BLE Connection Issue with nRF52840 Chipset to iOS App

[Himansu]

Hi Nordic Team,

Some time facing Connection issue in Mobile app and some time device advertisement is not getting in app.

I am using below chipset and configuration.

SDK: 15.3.2
Softdevice: S340/6.1.1
Chipset: nRF52840

My Peripheral Side Connection Interval.
#define MIN_CONN_INTERVAL 8 /**< Minimum acceptable connection interval (10 mili seconds), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL 80 /**< Maximum acceptable connection interval (100 mili second), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY 4 /**< Slave latency. */
#define CONN_SUP_TIMEOUT 320 /**< Connection supervisory timeout (3.2 seconds), Supervision Timeout uses 10 ms units. */

Advertisement Interval: 250 ms
Advertisement Type: Continue

I am getting below error in iOS App when device is not able to connect with App.
Disconnect Peripheral :, The connection has timed out unexpectedly.
Disconnect Peripheral :, The specified device has disconnected from us.

Why getting this error ?
Any issue in above parameter as per Apple BLE Connection Interval Parameter guideline ?

Regards,
Himansu

[Himansu]

Hi ,

Please also note, we are use BLE + ANT both parallel.

This is not generated all time but facing most of time when ANT channel in searching Mode.

I am also added ANT radio channel Priority is low using below function.

err_code = sd_ant_coex_config_get(ANT_SCAN_CHANNEL_NUMBER, &ant_coex_config, NULL);
APP_ERROR_CHECK(err_code);
ant_coex_config.pucBuffer[0] = 0; //disable all configuration
err_code = sd_ant_coex_config_set(ANT_SCAN_CHANNEL_NUMBER, &ant_coex_config, NULL);
APP_ERROR_CHECK(err_code);

Let me know, how overcome BLE Connection issue.

Regards,

Himansu Donga

[Vidar Berg]

Hello Himansu,

I would suggest to try disabling ANT temporarily to see if it makes the iPhone connection stable. Also, the connection parameters you listed above does not follow the Apple recommendations, so I would consider changing those. The connection parameter recommendations are given in section 35.6 of their design guidelines document here https://developer.apple.com/accessories/Accessory-Design-Guidelines.pdf

Regards,

Vidar