CC2652R: Double Broadcasts' Enabling Interval

Katherine Wang

Part Number: CC2652R
Other Parts Discussed in Thread: SYSCONFIG, ENERGYTRACE

Hi Team,

1. I created my own 10ms task, enabled double broadcasts through the following interface, and set the enabling interval between the two broadcasts as 30ms. But through the packet capture tool, it could be seen that the interval between the two broadcasts was changing. Can I control the broadcasts' enabling interval in this way? If not, is there an API that can control the two broadcasts' enabling interval?

static void AdSwitch (uint8* pflag )
{
static uint8 cnt =0;
if (* pflag ==0)
{

GapAdv _ enable ( advHandlegacy , GAP _ ADV _ ENABLE _ OPTIONS _ USE MAX ,0);
cnt =1;
* pflag =1;
}
if ( cnt >=4)
{
GapAdv _ enable ( advHandle , GAP _ ADV _ ENABLE _ OPTIONS _ USE _ MAX ,0);
cnt =0;
}
else if ( cnt >=1)
{
cnt ++;
}
}

2. I turned on scanning in double broadcasting mode. If I don’t control the start time of broadcasting and scanning, will there be any conflicts between scanning and broadcasting? If so, is there a corresponding API interface to control this interval?

3. Can double broadcasting and scanning work well in sleep mode? How much is the power consumption in this case?

Kind regards,

Katherine

over 3 years ago

0 Clément over 3 years ago

TI__Guru** 101490 points

Hi Katherine,

1- Can you explain what you want to achieve?
The Bluetooth stack can handle on its own the advertising set, this means, there is no need the application attempts to enable the advertising every 10 ms.
Please refer to https://dev.ti.com/tirex/content/simplelink_academy_cc13xx_cc26xxsdk_6_40_00_00/modules/ble5stack/ble_scan_adv_basic/ble_scan_adv_basic.html
Please also note the advertising sets can be setup by SysConfig.

2- The radio can either receive, or transmit at a given time. However, the scheduler included in the Bluetooth stack is made to handle transition from broadcasting to scanning operations.
I recommend you enable the RF observables, so you can see when the device is receiving / transmitting. (see https://software-dl.ti.com/simplelink/esd/simplelink_cc13xx_cc26xx_sdk/6.40.00.13/exports/docs/ble5stack/ble_user_guide/html/ble-stack-5.x-guide/debugging-index.html#debugging-rf-output).

3- The power driver makes sure the device is set in the most optimized power mode. It ensures the device is waken up whenever needed.
You can estimate the power consumption running using EnergyTrace https://software-dl.ti.com/simplelink/esd/simplelink_cc13xx_cc26xx_sdk/6.40.00.13/exports/docs/ble5stack/ble_user_guide/html/energy-trace/energy-trace.html

I hope this will help,

Best regards,

0 Katherine Wang over 3 years ago

TI__Intellectual 2210 points

Hi Clément,

For the first question, I'm not enabling it every 10ms. I only enable it once with an interval of 30ms between two broadcasts. Secondly, after I enabled it in this way, I found through capturing packets that the interval between the two broadcasts changed instead of remaining at 30ms as expected. The cycle of each broadcast was 100ms. I checked the link you provided, but the switching interval between the two broadcasts was also changing after I enabled it in this way. How should I solve this?

The goals I'd like to achieve:

I hope to enable broadcast 1 at time 0 and enable broadcast 2 after 30ms. I only need to enable once. Only when the connection is disconnected will I enable again, and this mode will still be maintained. I hope to see two broadcasts through capturing packets. The interval between broadcasts is 30ms, and the single off-broadcast cycle remains unchanged at 100ms. Can this scheme be realized through the timer? If not, how should it be controlled?

I notice that the single cycle of each broadcast isn't exactly 100MS, so what is the deviation range of this broadcast cycle? If a fixed interval is not set, can the hardware resource allocation be well achieved when switching between double broadcasts? Will there be only one broadcast left after a while? Thanks

Kind regards,

Katherine

+1 Clément over 3 years ago in reply to Katherine Wang

TI__Guru** 101490 points

Hi Katherine,

Thank you for the details provided.

You cannot chose the exact duration between two advertising sets for at least two reasons:

- the stack sets the anchor point of each advertising taking a lot of parameters into considerations, in order to avoid collisions and spare air time.

- by specifications, a pseudo-random delay (0-10 ms) is added to the advertising interval (see BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 6, Part B, §4.4.2.2.1)

I hope this will help,

Best regards,

0 Katherine Wang over 3 years ago in reply to Clément

TI__Intellectual 2210 points

Hi Clément,

Thank you very much, and the issue has been resolved. But the original poster has one last query.

If there are both broadcasting and scanning, will there be any abnormalities when scanning and broadcasting are turned on at the same time? And if so, how could he deal with it?

Regards,

Katherine

0 Clément over 3 years ago in reply to Katherine Wang

TI__Guru** 101490 points

Hi Katherine,

Katherine Wang said:
If there are both broadcasting and scanning, will there be any abnormalities when scanning and broadcasting are turned on at the same time? And if so, how could he deal with it?

The scheduler will handle this and interrupt scanning when an advertisement has to be sent.

So no issue to expect on this side :)

Best regards,

0 Katherine Wang over 3 years ago in reply to Clément

TI__Intellectual 2210 points

Hi Clément,

In the multi_role_lin project, when I use it as a master-slave, I can’t find the function interface to automatically initiate the connection after the MR_EVT_ADV_REPORT event is generated after the scan is turned on. Is there a demonstration of the scan in this project? Thank you.

Regards,

Katherine

0 Clément over 3 years ago in reply to Katherine Wang

TI__Guru** 101490 points

Hi Katherine,

Please open a new thread for this question.

Thank you for your comprehension,

Best regards,

Bluetooth®︎

Bluetooth forum

CC2652R: Double Broadcasts' Enabling Interval