is there anyway to reduce advertising interval on DFU

[makouda]

im using sdk10 softdevice 8.0.

on my app I configured #define APP_ADV_INTERVAL 1500 and I noticed that when I activate Dfu service (activate notification on last service and write), the DfuTarg advertise but it disconnect many times before a successful DFU programming. but when I set #define APP_ADV_INTERVAL 64 I success in my first attempt to program using DFU. in the SDK10\components\libraries\bootloader_dfu\dfu_transport_ble.c file, m_adv_params.interval is set to 0 my question is :

1 what's the mean of setting m_adv_params.interval to 0. minimal value required is 20.

2 where is the advertising interval for DfuTarg is configured? : on my app or on the bootlaoder

3 if the advertising interval is configured on my app, how can I change it to 32 just for the DFU service (I care much about battery life)

4 : if the advertising interval configuration is in the bootlaoder, where can I set it to min??

[Vidar Berg]

Hi,

Advertisment interval in bootloader mode can be set by redefining APP_ADV_INTERVAL in dfu_transport_ble.c. The adverisment interval used by your application doesn't affect the interval used by the bootloader.

Interval is only set to '0' when doing high duty cycle directed advertising; the radio transmits as many advertisement packets as possible during a 1.28 ms window.

[makouda]

so you mean that 0 is the min inteval possible????

[Vidar Berg]

No it's not possible to have zero interval on advertisements, but the value is not relevant when doing high duty cycle directed advertisement. You can find more details about directed advertisement in core spec. 4.2., vol 6, part B, section 4.4.2.4.2

[makouda]

but then having 0 APP_ADV_INTERVAL would make the connection to DfuTarg easier then having 20 ?? in fact this is my question in my comment

[Vidar Berg]

The bootloader needs to know the peer address in order to do directed advertising. In other words, peer data address must be present in the dfu_ble_peer_data_t structure located in the "noinit" section of RAM when doing "buttonless" DFU. Note that you need to use regular advertising with or without whitelisting when the peer address is private resolvable.