nrf52840 slow rx characteristic time

RE: nrf52840 slow rx characteristic time

Simonr — Tue, 19 Nov 2019 14:04:40 GMT

You should measure from the first Empty PDU in the sniffer trace until the packet you want to compare in order to get the most reliable timing.

Best regards,

Simon

RE: nrf52840 slow rx characteristic time

_maibi — Tue, 19 Nov 2019 09:06:56 GMT

What is the connection confirm response message for connect request?

As you say, I compare different packets.

RE: nrf52840 slow rx characteristic time

Simonr — Mon, 18 Nov 2019 09:35:05 GMT

You've used two completely different "connected packets" when measuring the time here.

If you use the same packet, say the CONNECT_REQ packet in both instances, the times will be:

nRF51822_Galaxy_Note_4: 2.227 - 0.8359 = 1.39s

nRF52840_Galaxy_Note_4: 2.392 - 0.8065 = 1.58s

This is a very short time, and can not be counted as a delay. Furthermore, the time we see on the left side of the sniffer log is the time it takes for the computer to see the logs, so to be even more accurate, we should calculate the delta time (µs start to start) for each event to get the exact timing.

Best regards,

Simon

RE: nrf52840 slow rx characteristic time

_maibi — Mon, 18 Nov 2019 01:53:15 GMT

I tried to setting NRF_LOG_DEFERRED to 0 in the nRF52840 application. but, the result is same.

There are differences in nrf51822-galaxy-note4 and nrf52840-galaxy-note4.

the connected packet

nrf51822-galaxy-note4 - number: 66 time: 1.365

nrf52840-galaxy-note4 - number: 51 time: 0.807

the first packet in application

nrf51822-galaxy-note4 - number: 138 time: 2.227

nrf52840-galaxy-note4 - number: 156 time: 2.392

I'm not sure of the connected packet. Assuming it's right,

from the connected packet to the first packet in application

nrf51822-galaxy-note4 - number: 138-66=72 time: 2.227-1.365=0.862

nrf52840-galaxy-note4 - number: 156-51=105 time: 2.392-0.807=1.565

It's similar to android log time.

RE: nrf52840 slow rx characteristic time

Simonr — Fri, 15 Nov 2019 14:04:57 GMT

I've looked at your sniffer traces, and according to the data that goes over the air, the time from connection to service discovered is just about the same in both instances. a few µs faster on the nRF52840 in the note10 log. And a few µs faster on the nRF51822 in the note4 log. But the difference is negligible, so this seems to be your logs taking longer to print on one side. Did you try setting NRF_LOG_DEFERRED to 0 in the nRF52840 application?

Best regards,

Simon

RE: nrf52840 slow rx characteristic time

_maibi — Fri, 15 Nov 2019 06:28:48 GMT

thanks to reply!

here are the logs.

devzone.nordicsemi.com/.../nrf51822_2D00_galaxy_2D00_note10.pcapng devzone.nordicsemi.com/.../nrf52840_2D00_galaxy_2D00_note4.pcapng devzone.nordicsemi.com/.../nrf52840_2D00_galaxy_2D00_note10.pcapng devzone.nordicsemi.com/.../nrf51822_2D00_galaxy_2D00_note4.pcapng

RE: nrf52840 slow rx characteristic time

Simonr — Thu, 14 Nov 2019 10:01:47 GMT

Okay, it seems I misunderstood the initial question. Sorry about that. This delay happens after the devices have connected, right? Can you provide a sniffer log so we can take a look at what happens? You can do this either by using an Ellisys sniffer (if you have one available) or by using an extra nRF52 DK and the nRF Sniffer to sniff the connection.

You can also try setting NRF_LOG_DEFERRED to 0 in order to minimize the delay from an event until it is printed, as the terminal log might not be the most reliable way to measure the time it takes to get a service.

Best regards,

Simon

RE: nrf52840 slow rx characteristic time

_maibi — Thu, 14 Nov 2019 01:40:48 GMT

galaxy note 4

It takes almost 1.1 sec.

It takes almost 0.3 sec.

*different phone, More recent model. galaxy note 10

It takes almost 0.5 sec.

It takes almost 0.8 sec.

note10 is faster than note4 in average time, but the pair of galaxy note 4 & nrf51 is fastest speed to discover service.

and nrf52 is slow for all. Is it normal?

RE: nrf52840 slow rx characteristic time

_maibi — Wed, 13 Nov 2019 14:08:58 GMT

... I did double check. connection parameter is same.... and I tested ble app uart example in sdk. It also takes 1 sec. I think that there are big different nrf51 and nrf52. for now I dont have idea. parameter... or etc...

RE: nrf52840 slow rx characteristic time

Simonr — Wed, 13 Nov 2019 13:44:17 GMT

I believe this might be due to different connection parameters (intervals, etc.) in the two SDKs. I think this was done to minimize the current consumption, which causes events to be a bit longer. You can try setting the same connection parameters for both devices and compare, to see if this is correct.

Best regards,

Simon