BLE connection takes long time with SDK17.1.0 example

[karanbakshi]

Hi,

I am currently evaluating BLE long range feature for one of the our product. for this, using two nRF52840 dongle PCA10059. One used for peripheral and another for central. Using SDK 17.1.0 examples and S140.

When central initiate connection with Peripheral, it takes random too much time for successful connection from 3mins to 10mins sometime after SUCCESS response from API sd_ble_gap_connect. Even if I disable PHY_CODED, facing same issue. what could be the reason?

Let me know if more info required for any configuration.

Regards,

Bipin Patel

[Simonr]

Hi

Just to make sure. Are you saying it takes more than 3 minues from NRF_SUCCESS until the Dongle connects to the other one? The connection supervision timeout should trigger way before that. Can you try any of the default examples (ble_app_uart and ble_app_uart_c for instance) in the SDK to check if you are able to connect within a reasonable timeframe there? It shouldn't take more than a few seconds from when they both are turned on. I have tested with Coded PHY myself and have not seen this amount of time for a connection to be initiated successfully.

Best regards,

Simon

[karanbakshi]

Hi Simonr,

Let me explain my advertisement logic here as I have observed one thing regarding it.

Peripheral device advertise interval is 2sec. With sample code, using stack advertisement function, there is not much delay in connection. it is connected within 10 second maximum.

But I am using timer based advertisement means running 2 second timer, on timer interrupt start advertisement, on radio notification event stops advertisement and start it again on next 2sec timer interrupt. set radio notification on NRF_RADIO_NOTIFICATION_TYPE_INT_ON_INACTIVE.

With this kind of advertisement, I am facing delay in connection via central. but with phone app as a central, it connects within some seconds.

I am following timer based advertisement because I am also controlling other iBeacon and Eddystone frames using same kind of timer and radio notification event.

Regards,

Bipin Patel

[Simonr]

Hi

karanbakshi said:

With this kind of advertisement, I am facing delay in connection via central.

I assume this is pointing to the Dongle central you're using, and you only see this (3 minute) delay when using this central? Can you show me a snippet of how you handle advertisements in your central device? If possible, could you do a sniffer trace of this happening, so we can see what causes this delay on the air. If you don't have a dedicated sniffer device, check out the nRF Sniffer that can be used with one of our DKs or the Dongle

Best regards,

Simon

[karanbakshi]

Hi Simon,

After changing scan window to similar to scan interval, delay issue in connection resolved. Now it is connected in couple of seconds. Earlier scan interval was 160 and window was 80 so I have made both equal to 160.

for my knowledge, if you know, Does this change in scan parameter affects in connection timing?

Regards,

Bipin