nRF52832‘s BT and 2.4G Private protocol

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Tue, 21 Dec 2021 08:28:48 GMT

Hi,

I will get back to you soon with the response. Kindly expect a delay since we are understaffed at the moment due to the Holiday season in Norway.

Regards,

Priyanka

RE: nRF52832‘s BT and 2.4G Private protocol

wudongdong — Tue, 21 Dec 2021 07:46:41 GMT

Does the nRF52832 support classic Bluetooth？If yes，how to set?

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Fri, 17 Dec 2021 11:06:08 GMT

Hi,

In case of additional support like a phone call, you should contact your Regional Sales Manager (RSM). I could provide you with some more details which can be of help. You can read about the basic details of packet transmission, radio and packet length from here.

So there is a transmitter and receiver and packets are sent and received on-air. Ideally without any packet loss, the latency depends on radio startup time and the time taken to send the packet on-air. There might also be the processing time of the RX to be considered.

Shown above is the basic structure of a packet. The radio startup time is typically 140us but is 40us in the fast startup mode. You can find more about these here.

As you can see from the basics earlier, there is the 1M mode and 2M mode. In the 1M mode, each bit takes 1us on air and in 2M mode, each bit takes 0.5us.

As for the processing time at the RX end, this could be around 10us or less before triggering the interrupt (this is not really documented).

Regarding other factors that affect the latency, there can be the time of flight (time which the packet is in air), which can vary depending on distance of transmission. But this won't affect much since this might add like 1us of delay for 300m or so. There can also be delays added by the TX and RX clocks which will have random phase as they are not synchronized. (this too is really small and negligible).

Regards,

Priyanka

RE: nRF52832‘s BT and 2.4G Private protocol

wudongdong — Fri, 17 Dec 2021 10:01:25 GMT

Can we talk over the phone so that we can communicate more thoroughly

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Fri, 17 Dec 2021 09:52:46 GMT

There are various factors, for example the 2.4GHz RF is affected easily by various objects like walls, furniture, people but sometimes this might not cause a huge difference as in homes, since there is reflection from the objects (but this cannot be relied on). Also, there can be other 2.4GHz sources which can cause interference like the WiFi etc.

-Priyanka

RE: nRF52832‘s BT and 2.4G Private protocol

wudongdong — Fri, 17 Dec 2021 09:46:33 GMT

If the environment is completely free of interference, what settings will affect the fluctuation of delay, and what factors will affect delay in addition to settings and environment.

Send the synchronization signal according to a certain frequency and do not retransmit whether the packet is lost or not. What is the delay and the fluctuation range?

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Fri, 17 Dec 2021 09:24:38 GMT

I am not sure you understand. We cannot give you a specific value since this depends entirely on your configuration, environment and many more. Also, when considering all factors, packet loss is not something that you can NOT consider. The latency depends on various factors and you will have to find this out yourself by real-life experiments. Hence, the fluctuation of the latency can be in a wide range or small range.

I hope you have obtained the answers to your query and in case of further queries, kindly open a new ticket.

-Priyanka

RE: nRF52832‘s BT and 2.4G Private protocol

wudongdong — Fri, 17 Dec 2021 01:36:06 GMT

If packet loss is not considered, No matter whether the packet is lost or not, it will not be retransmitted, can the latency be fixed? If fixed, what would the value be. In addition, what is the additional delay for a packet loss and then retransmit once?

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Thu, 16 Dec 2021 10:20:29 GMT

well, this depends a lot on various factors. Sometimes if you increase the range of transmission, there can be packet loss and this will in turn lead to a longer latency since you will have to re-transmit. This is not something that can be fixed, i.e. it totally depends on everything at your end for which you would have to do real-life testing (preferably for a worst case scenario and find what is your worst latency). So the range can be infinity 😃

RE: nRF52832‘s BT and 2.4G Private protocol

wudongdong — Thu, 16 Dec 2021 08:27:47 GMT

We use the 2.4G private protocol for signal synchronization. Suppose we achieve a delay of 0.5ms by setting. Can the 0.5ms delay remain stable for each transmission? If not, what is the fluctuation range?

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Wed, 15 Dec 2021 09:29:31 GMT

Hi,

There is no particular fluctuation range when it comes to the 2.4G private protocols since this depends on the way you set it and according to your needs. As for Bluetooth, you could try taking a look at Bluetooth 5

For an in depth detail related to Bluetooth 5, you could try contacting the Bluetooth forum.

Kind Regards,

Priyanka

RE: nRF52832‘s BT and 2.4G Private protocol

wudongdong — Wed, 15 Dec 2021 03:16:21 GMT

The Bluetooth latency can reduce to 1ms.and 2.4G private protocols's latency can reach 0.5ms.

Whether the latency is fixed？ What is the fluctuation range if it is not fixed

RE: nRF52832‘s BT and 2.4G Private protocol

Priyanka — Fri, 10 Dec 2021 13:10:12 GMT

Hi,

The Bluetooth latency can go down to 7.5ms normally, but there is also this LLPM feature which is a specialized proprietary Bluetooth extension in Nordic devices, used mainly for gaming mice which allows to reduce the latency up to 1ms.

As for the 2.4G private protocols this depends on your protocol. You can enable the radio and have delays as low as 0.5ms.

Kind Regards,

Priyanka