mmol/L mg/dL

Juggluco for Wear OS

Juggluco for WearOS
Watch face with one complication
Watch face with three complications
Watch face with four complications

Juggluco is now ported to Wear OS. It consists of an adaptation of the smartphone version to the smaller screen of the watch and a watch face that shows the time, the current glucose value received every minute and four complication slots.

Left menu of Juggluco Wear
Right menu of Juggluco Wear
Watch face with one complication and music playing
Juggluco Wear

Every sensor has to be initialized by the smartphone version of Juggluco, that sends the sensor data to the watch version. Thereafter, there are two possibilities:

Specify glucose alarms
Specify ringtone

Exact instructions on how to get the watch working is given in the Smartphone version of Juggluco under Left menu-> watch-> Wearos Config -> Help.  The same text plus some pictures is given here.

Watch-sensor connection

A direct watch-sensor connection has generally more connection errors than a direct connection between a good phone and sensor.


Under certain circumstances Watch4 has more status=133 connection errors than others. They happen more often during a walk through the neighborhood and during indoor sport. I first thought that it was because of movement: perhaps Watch4 was programmed to do something while you are active like automatically detecting the activity and that somehow also turned off the Bluetooth connection with the sensor, maybe to support other Bluetooth devices like fitness equipment. The fact that more than half of the Freestyle Libre 2 sensors and nearly all Freestyle Libre 3 sensors had no problems with these movements, speaks against this. I have read somewhere that Bluetooth devices operate at wave lengths where there is a lot of activity of other devices, and that they do a lot of work searching for a free space between all these interfering waves of other devices. Maybe it is more difficult to find such a free space when the surrounding waves change more. Thus all the other people and houses full off devices transmitting waves that I pass while walking is the problem. The Bluetooth chip in my smartphone is somehow much better, and the signal of some Freestyle Libre 2 sensors and nearly all Freestyle Libre 3 sensors stronger, so that the don't have these problems.

Watch-phone connection

Connecting the sensor indirectly with the watch should always be possible. Sometimes there are general disconnection problems between phone and watch: The android companion app can't connect with the Watch. This can often be solved by rebooting the phone. Another method is to find Bluetooth in the list of apps (including system apps) in Android settings on your phone and press Clear Data.

After switching connection or returning after getting out of reach, the new connection is sometimes not immediately recognized. You can make it recognized by switching Wi-FI, Mobile Data or Bluetooth OFF-and-ON on the phone.

Download Juggluco

What to do when Juggluco on the watch stops receiving data from Juggluco on the phone?

On Watch connection with phone top
On Watch connection with phone middle
On Watch connection with phone bottom

See that Direct sensor-watch connection is turned off in the phone Left menu->Watch->Wearos Config.

First of all turn Bluetooth On in both watch and phone. Then switch WIFI off and on in one of them, if that doesn't work, try the other or try the same a second time (Turning Bluetooth off and on can also be effective if tcp is redirected through Bluetooth.) Also switching from Mobile data to WIFI or the other way around can help. Sometimes it only works with WIFI turned on on the phone and WIFI in the watch Juggluco's mirror screen checked. This means that the Bluetooth connection between watch and phone doesn't work. Sometimes force closing and restarting the Watch Companion app (for example Galaxy Wearable) helps, sometimes rebooting phone or watch or Clearing data of the Bluetooth system app helps.

Now my new phone (Qualcomm SM8350 Snapdragon 888 5G , Octa-core: 1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55, 8GB RAM) has given up and I have to use my previous phone (Mediatek MT6757, Octa-core 4x2.3 GHz Cortex-A53 & 4x1.6 GHz Cortex-A53, 3GB RAM) I have much more connection problems that seems to be cause by TCP over Bluetooth not working. WIFI OFF and ON, switching to mobile data or WIFI, re-init and sync all have no effect. But things like starting the Galaxy Wearable app, forced closing and starting that app, clearing the data of the Bluetooth app and rebooting phone and/or watch help to regain the TCP connection again for some time. Maybe the Galaxy Wearable app is stopped, although I gave both the Galaxy Wearable app and Galaxy watch4 Manager a power-saving exception. Maybe giving the Bluetooth system app a power-saving exception helps.

It is possible that the connection between Juggluco's on watch and phone doesn't work, because it was changed, therefore some screenshots are shown here of a functioning connection. The shown IP is automatically determined and exchanged via Bluetooth and don't need to be specified manually. The label is a watch identifier also shown in Watch->Wearos Config.

If in someway the connection settings are changed and you don't know what they were before, you can remove all connections you have not created yourself from Mirror in watch and phone and press on Init watch app. This has practically the same effect as reinstalling the watch app. If you reinstall Juggluco on your watch, you should also remove existing connections. You remove a connection by going to Left-middle menu-> Mirror on you phone or Left menu-> mirror on the watch, touching the connection and pressing Delete.

It is very important that always enough storage space is available. If at a critical moment the device is out of storage space, it is possible that the some files are not created the right way and you have to reinstall Juggluco again with enough storage space.

Phone connection with watch


If after scrutinizing these instructions, you still can't get Juggluco on the watch to work, send an E-Mail to containing:

Starting a new Sensor

(US-like sensors always need to be started with the Libre 2 app, thereafter do the same as described hereunder.)

When "Direct sensor-watch connection" is turned OFF, everything should be the same as when no watch is connected to the smartphone.

With "Direct sensor-watch connection" ON you should scan the sensor a few times. After warm-up period, the watch should get a Bluetooth connection with the sensor. Sometimes some more scans are needed after the warm-up period. Sometimes this isn't enough, then restarting Juggluco on the watch, by force closing it and starting it again, may help. If this doesn't work, you can turn OFF "Direct sensor-watch connection" and try it that way. Thereafter you can turn "Direct sensor-watch connection" ON again.

Watchface difficulties

Sometimes after an update of Juggluco, the appearance of the watch face has changed without any change in the program. For example the complications are not displayed. Changing to another watch face and back, let to the reappearance of the complications, but now lines appeared around the complications. Changing the color in the Watch face in the Watch companion app, led to the disappearance of these lines.

Allow background activity

Previously it was impossible turn on "Allow background activity" for Juggluco on Watch4, but after an update it is possible and it has also become necessary. If you don't turn it on Juggluco will be killed after some time.

On Watch4 you can turn on "Allow background activity", in the Galaxy Wearable, Watch Settings->Apps->Juggluco.