Gazell - Lots of failed to pair attempts

[DonaldInspiro]

Hello,

We are having problems with Gazell pairing. Both the host and the device are using the Gazell stack from the nRFgo SDK 2.3.0.10040 ported to run on an Atmel SAMD20J18 connected to an nRF24L01+.

During the pairing process, the negotiation of the host address fails a lot. When the host address is finally received, the process fails to get the host ID.
The strange thing is, that when pairing has succeeded, the encrypted commands are always send succesfully without fail. (which seems to indicate that sync and freq hopping works properly)

Pairing power has been set to max so distance between the devices (~10cm) should not be a problem.

Pairing requests are not always received in the host. If a pairing request is received by the host, it does not guarantee that the host address is received in the device.

Do you have any idea how we might improve the succesrate for pairing?
What Gazell parameters might we look into for tweaking?

Best regards,

Donald

[ovrebekk]

Hi

Do you have a way to verify how quickly the host is switching RF channels? 

The while function you point to is implementing a simple delay, that is dependent on the length of the RX timeslot. If the RX timeslot is longer than normal the delay would also be increased. 

Maybe you can scope the SPI control lines to see how often the RF frequency changes?

Best regards
Torbjørn

[DonaldInspiro]

Hello,

After scoping the SPI lines, it seems like the RF channel is switched every ~65ms.

Best regards,
Donald

[DonaldInspiro]

Hello Torbjørn,

After closer inspection of the gazell timer port, it turned out that the timer was initialized incorrectly. After proper initialization, the channel hopping is executed every 1ms and the pairing process now seems stable.

Thank you for your support.

Best regards,
Donald