nrf52832 scan channel switch time

RE: nrf52832 scan channel switch time

loquat — Fri, 29 Sep 2017 23:16:44 GMT

thanks for comment. I confimed scanreserved on datasheet.

It is bad spec and very disappoint.

RE: nrf52832 scan channel switch time

bjorn-spockeli — Fri, 29 Sep 2017 14:19:22 GMT

It is correct that the nRF52832 is able to switch channel frequency much faster, as fast as 40us, see the Radio Timing section in the nRF52832 Product Specification.

However, the SoftDevice will reserve at least 760us after each each ScanWindow, refered to as tScanReserved in the S132 SoftDevice Specification. So the behaviour you're seeing is to be expected.

RE: nrf52832 scan channel switch time

loquat — Fri, 29 Sep 2017 08:32:45 GMT

I measured current consumption. execute sd_ble_gap_scan_start() by 5ms(0x08) interval/window.

It's interval is 5ms. switch time(off time) is 1ms.

RE: nrf52832 scan channel switch time

loquat — Fri, 29 Sep 2017 01:57:29 GMT

I tryed by TimeSlot API for scan.

result On 5ms channel switch interval, switch time is very fast(<200us)!!

I think, problem is SoftDevice's sd_ble_gap_scan_start().

RE: nrf52832 scan channel switch time

loquat — Thu, 28 Sep 2017 23:32:36 GMT

Thanks for comment.

I know that nRF52 recieve over 1000-adv per sec. But, I measured it on 100ms scan-interval. If change scan-interval to 5ms, how many receive advs?

I seem it to poor receiver.

RE: nrf52832 scan channel switch time

endnode — Thu, 28 Sep 2017 20:16:20 GMT

No, there are no signs that CSR chips would be superior to nRF52. I can only say that I've reached resolution of <2ms with nRF51 (meaning it registered >500 adv. packets per second) and I'm pretty sure that S132 stack on nRF52 should be in range of 500-1500 adv. events per second (at least). Note that during DTM chip is able to see one packet per 0.625ms without single failure. I'm afraid it's in your measurement set-up not in the chip (nor in the stack).

RE: nrf52832 scan channel switch time

loquat — Thu, 28 Sep 2017 13:32:29 GMT

yes.

I can not upload a analyzeing image. But It's cyclic a 5ms interval. and when change interval(10ms, 20ms, etc), interval is changed a setted interval, but switch time is about 1ms.

Also, I measure the recieve counts. interval:20ms 1500counts/minutes interval 5ms 450counts/minutes

Other case, I compare againest CSR BLE chip. CSR BLE chip is 1000countes/minutes on 5ms scan interval.

Is nrf52832 poor againest CSR BLE chip?

RE: nrf52832 scan channel switch time

endnode — Thu, 28 Sep 2017 11:27:50 GMT

Are you sure that peeks in the power consumption curve are really related to switching of Rx channel?