Advertising services

[swathi p]

Hi,

I have to use current time service and one other customized service in my project.I am able to advertise only one service i.e customized one.can you please let me know the cause that might stop current time service from advertising?Below is the code attached

Thanks & Regards,

Swathi P

[Joakim Jakobsen]

Hi.

Are you sure that you have space to put both services int he avertising packet? Note that you only have 31 bytes available in the advertising packet.

You might want to place one of the services in the Scan response packet. The ble_app_uart example shows how this can be done.

Br,
Joakim

[swathi p]

Hi,

Thanks for your reply.As you suggested I have included one service in advertising packet and the other service in scan response packet.I am able to advertise two vendor UUID's.

Now,I am unable to advertise more than two vendor UUID's.I want to advertise one or two Standard BLE Services along with five manufacturer specific services.

I am getting an ERROR 12  [NRF_ERROR_DATA_SIZE] from ble_advertising_init().

After going through similar posts on devzone,got some suggestions to add  uuids_more_available or p_tx_power_level in advertising_init?what those variables exactly mean?

Can you please let me know the way I can make it possible?

Thanks & Regards,

Swathi P

[Joakim Jakobsen]

Hi.

As I mentioned there are only 31 bytes available in your advertising packet. With the required headers and flags, you are left with 29 bytes of data. 

The 128-bit UUID will use 16 of those bytes so there isn't possible to advertise two in the same advertising packet. Even with the scan response packet, you only have room for two in total.
One option could be to look at extended advertising. If you really need to advertise all the UUID's,  EA allows you to advertise up to 255 bytes.

Br,
Joakim

[swathi p]

Hi,

Thank you for suggestion.I will try implementing using extended adverisement.Can you please let me know any example where this extension advertisement is used?

Thanks & Regards,

Swathi P

[Joakim Jakobsen]

You can take a look at the ble_app_rscs example. This has EA enabled by default.

Br,
Joakim

[swathi p]

Hi,

I have tried implementing extended advertising by adding the below statements into the code:

  ble_advertising_init_t init;

init.config.ble_adv_primary_phy = BLE_GAP_PHY_1MBPS;
init.config.ble_adv_secondary_phy = BLE_GAP_PHY_2MBPS;
init.config.ble_adv_extended_enabled = true;

But after adding those statements i.e after enabling EA I am unable to Scan on nRF Connect.?And I have seen the same with ble_app_rscs example.Please let me know the way I can be able to scan on nRF Connect.

Thanks & Regards,

Swathi P.

[swathi p]

Hi,

After posting reply that I was unable to scan services in nRF Connect,after enabling EA.I have went through several posts related on same issue but I coudn't find any appropriate answer.I read few posts saying that it is due to bluetooth version in the android may not be supporting EA.I am using OPPO A71 to test.Is it true?

If yes,then please let me know the way in which I will be able to advertise and scan more than two vendor UUIDs.

Thanks & Regards,

Swathi P

[Joakim Jakobsen]

Yes, that is most likely due to the Phone not supporting AE.

If you are unable to use AE, there is no way to advertise more than two vendor UUIDs simultaniously. Then you have to advertise a vendor UUID, stop advertising, update your advertising packet with another UUID and start advertising again.

Br,
Joakim