File content as of revision 2:4b53d13d9851:

#include "mbed.h"
#include "ble/BLE.h"
#include "ble/DiscoveredCharacteristic.h"
#include "ble/DiscoveredService.h"
#include "ble_radio_notification.h"

BLE ble;
Serial pc(USBTX, USBRX);

DiscoveredCharacteristic accelChar;

const uint8_t MPU6050_service_uuid[] = {
    0x45,0x35,0x56,0x80,0x0F,0xD8,0x5F,0xB5,0x51,0x48,0x30,0x27,0x06,0x9B,0x3F,0xD9
};

const uint8_t MPU6050_Accel_Characteristic_uuid[] = {
    0x45,0x35,0x56,0x81,0x0F,0xD8,0x5F,0xB5,0x51,0x48,0x30,0x27,0x06,0x9B,0x3F,0xD9
};


UUID serviceUUID(MPU6050_service_uuid);
UUID accelUUID(MPU6050_Accel_Characteristic_uuid);


void scanCallback(const Gap::AdvertisementCallbackParams_t *params) {
    pc.printf("adv peerAddr[%02x %02x %02x %02x %02x %02x] rssi %d, isScanResponse %u, AdvertisementType %u\r\n",
           params->peerAddr[5], params->peerAddr[4], params->peerAddr[3], params->peerAddr[2], params->peerAddr[1], params->peerAddr[0],
           params->rssi, params->isScanResponse, params->type);
    
    
    ble.connect(params->peerAddr, Gap::ADDR_TYPE_RANDOM_STATIC, NULL, NULL);
}

void serviceDiscoveryCallback(const DiscoveredService *service) {
    pc.printf("service found...\r\n");    
}

void characteristicDiscoveryCallback(const DiscoveredCharacteristic *characteristicP) {
    pc.printf("characteristicDiscoveryCallback\r\n");
    
    const uint8_t *longUUIDBytes = characteristicP->getUUID().getBaseUUID();
    bool flag = true;

    if (characteristicP->getUUID().shortOrLong() != UUID::UUID_TYPE_SHORT) {
        for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++){
            if( longUUIDBytes[i]!=MPU6050_Accel_Characteristic_uuid[i]){
                flag=false;
            }
        }
        if(flag == true) {
            accelChar = *characteristicP;
            ble.gattClient().read(characteristicP->getConnHandle(), characteristicP->getValueHandle(), 0);
        }
    }

}

void connectionCallback(const Gap::ConnectionCallbackParams_t *params) {
    pc.printf("GAP_EVT_CONNECTED");
    
    if (params->role == Gap::CENTRAL) {
        ble.gattClient().launchServiceDiscovery(params->handle, serviceDiscoveryCallback, characteristicDiscoveryCallback, serviceUUID, accelUUID);
        //ble.stopScan();
    }
}

void discoveryTerminationCallback(Gap::Handle_t connectionHandle) {
    pc.printf("terminated SD for handle %u\r\n", connectionHandle);
}

void triggerRead(const GattReadCallbackParams *response) {
    printf("triggerRead.....");
    for(int i=0; i < response->len; i++){
        pc.printf("data %x", response->data[i]);  
    }
    pc.printf("\r\n");
    accelChar.read();
}

void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params){//(Gap::Handle_t handle, Gap::DisconnectionReason_t reason) {
    pc.printf("disconnected\r\n");
    wait(8.0);
    ble.gap().startScan(scanCallback);
}

void your_radio_callback_handler(bool radio_active)
{

}

int main(void) {
    pc.baud(9600);
    wait(8.0);
    pc.printf("start\r\n");

    ble.init();
    ble_radio_notification_init(NRF_APP_PRIORITY_HIGH,
                                NRF_RADIO_NOTIFICATION_DISTANCE_4560US,
                                your_radio_callback_handler);
    ble.onConnection(connectionCallback);
    ble.onDisconnection(disconnectionCallback);
    ble.gattClient().onServiceDiscoveryTermination(discoveryTerminationCallback);
    ble.gattClient().onDataRead(triggerRead);
    //ble.gattClient().onDataWrite(triggerToggledWrite);

    ble.gap().setScanParams(500, 400);
    ble.gap().startScan(scanCallback);

    while (true) {
    }
}