nRF51 DK Sniffer, nRF52 DK sniffer - timestamp measurement accuracy

[Ron]

Hi

What is the timestamp accuracy of the nRF51 DK based Sniffer, nRF52 DK based sniffer, 

I want to measure the actual accuracy of my advertisement interval, preferably to 1 microsecond level,

If the nr51DK and nrf52DK can not provide 1 microsecond accuracy, what tool what you recommend (nothing too expensive I hope)

Best regards

Ron

[Emil Lenngren]

There is microsecond resolution. In the metadata header of the packet from the sniffer, you can see packet start time and end time.

[Ron]

Thanks, yes, but accuracy and resolution are not always the same or similar

[Emil Lenngren]

It follows the accuracy of the HFXO of the devkit which I guess is something like 20 ppm.

[Ron]

Just to make sure, the time-stamp listed on the log, is derived from the devkit actual reception time, and not from system time, or communication time?

[Emil Lenngren]

If you open the "nRF Sniffer for Bluetooth LE", the "Timestamp" entry there is the correct one and the one you should use. You can right click on that one in Wireshark and you will find an option to use it as column in the list of packets. The other date/time columns might indicate the time the packet was received by the computer from the sniffer and hence slightly inaccurate. You can easily compare these with the raw Timestamp field to see if that is the case when you have at least two entries.