, are BG values sent as mg/dl or mmol/L

[shoaib42]

Hi folks, hope someone can help me here. I'm trying to understand what unit is used when xdrip sends the BG values to AAPS. Is it always in mg/dl even if the user uses the mmol/L units? "Send Display Glucose" tells me that its going to be mmol/L, (which I'm using) but the data stored in mongodb on NS suggests that mg/dL was received without any conversion.

I see sgv entries in mongodb with values in mg/dl that cannot be obtained by multiplying either 18 or 18.0182, no matter what kind of round or int conversion is used.

I checked the docs and the discussions here and I couldn't find my answer. What I'd like to have is that xdrip sends mg/dl values, given its higher graduation than mmol/L.

Thanks!

[Navid200]

As far as I know, everything is done in mg/dL.
The only time xDrip may intervene and convert to (from) mmol/L is when:
1- It is displaying a value on the screen and the user has chosen mmol/L as their unit of choice.
2- The user is entering a glucose value (for example, when calibrating) and they have chosen mmol/L as their unit of choice.

All calculations are done in mg/dL. All values are stored in the database in mg/dL.
And, as I said, as far as I know, everything is broadcasted in mg/dL.

Now, you are making a valid observation with respect to the "Send Display Glucose" setting.
That setting is not a distinction between mg/dL and mmol/L. It is rather a distinction between the real value and a smoothed out value with respect to noise. It is a mistake in my opinion to have this option in xDrip! And you can see more about my opinion in that sense here: #3866

Regardless of all of that, I am 90% sure the values broadcasted to AAPS are in mg/dL.

[shoaib42]

I went through the code and did find exactly that. The broadcast is done in mg/dl and the mmol conversion is done only for display. The thing that started the confusion was the wording "Send Display Glucose", if the display unit is mmol/L the user will assume that the inter app broadcast is being done in mmol/L while in reality it is mg/dL. While "Send Display Glucose" as you mentioned is the real value (according to the code whatever is stored in calculated_value).

Would it be good to have this at least in the doc or the app, saying something like this "The inter-app broadcast is done in mg/dL regardless of your unit of choice".

@Navid200 I did a quick read on the issue you pointed to. I'm new to the xDrip+ app. I'd add one thing though, why LPF, and not Kalman filter, for a smoother extrapolation? (I'm months away before I can make a proper contribution to the app).

[Navid200]

If you look at the summary of the setting, it says "Use noise smoothing ...".
It says nothing about the unit. I think it is ok as is.

Regardless of what protocol you use for the filter, there is no way to attenuate a sudden deviation without adding delay.