how is Gzp pair (nRF52 with nRF24) distance

[Chaw]

Hi, Nordic nRF52 as GZP Device, nRF24 as GZP Host

I know if nRF52 is range of nRF24, the pair will be worked.

I want to know what is the distance.

And if I use unencrypt, I only want to pair two nRF52, how to disable 3rd nRF52 Device?

Gazell can not operate pair, right?

[ovrebekk]

Hi

There is a proximity pairing feature in GZP whereby a pairing request will only be accepted if the signal strength is above a certain value. In the nRF24 hosts this is implemented using the Received Power Detect (RPD) bit, which kicks in when an incoming signal is stronger than -64dBm. Exactly what range this equals is hard to predict, and can change depending on environmental factors, the hardware used and so forth, but I would expect the pairing range to be less than 1m.

If you close the pairing pipe after two devices are connected you should be able to limit the host to only support those two.

I don't understand what you mean with "Gazell can not operate pair". Could you elaborate?

Best regards
Torbjørn

[Chaw]

Thanks for your reply.

I know GZP is the Gazell pair library. If I only use Gazell like example in SDK, it do not inlude pair library, right?

[ovrebekk]

You are correct. GZP is just an extra module that you can use on top of Gazell, but it is entirely optional. If you don't use GZP then Gazell will use a static address configuration, and you have to program the same address into both the device and the host. The other important feature in GZP is the encryption, which is not covered by Gazell either.

[Chaw]

Hi, if two nRF52 connected to nRF24 via GZP, how can I know which pipe every nRF52 should use to send data?

I see nrf_gzll_add_packet_to_tx_fifo or nrf_gzll_ok_to_add_packet_to_tx_fifo, they both need to write one pipe, they should not use same pipe, right? if yes, how can I know whichi pipe should be used on both nRF52?

[ovrebekk]

Hi. There is no system for assigning pipes dynamically, in our examples this is statically defined (for example, the keyboard always uses pipe 1, the mouse pipe 2, remote pipe 3 and so forth). Either you have to do the same, or implement some functionality on top of GZP to tell the devices what pipe to use (assigning a fixed pipe for this purpose).