I used the DA14531 as the central device and connected the Bluetooth scanner gun as a peripheral.
Below error code for your reference. It seems some packages not received.
Can you provide more information? Such as
1. the frequency of this error happened
2. Does it always happen after 40sec's connection time?
3. What the hardware board is, is an official EVK not, if not an official EVK, does the board calibrate?
4. Has there some 2.4G interfering signal?
Thank you for your reply!
About additional information is as follows：
yes，I replayed it three times, all for about 40 seconds
I'm not sure if it's EVK, may be it is "Kit pro". The model number of this machine is "Dialog PRO-DB 376-04-F" and "Dialog PRO-MB 376-18-B"
My environment has 2.4G wifi and other Bluetooth devices
When using a mobile phone, it can be seen that after the scanner gun is successfully connected, it will report an L2CAP packet of about 500 bytes from time to time. I am not sure whether this has any impact.
Some log files:
I capture the log of the scanner gun, the reason is empty PDU at the LL layer did not respond. The comparison test is as follows
1. phone(central) connect to scanner gun(peripheral):
After the connection is successful, the scan gun will keep sending empty pdu, and the mobile phone can also respond in time
2. da14531(central) connect to scanner gun(peripheral):
After the connection is successful, the scan gun will keep sending empty pdu, In the first 40 seconds, the empty pdu can be responded in time, but after 40 seconds, the empty pdu cannot be responded in time.
3. da14531(central) connect to printer(peripheral):
After a successful connection, the printer does not continue to send empty PDUs, so there is no LMP RSP TIMEOUT that causes disconnection problems.
Could you please check why the empty pdu is not responded in time？
The log is as follows：