Regarding BLE advertising packet's transferring time on nrf52840

RE: Regarding BLE advertising packet's transferring time on nrf52840

tesc — Wed, 12 Feb 2020 16:45:22 GMT

Hi,

I am not sure if I understand.

You can get timestamps on logs, which means you can get a timestamp from locations in code. You cannot however get accurate timestamps from when the BLE stack (that is the SoftDevice) sends packets. You can get a timestamps from the callback function after having received an advertisement.

What timings do you need to measure, and with what accuracy?

A different way to get measurements like that may be use a BLE sniffer, such as the nRF Sniffer.

Regards,
Terje

RE: Regarding BLE advertising packet's transferring time on nrf52840

Thinking_HyunSoo — Mon, 10 Feb 2020 05:00:35 GMT

Thanks for replying.

So then can i make time logs whenever i send advertising packet from peri to central beacon?

I want to measure the time whenever peripheral beacon sends the advertising packet to the central one while they are connected.

I'm try to analyze the code on peripheral beacon, but i feel like i'm stock.

RE: Regarding BLE advertising packet's transferring time on nrf52840

tesc — Thu, 06 Feb 2020 15:29:53 GMT

Hi,

The logger module allows for configuring logs to be time stamped. You will see that for the project you are running, in main.c, the logger module is initialized with the line "ret_code_t err_code = NRF_LOG_INIT(app_timer_cnt_get);". The NRF_LOG_INIT() macro takes a function as an argument, and that function is the function that provides the timestamps. app_timer_cnt_get() is from the app timer library. This is not a Real Time Clock (RTC). We do have something named RTC on our SoC, but that is a "Real Time Counter". It is basically a low-frequency timer that can be used by e.g. real time operating systems, or any other purpose that needs a slower, but less power consuming, timer. In fact the application timer library uses the RTC (that is, the Real Time Counter), but as it is not a Real Time Clock it only gives the amount of time that has passed since enabling the library.

Regards,
Terje