Hi, I tired Nordic Uart Service example on Nexus 5 Android ver 5.1.1, but I am not able to connect. I am able to connect to Samsung S6 and Nexus Android ver 4.4.4. I am using SDK 10.0 and S130 on nRF51822xxaa. My minimum connection interval is 1 second. I have same problem in all Android 6.0.1 version smart devices. Following is my configuration:
#define APP_ADV_INTERVAL 1600//1600*0.625 = 1 second /**< The advertising interval (in units of 0.625 ms. This value corresponds to 40 ms). */
#define APP_ADV_TIMEOUT_IN_SECONDS 180 /**< The advertising timeout (in units of seconds). */
#define APP_TIMER_PRESCALER 0 /**< Value of the RTC1 PRESCALER register. */
#define MIN_CONN_INTERVAL MSEC_TO_UNITS(20, UNIT_1_25_MS) /**< Minimum acceptable connection interval (20 ms), Connection interval uses 1.25 ms units. */
#define MAX_CONN_INTERVAL MSEC_TO_UNITS(75, UNIT_1_25_MS) /**< Maximum acceptable connection interval (75 ms), Connection interval uses 1.25 ms units. */
#define SLAVE_LATENCY 0 /**< Slave latency. */
#define CONN_SUP_TIMEOUT MSEC_TO_UNITS(4000, UNIT_10_MS) /**< Connection supervisory timeout (4 seconds), Supervision Timeout uses 10 ms units. */
#define FIRST_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(5000, APP_TIMER_PRESCALER) /**< Time from initiating event (connect or start of notification) to first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY APP_TIMER_TICKS(30000, APP_TIMER_PRESCALER) /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT 3
