Since the iOS13 release, connection problems between iPhone/iPad and the Truma iNet Box occur. In the meantime, we have been able to identify two different issues – but have not yet been able to solve the problems, even in cooperation with Apple support.
Here you can find a detailed error description and technical information about the causes of the problems. As soon as we have new findings, we will keep you up to date in the Truma service blog and in the App News.
Have you had experiences that you would like to share with other users and us? Then use the comment function in our service blog! We look forward to exchanging ideas with you.
iPhone 6s to iPhone XR (iOS13) / iPads (iPadOS13) – Connection problems
After three days at the latest, a Bluetooth connection to the Truma iNet Box can no longer be established. The blue LED lights up constantly, even without an active connection. Control is therefore no longer possible in the near field. In the far field, no LevelControl values can be called up via SMS. The error only occurs sporadically.
Each Bluetooth LE device has 40 Bluetooth channels, three of them are used as advertising channels. These are used to establish a connection between Bluetooth devices. To do this, the Bluetooth LE device sends short attentional messages via advertising signal on at least one of the three advertising channels. The device then waits for a connection request from another Bluetooth device. When the connection request is made, the devices switch to one of the remaining 37 channels to receive a larger block of data from the device.
Devices with iOS13 version send a constant advertising signal via Bluetooth. Even if the connection is already established, the app is active in background mode, is completely terminated or even uninstalled.
If no app is active while the Truma iNet Box is trying to establish the connection, the connection will fail. What otherwise works within a few seconds, is then resource-intensive for the Truma iNet Box, interferes with other connections or prevents the establishment of further connections with active Truma Apps (e.g. Truma LevelControl values are displayed with a long delay).
If the Truma app queries whether the advertising signal is being sent, it is informed that this is not the case. Although the functions provided by Apple in the interface have not changed with iOS13, they no longer work as desired since the update.
Restarting the Truma iNet Box will result in an improvement until the situation recurs. The best way to restart the Truma iNet Box is to disconnect it from the power supply.
Why do other Bluetooth devices work with iOS13, but not the Truma iNetBox?
The Truma iNetBox uses the iOS devices as “peripherals” and does so with one of the first Bluetooth protocol versions to support this. Although this configuration is very common, it is obviously not the focus of Apple’s test coverage.
Why was the problem not resolved during the beta phase of the iOS 13 updates?
The issue was revealed with the first iOS13 beta, but it quickly became clear that we were dependent on Apple to fix it. At the same time, we received a lot of feedback regarding misbehavior in other Bluetooth applications. Apple has now fixed most of the bugs – but unfortunately not the one concerning the Truma iNet Box.
What is being done to remedy the malfunction?
We are working hard to eliminate the malfunction together with Apple. In addition, we are also trying to influence Apple via the manufacturer of our Bluetooth chip and at least, work out a workaround.
What can I do if the error occurs?
The error occurs, if there are several iOS devices in the vicinity of the Truma iNet Box that have the Truma app installed but the app is not active.
You can do this:
1) Exit Truma App
2) Turn Bluetooth off and on again (in the settings and not via shortcut menu).
This temporarily stops the unwanted sending of the advertising signal and makes it easier for the Truma iNet Box to establish a connection with other iOS devices.
iPhone 11 – Connection problems
It is not possible to establish a new Bluetooth connection to the Truma iNet Box. The malfunction always occurs.
The connection between the Truma iNetBox and an iOS device is encrypted for security reasons. To this end, various keys are generated when the Truma iNetBox is set up, one of which is stored on the Truma iNet Box. This guarantees that a secure connection can be established immediately after the Truma iNet Box is set up.
Once the connection is re-established, the iPhone 11 does not respond to the encryption request and stops communicating with the Truma iNet Box. The problem occurs even though all Bluetooth specifications have been implemented correctly. The reason for this is a modified chipset that Apple uses in the iPhone 11 and is therefore not compatible with the Truma iNet Box.
A workaround is currently not possible. A factory reset of the Truma iNet Box only enables a one-time connection via Bluetooth, for example to set up Truma LevelControl and GSM.
Why does only the iPhone 11 not work with the Truma iNet Box?
Apple uses a different chipset in the iPhone 11 than in the previous models. Although all Bluetooth devices must undergo conformity tests, this chipset is not compatible with the Truma iNetBox.
Why don’t we just do without encryption?
Apple uses another security mechanism that does not work without encryption. An unencrypted connection would break off as soon as the iOS device randomly changes the Bluetooth address.
What can I do if the error occurs?
The error always occurs and there is currently no workaround. Only a factory reset of the Truma iNet Box, in which the Bluetooth button is pressed for 20 seconds, allows a one-time connection.