Hello Nordic Experts, Recently, I have been investigating the radio timing for advertising, I tried to find answers online, but I failed. To explain more clearly, let me give you an example, as you know, the radio needs to sniff the scan or connection request after each ADV_IND PDUs, which means the radio should switch from TX to RX, so my questions are as follows: as we all know, scan or connection request will be transmitted after 150us+-2us when the ADV_IND PDU has been sent on the 37,38,39 channels. so when the radio will switch to RX state after ADV_IND PDU has been sent? how long the radio will keep RX state when there are not any requests? how long the radio will keep RX state when there are scan or connection requests? in my understanding, when the radio checked the access address , it will consider the current request to be valid and then stop the Rx timeout timer until the remaining packets have been received and then check which types of requests? if not, can you explain the mechanism behind? thanks in advance.

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【nRF52840/Radio Timing】Radio Timing for Advertising

Hello Nordic Experts,

Recently, I have been investigating the radio timing for advertising, I tried to find answers online, but I failed. To explain more clearly, let me give you an example, as you know, the radio needs to sniff the scan or connection request after each ADV_IND PDUs, which means the radio should switch from TX to RX, so my questions are as follows:

as we all know, scan or connection request will be transmitted after 150us+-2us when the ADV_IND PDU has been sent on the 37,38,39 channels. so when the radio will switch to RX state after ADV_IND PDU has been sent?
how long the radio will keep RX state when there are not any requests?
how long the radio will keep RX state when there are scan or connection requests? in my understanding, when the radio checked the access address, it will consider the current request to be valid and then stop the Rx timeout timer until the remaining packets have been received and then check which types of requests? if not, can you explain the mechanism behind?

thanks in advance.

0 user15146 over 4 years ago

Hi,

1) Right after each TX, it will switch to RX, if it's doing connectable advertising.

2) Looking at the Online Power-profiler, around 60us

3) I don't know the implementation details, but yes, that sounds about right.
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0 user21601 over 4 years ago in reply to user15146

user15146 said:
1) Right after each TX, it will switch to RX, if it's doing connectable advertising.

as you mean, it will switch to RX right now after each TX?

user15146 said:
2) Looking at the Online Power-profiler, around 60us

Yes, I checked it before, but I want to know if there are any special requirements for it. In other words why the value is 60us, not other values? can you explain more about it?

user15146 said:
3) I don't know the implementation details, but yes, that sounds about right.

ok. so it is out of spec, and depending on the implementation of stack, May different chips, different implements? right?
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0 user15146 over 4 years ago in reply to user21601

as you know, the radio needs to sniff the scan or connection request after each ADV_IND PDUs
xiaolongba said:
I want to know if there are any special requirements for it.

What are you implementing? If you are looking for a sniffer solution, you can use the nRF sniffer: https://www.nordicsemi.com/Products/Development-tools/nRF-Sniffer-for-Bluetooth-LE
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0 user21601 over 4 years ago in reply to user15146

actually, I am writing BLE tutorials based on 52840 for my students, so I need more details as much as possible. so Sigurd bro, could you give me a hand?

thanks in advance.
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0 user15146 over 4 years ago in reply to user21601

There are some more info in the SoftDevice Specification

https://infocenter.nordicsemi.com/topic/sds_s112/SDS/s1xx/ble_processor_avail_interrupt_latency/ble_broadcaster_performance.html

https://infocenter.nordicsemi.com/topic/sds_s112/SDS/s1xx/ble_processor_avail_interrupt_latency/ble_peripheral_connection_performance.html
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