nRF8001 DateCredits and Packets per Connection Interval

[Leo Xu]

I am working on a project that uses PIC18 and nRF8001. PIC18 is used to control nRF8001 and LCD. The project needs to transmit large data to central ( about 512KB). It seems that the uploading took too long, estimated about 18 minutes ( Uploading 64KB took about 2 minutes). The DeviceStarted event returns DataCredits is 2. Does this mean 2 packets can be sent in one connection event? Connection interval min is 15ms, max is set to 30ms. Connected to IOS10, returned Connection Interval is 30ms ( Connected to nRF Connect app). Using nRF Snifffer captured packets, and the timing was confusing. From the capture, does it show:

1. What is the actual connection interval?
2. number of packets sent in one connection event?
3. There are a lot of Empty PDU between peripheral and central. What does it tell?

I attach wireshark capture here in csv file and screenshot. Right now, I am at the critical moment on the project.

Thanks a lot.

Leo wireshark_capture_02.csv wireshark_capture_scrrenshot_02.png.pdf

[Hung Bui]

@LeoXu: can you export the full wireshark log as .pcapng file ?

There are some threads you can have a look, here, or here.

You had some empty PDU, could be that you weren't queuing packets fast enough.