nrf Connect Device Manager Android application showing GATT ERROR.

[noob_123]

Hi,

Using nrf nrf Connect Device Manager Android application for DFU is resulting in GATT error. I am using Tes and Confirm option and it connects, upload the new image, show resetting status but after reset when it tries to connect back to the device to confirm it shows GATT Error. 
Can you help identifying the reason for this error?

Thank you 

[Hung Bui]

Hi Noob, 

GATT error (I assume with code 133 ? ) is a generic error and it can be that the connection was not established. So if the device take too long to boot up and advertise error will occurs. 

However from my point of view, it's not obligated that the phone app should re-connect to the device right after DFU update. It's because the swapping of the images on the chip may take a long time.
End user can choose to make a new connection after the device is updated or not. 

Have you tried to test with Confirm only ? It should be faster than test and confirm.