#define APP_ADV_INTERVAL                        MSEC_TO_UNITS(250, UNIT_0_625_MS)  
#define APP_ADV_TIMEOUT_IN_SECONDS              60                                

#define CENTRAL_MIN_CONN_INTERVAL              MSEC_TO_UNITS(50, UNIT_1_25_MS)  
#define CENTRAL_MAX_CONN_INTERVAL              MSEC_TO_UNITS(100, UNIT_1_25_MS)  
#define CENTRAL_SLAVE_LATENCY                  0                                 
#define CENTRAL_CONN_SUP_TIMEOUT               MSEC_TO_UNITS(4000, UNIT_10_MS)   

#define PERIPHERAL_MIN_CONN_INTERVAL           MSEC_TO_UNITS(50, UNIT_1_25_MS)   
#define PERIPHERAL_MAX_CONN_INTERVAL           MSEC_TO_UNITS(100, UNIT_1_25_MS)   
#define PERIPHERAL_SLAVE_LATENCY               0                                                   
#define PERIPHERAL_CONN_SUP_TIMEOUT            MSEC_TO_UNITS(1000, UNIT_10_MS)
               
#define SCAN_INTERVAL                           MSEC_TO_UNITS(100, UNIT_0_625_MS) 
#define SCAN_WINDOW                             MSEC_TO_UNITS(80, UNIT_0_625_MS)  
#define SCAN_TIMEOUT                            0x000A


void scan_start(void)
{
uint32_t              err_code;
// No devices in whitelist, hence non selective performed.
m_scan_param.active       = 0;            // Active scanning set.
m_scan_param.selective    = 0;            // Selective scanning not set.
m_scan_param.interval     = SCAN_INTERVAL;// Scan interval.
m_scan_param.window       = SCAN_WINDOW;  // Scan window.
m_scan_param.p_whitelist  = NULL;         // No whitelist provided.
m_scan_param.timeout      = SCAN_TIMEOUT;       // Scan timeout.
LOG_INFO("S0");
err_code = sd_ble_gap_scan_start(&m_scan_param);
LOG_INFO("error_code: %x\r\n",err_code);

APP_ERROR_CHECK(err_code);

}