File content as of revision 2:89f008ca5911:

#include "mbed.h"
#include "ble/BLE.h"
#include "ble/services/UARTService.h"
#include "Serial.h"
#include "ADXL345.h"
#include "mbed.h"

#define NEED_CONSOLE_OUTPUT 1 /* Set this if you need debug messages on the console;
                               * it will have an impact on code-size and power consumption. */

#if NEED_CONSOLE_OUTPUT
#define DEBUG(...) { printf(__VA_ARGS__); }
#else
#define DEBUG(...) /* nothing */
#endif /* #if NEED_CONSOLE_OUTPUT */

ADXL345 accelerometer(p5, p6, p7, p8); // (SDA, SDO, SCL, CS);
BLEDevice  ble;
DigitalOut led1(LED1);
Serial uart1(USBTX,USBRX);
UARTService *uartServicePtr;


void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
{
    DEBUG("Disconnected!\n\r");
    DEBUG("Restarting the advertising process\n\r");
    ble.startAdvertising();
}

void connectionCallback(const Gap::ConnectionCallbackParams_t *params) {
   
    DEBUG("Connected!\n\r");
    
}


uint8_t b[40]={'a','d','q','w'};
void onDataWritten1(const GattWriteCallbackParams *params)
{
    
    
    if ((uartServicePtr != NULL) && (params->handle == uartServicePtr->getTXCharacteristicHandle())) {
        uint16_t bytesRead = params->len;
        DEBUG("received %u bytes %s\n\r", bytesRead,params->data);
       // if(sFlag == 1)
       //     ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), (const uint8_t*)b/*params->data*/, 4/*bytesRead*/);
    }
}


void periodicCallback(void)
{
    led1 = !led1;
    
}


int main() 
{
    uart1.baud(9600);
    int readings[3] = {0, 0, 0};
    uart1.printf("Starting ADXL345 test...\n");
    uart1.printf("Device ID is: 0x%02x\n", accelerometer.getDevId());

    //Go into standby mode to configure the device.
    accelerometer.setPowerControl(0x00);

    //Full resolution, +/-16g, 4mg/LSB.
    accelerometer.setDataFormatControl(0x0B);
    
    //3.2kHz data rate.
    accelerometer.setDataRate(ADXL345_3200HZ);

    //Measurement mode.
    accelerometer.setPowerControl(0x08);
    
    char buffer [20];
       
    // Test Daata
    memset(&buffer, 0, sizeof(buffer));
    int16_t reading_1 = 54;
    int16_t reading_2 = 42;
    int16_t reading_3 = 32;
       
    snprintf(buffer,20,"data: %d, %d, %d\n", reading_1, reading_2, reading_3);
    
    led1 = 1;
    uart1.baud(9600);
    Ticker ticker;
    ticker.attach(periodicCallback, 1);
    
    DEBUG("Initialising the nRF51822\n\r");
    ble.init();
    ble.onDisconnection(disconnectionCallback);
    ble.onConnection(connectionCallback);
    ble.onDataWritten(onDataWritten1);

    /* setup advertising */
    ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED);
    ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
    ble.accumulateAdvertisingPayload(GapAdvertisingData::SHORTENED_LOCAL_NAME,
                                     (const uint8_t *)"BLE UART", sizeof("BLE UART") - 1);
    ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_128BIT_SERVICE_IDS,
                                     (const uint8_t *)UARTServiceUUID_reversed, sizeof(UARTServiceUUID_reversed));

    ble.setAdvertisingInterval(1000); /* 1000ms; in multiples of 0.625ms. */
    ble.startAdvertising();

    UARTService uartService(ble);
    uartServicePtr = &uartService;

    while (1) {
        ble.waitForEvent();
        wait(0.1);
        accelerometer.getOutput(readings);
        
        //13-bit, sign extended values.
        uart1.printf("%i, %i, %i\n", (int16_t)readings[0], (int16_t)readings[1], (int16_t)readings[2]);
        
        memset(&buffer, 0, sizeof(buffer));
        snprintf(buffer, 20, "data: %d, %d, %d\n", (int16_t)readings[0],(int16_t)readings[1], (int16_t)readings[2]);
        ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), (uint8_t*)buffer, sizeof(buffer), false);

    }

}