File content as of revision 2:f8dfdded83bf:

#include "mbed.h"
#include "ble/BLE.h"

#define LED_RED     p22
#define LED_GREEN   p21
#define LED_BLUE    p23
#define BUTTON_PIN  p17
#define BATTERY_PIN p1

DigitalOut led1(p21);
const static char DEVICE_NAME[] = "Joe-Aidan";

struct Packet {
    uint32_t increasing_sequence;
};

static volatile bool  triggerSensorPolling = false;
void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *params)
{
    BLE::Instance(BLE::DEFAULT_INSTANCE).gap().startAdvertising(); // restart advertising
}
void periodicCallback(void)
{
    led1 = !led1; /* Do blinky on LED1 while we're waiting for BLE events */
    /* Note that the periodicCallback() executes in interrupt context, so it is safer to do
     * heavy-weight sensor polling from the main thread. */
    triggerSensorPolling = true;
}
void bleInitComplete(BLE::InitializationCompleteCallbackContext *params)
{
    BLE &ble          = params->ble;
    ble_error_t error = params->error;
    if (error != BLE_ERROR_NONE) {
        return;
    }
    ble.gap().onDisconnection(disconnectionCallback);
    /* Setup primary service. */
    // hrService = new HeartRateService(ble, hrmCounter, HeartRateService::LOCATION_FINGER);
    /* Setup auxiliary service. */
    // deviceInfo = new DeviceInformationService(ble, "ARM", "Model1", "SN1", "hw-rev1", "fw-rev1", "soft-rev1");
    /* Setup advertising. */
    // ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE);
    // ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list));
    // ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::GENERIC_HEART_RATE_SENSOR);
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
    ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
    ble.gap().setAdvertisingInterval(1000); /* 1000ms */
    ble.gap().startAdvertising();
}
int main(void)
{
    led1 = 1;
    Ticker ticker;
    ticker.attach(periodicCallback, 1); // blink LED every second
    BLE& ble = BLE::Instance(BLE::DEFAULT_INSTANCE);
    ble.init(bleInitComplete);
    
    /* SpinWait for initialization to complete. This is necessary because the
     * BLE object is used in the main loop below. */
    while (ble.hasInitialized()  == false) { /* spin loop */ }
    
    while (1) {
        // check for trigger from periodicCallback()
        if (triggerSensorPolling && ble.getGapState().connected) {
            triggerSensorPolling = false;
        } else {
            ble.waitForEvent(); // low power wait for event
        }
    }
}