Gazell timeslot configuration: timeslot_period vs timeslots_per_channel

RE: Gazell timeslot configuration: timeslot_period vs timeslots_per_channel

Hung Bui — Thu, 01 Jun 2017 09:23:15 GMT

It's expected Andrew. As described in the documentation "By choosing the NRF_GZLL_DEVICE_CHANNEL_SELECTION_POLICY_USE_CURRENT policy, the Device sends on the channel it believes the Host is currently listening to. "

If the calculation on the device is correct, there shouldn't be any channel switches.

RE: Gazell timeslot configuration: timeslot_period vs timeslots_per_channel

Andrew Kohlsmith — Wed, 31 May 2017 18:22:57 GMT

Thank you, I think I understand. I've got a system set up now and it appears to be working. I have the device channel selection mode set to USE_CURRENT, but monitoring the tx_info .num_channel_switches value of the ACK packets coming back from the tx_success() callback, the value is always zero. Is this expected? The number of transmission attempts value varies between 1 and 3 (which is my max) and the RSSI value moves how I'd expect, but the number of channel switches is always zero.

RE: Gazell timeslot configuration: timeslot_period vs timeslots_per_channel

Hung Bui — Wed, 31 May 2017 11:43:42 GMT

Hi Andrew,

Q1. Yes, if you only have one device connect to the host. When you have more than one you should do what you described on having different channel table on each of the device and the grouped one on the host. And you can define the number of timeslot be doubled on the device so they won't collide . Have the look here, in the comment.

Q2. I would suggest to leave the timeslot at 600us on all devices, host, and only change the number of timeslot per channel. You don't need to double the timeslot period on the host. Please follow the example in the link above.