Example code for automatically reconnecting

sonalideo · October 2015

Hi.

Is there any full example code for Android on how to reconnect automatically to the device and resume operation, with full serialization/deserialization?

For example, if the device goes out of range, disconnects and then comes close again it should connect. Or even better in the mwBoard class add a reconnect automatically option.

I tried some basic reconnecting every minute on a device not in range but after a while I then get:

java.lang.NullPointerException

10-15 14:05:23.066 28761-32343/? E/AndroidRuntime: at com.mbientlab.metawear.MetaWearBleService$DefaultMetaWearBoardAndroidImpl.close(MetaWearBleService.java:659)

10-15 14:05:23.066 28761-32343/? E/AndroidRuntime: at com.mbientlab.metawear.MetaWearBleService$DefaultMetaWearBoardAndroidImpl.connect(MetaWearBleService.java:673)

Eric · October 2015

You can use the callback functions provided by the ConnectionStateHandler class to . Serialization is only needed if the board and app state are out of sync, which should not happen on a simple disconnect.

https://github.com/mbientlab/Metawear-SampleAndroidApp/blob/3.1.0/app/src/main/java/com/mbientlab/metawear/app/NavigationActivity.java#L143

KingTalullah · March 2016

How would you do this in iOS? If a device goes out of range, I would like the app to attempt to reconnect to it every 1 minute or so.

stephen · March 2016

The state property is KVO compliant, so after you connect to the device attach an observer and whenever it changes to disconnected, you can call connectWithHandler again.

Take a look at the sample app code here: https://github.com/mbientlab/Metawear-SampleiOSApp/blob/master/MetaWearApiTest/DeviceDetailViewController.m#L305

That will give you an idea of how to use KVO if you are unfamiliar!

Note, that a call to connect and persist indefinitely, so you don't need to keep calling reconnect every minute. Whenever it comes back it to range you will get a callback indicating connecting was successful

Example code for automatically reconnecting

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