Channel hopping on 802.15.4 with nRF5 SDK 15.2

RE: Channel hopping on 802.15.4 with nRF5 SDK 15.2

AndreasF — Mon, 13 May 2019 10:12:03 GMT

Hi.

You could try to implement an Application timer, just look at this tutorial.

I don't think there is any available implementation of TSCH for nRF52 unfortunately.

Best regards,

Andreas

RE: Channel hopping on 802.15.4 with nRF5 SDK 15.2

Unknown — Fri, 10 May 2019 15:43:31 GMT

Thanks for the response.Adding 'sys_task_run()' inside the for-loop yet didn't solve the issue.

The modification I did is -

for(i=0;i<3;i++)
	  {
        nrf_delay_ms(2000);
		pib_set_get_request(gen_pib_id_t_plme( PHY_CURRENT_CHANNEL_ID ), &channels[i]);
        sys_task_run();
	  }

This is again giving 0xe1 as the scan return status

I also tried adding 'sys_task_run()' in a loop as shown below -

for(i=0;i<3;i++)
	  {
        nrf_delay_ms(2000);
		pib_set_get_request(gen_pib_id_t_plme( PHY_CURRENT_CHANNEL_ID ), &channels[i]);
        while(true)
        {
            sys_task_run();
        }
	  }

With the above modification , the for-loop is executing only once i.e there is no looping back.

'To implement channel hopping I suggest to use TSCH from 802.15.4-2015' - Is there any implementation of TSCH available based on 802.15.4 stack ? I have checked the zigbee SDK but i did not find it useful.

One other question - On transmission of every beacon is there any status parameter which gets set ?

RE: Channel hopping on 802.15.4 with nRF5 SDK 15.2

AndreasF — Fri, 10 May 2019 10:59:06 GMT

Hi again.

The problem is that in the main() function there is initialization of 802.15.4 followed by two loops

802.15.4 PHY/MAC requires to call `sys_task_run()` often after it is initialized, and it is correctly executed in the while loop, but the for-loop delays calls to `sys_task_run()` for several hundreds miliseconds or seconds, which causes problems. If `sys_task_run()` is not called, no beacon frames are transmitted. That's why just increasing delay in the for loop did not help.

[quote]

And is there a way to send only one beacon ? If yes , how can I do it ?

[/quote]

The only way I know is to receive beacon request - it cannot be forced by the application. Single beacon may be transmitted with the 802.15.4 driver from GitHub. But this driver lacks many functionalities of 802.15.4 PHY/MAC from SDK like maintaining PANs.

Moreover, beacon-enabled PANs in 802.15.4-2006 are not designed for channel hopping. To implement channel hopping I suggest to use TSCH from 802.15.4-2015.

Best regards,

Andreas

RE: Channel hopping on 802.15.4 with nRF5 SDK 15.2

Unknown — Wed, 08 May 2019 14:50:25 GMT

I changed the delay from 100 ms to 2 seconds. Now, scan on channel 20 is returning the mac scan status as 0xe1 which means channel access failure

And is there a way to send only one beacon ? If yes , how can I do it ?

RE: Channel hopping on 802.15.4 with nRF5 SDK 15.2

AndreasF — Wed, 08 May 2019 13:43:02 GMT

Hi.

The issue you have is that BEACON_ORDER is set to 2 seconds, and you change channels every 100 ms in your for-loop.

So you change from channel 20 to channel 14, and back to channel 20 before you send next beacon.

Best regards,

Andreas