Connection interval for multiple connections

[hrms]

I connect one central and two peripherals

Both peripherals set the connection interval to 100

Observing PA / LNA shows that one is communicating in 100ms

But the other is at 200ms intervals

Are there any restrictions?

I tried to send every 100ms, but couldn't
Connection event does not occur every 100ms

Peripheral cannot send packets at connection intervals because it does not return packets at connection intervals

There was no problem with one
This problem occurs when there are multiple connections

[bjorn-spockeli]

Hi hrms, 

Im not quite sure if I understand your setup. Do you have two peripheral devices based on a nRF52xxx SoC that have an external PA/LNA and you measure the time between when the PA is enabled for each of them?

What have you set as the preferred connection parameters in the code, i.e.

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(10, UNIT_1_25_MS)             /**< Minimum acceptable connection interval (10 ms). */
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(100, UNIT_1_25_MS)            /**< Maximum acceptable connection interval (100 ms) */

Also it would be useful if you could capture a on-air trace using the nRF Sniffer plugin in Wireshark and a NRF52 DK, see https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE. Then we would be able to see the connection parameter negotiation for both the links. 

Best regards

Bjørn

[hrms]

Connection interval is set to 100ms for both MAX and MIN

All equipment used is nRF52840Develop Kit

[bjorn-spockeli]

Ok, so you have configured the SoftDevice to control GPIos for an external PA/LNA using sd_ble_opt_set(BLE_COMMON_OPT_PA_LNA, &opt)?

An on-air trace is the easiest way to verify the connection interval. 

Best regards

Bjørn