DFU failed after GATT connected.

[Kenta Harada]

I met this issue on some Android devices. GATT connection is disconnected before before service discovery finished. The issue is reporeted in following link.

github.com/.../35

I'd like to know the workaround of this issue.

[Hung Bui]

Hi Kenta,

How often do you have the issue ? Do you have disconnection when you test with just nRFConnect (no DFU ) ?

Have you tried to do what Philips suggest by adding a delay ?

[Kenta Harada]

Thank you for your comment.

I don't use nRF Connect, use our original Android application with Android DFU Library. DFU Library waits some seconds before GATT connection but it's not enough on some Android devices. So I added a 1.5 sec delay before calling DfuServiceInitiator.start() (This is because we don't want to customize DFU Library). But disconnection happens on some Android devices such as KYOCERA, SHARP and FUJITSU.

[Hung Bui]

Please let me know do you have the issue with nRFConnect, just do a connection and don't do DFU. We need to check if it's the issue with DFU library or it's the issue with Android OS. How often do you see disconnection ?

[Kenta Harada]

I tried with following conditions.

Android App nRF Connect for Mobile 4.11.1 nRF Toolbox for BLE 2.4.0

Android Device F-02H(Fujitsu) Android Version : 5.1.1

BLE Device nRF52832, SDK 11.0.0, SoftDevice S132 v2.0.1

Result nRF Connect : DFU Finished successfully

nRF Toolbox : DFU Failed(Showed "DFU Process failed" in Notification message)

DFU finished successfully on nRF Connect! What's the differences between Connect and Toolbox??

I would like to check souce codes of nRF Connect. is that possible ?

[Hung Bui]

They are very similar as they both use the DFU library to do the task.

Have you tried to repeat the test several times just to make sure nRFConnect always work ?

A sniffer trace would be useful to see why a disconnection happened.