A BLE disconnection issue occurred randomly after the device had been functioning without any problems for many hours

[Tai]

Hi everyone,

We have devices using the BLE module (nRF52) deployed in clinics for testing. They have been functioning without issues until recently when we noticed occasional BLE disconnections. The following image shows data from one of the affected devices. Its RSSI value dropped significantly to -90 dBm, indicating weak BLE signal strength that could explain the disconnect. However, the device was positioned close to a tablet running the application connected to it, where the BLE signal strength should have remained strong. This inconsistency is what we find puzzling.

In another case, the RSSI value was within acceptable range (-68dBm), which couldn't lead to the BLE disconnection. 

We're thinking of if any issue with code optimization. Any suggestions to further investigate this issue would be greatly appreciated. Thanks!

[hmolesworth]

We had a similar issue with a disconnect due to RSSI when the sensor was supposed to be next to a tablet/gateway and it turned out to be a large body of water placed in close proximity to the tablet ie someone picked the tablet up and turned away from the sensor to better read the data and the human body blocked the 2.4GHz signal pretty well. 2nd case looks odd though unless a local microwave got switched on .. SDK or nRFConnect?