"Fast Advertising", "Slow Advertising", and indefinite advertising.

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

Vidar Berg — Thu, 25 Apr 2019 13:57:08 GMT

I'll forward your feedback to those responsible for the documentation, thanks.

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

awneil — Wed, 24 Apr 2019 13:51:49 GMT

Thanks.

Please can the documentation be updated to make this clear.

It would also be helpful to make the names more descriptive.

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

Vidar Berg — Wed, 24 Apr 2019 13:41:21 GMT

Yes, it's just for convenience and is optional to use. Apple recommends having both in their design guidelines: https://developer.apple.com/accessories/Accessory-Design-Guidelines.pdf (section 25.3)

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

Andy — Tue, 23 Apr 2019 14:02:35 GMT

Yes, that's actually how I found the documentation I linked above, but that's already in the GAP header file. I don't think there's any information about the timeouts in the header file of the advertising module.

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

awneil — Tue, 23 Apr 2019 13:59:33 GMT

[quote userid="15909" url="~/f/nordic-q-a/46515/fast-advertising-slow-advertising-and-indefinite-advertising/183141"]I don't think it's linked anywhere[/quote]

I eventually found this - in ble_gap.h:

/**@brief GAP advertising parameters. */
typedef struct
{
  :
  :
  uint16_t                 duration;                /**< Advertising duration in 10 ms units. When timeout is reached,
                                                         an event of type @ref BLE_GAP_EVT_ADV_SET_TERMINATED is raised.
                                                         @sa BLE_GAP_ADV_TIMEOUT_VALUES.
                                                         @note The SoftDevice will always complete at least one advertising
                                                               event even if the duration is set too low. */

The SES 'Find in Project' doesn't work on on that Doxygen cross-reference to BLE_GAP_ADV_TIMEOUT_VALUES, but some raw text searching does eventually get to:

/**@defgroup BLE_GAP_ADV_TIMEOUT_VALUES GAP Advertising timeout values in 10 ms units
 * @{ */
#define BLE_GAP_ADV_TIMEOUT_HIGH_DUTY_MAX     (128)   /**< Maximum high duty advertising time in 10 ms units. Corresponds to 1.28 s. */
#define BLE_GAP_ADV_TIMEOUT_LIMITED_MAX       (18000) /**< Maximum advertising time in 10 ms units corresponding to TGAP(lim_adv_timeout) = 180 s in limited discoverable mode. */
#define BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED (0)     /**< Unlimited advertising in general discoverable mode.
                                                           For high duty cycle advertising, this corresponds to @ref BLE_GAP_ADV_TIMEOUT_HIGH_DUTY_MAX. */
/**@} */

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

Andy — Tue, 23 Apr 2019 13:29:34 GMT

[quote userid="6462" url="~/f/nordic-q-a/46515/fast-advertising-slow-advertising-and-indefinite-advertising/183135"]But I can't see that mentioned or linked anywhere in the documentation of the slow or fast advertising parameters?[/quote]

Yeah I don't think it's linked anywhere.

[quote userid="6462" url="~/f/nordic-q-a/46515/fast-advertising-slow-advertising-and-indefinite-advertising/183135"]I've also seen it suggested that slow advertising is "low power" - but unclear if that's purely because it is slow[/quote]

I think so, it's purely because it's slow.

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

awneil — Tue, 23 Apr 2019 13:20:59 GMT

[quote userid="15909" url="~/f/nordic-q-a/46515/fast-advertising-slow-advertising-and-indefinite-advertising/183130"]As far as I know it's just a convenient featur[/quote]

Yes, that does seem to be the case.

It would be good to have an explicit statement - especially as it's used in the context of Directed advertising - which is something different.

I've also seen it suggested that slow advertising is "low power" - but unclear if that's purely because it is slow, or if there are other "special measures" to make it so ...

[quote userid="15909" url="~/f/nordic-q-a/46515/fast-advertising-slow-advertising-and-indefinite-advertising/183130"]With regards to the timeout value, you can find the documentation here[/quote]

Thanks.

But I can't see that mentioned or linked anywhere in the documentation of the slow or fast advertising parameters?

RE: "Fast Advertising", "Slow Advertising", and indefinite advertising.

Andy — Tue, 23 Apr 2019 13:09:50 GMT

As far as I know it's just a convenient feature. I actually extended that to support a "super slow" advertising interval after the slow advertising times out. I don't think it is a Bluetooth spec feature or anything like that.

With regards to the timeout value, you can find the documentation here.