Implement Immediate Alert Service

[kqkq]

Immediate Alert Service is a simple service which exposes a control point to allow a peer device to cause the device to immediately alert.

This pull request implements this service.

Here's the demo program. Write 0, 1 or 2 to the characteristic Alert Level could cause the LED to blink.

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

Ticker alertTimer;

DigitalOut led(LED1, 0);

static const char *DEVICE_NAME = "Alert";
static const uint16_t uuid16_list[] = {GattService::UUID_IMMEDIATE_ALERT_SERVICE};

ImmediateAlertService *alert;

void tickAlertHandler()
{
    led = !led;
}

void alertHandler(ImmediateAlertService::AlertLevel_t alertLevel)
{
    /* Blink a LED if an alert is received */
    if(alertLevel == ImmediateAlertService::NO_ALERT)
    {
        alertTimer.detach();
        led = 0;
    }
    if(alertLevel == ImmediateAlertService::MILD_ALERT)
    {
        alertTimer.attach(tickAlertHandler, 1.0);
    }
    if(alertLevel == ImmediateAlertService::HIGH_ALERT)
    {
        alertTimer.attach(tickAlertHandler, 0.25);
    }
}

void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *)
{
    BLE::Instance(BLE::DEFAULT_INSTANCE).gap().startAdvertising();
    /* Cancel the alert on disconnecting */
    led = 0;
    alert->setAlertLevel(ImmediateAlertService::NO_ALERT);
    alertHandler(ImmediateAlertService::NO_ALERT);
}

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 advertising */
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE); // BLE only, no classic BT
    ble.gap().setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED); // advertising type
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME)); // add name
    ble.gap().accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list)); // UUID's broadcast in advertising packet
    ble.gap().setAdvertisingInterval(100); // 100ms.

    /* Add service */
    alert  = new ImmediateAlertService(ble, alertHandler);

    /* Start advertising */
    ble.gap().startAdvertising();
}

int main(void)
{
    BLE& ble = BLE::Instance(BLE::DEFAULT_INSTANCE);
    ble.init(bleInitComplete);

    while (!ble.hasInitialized()) { /* spin loop */ }

    while (true) {
        ble.waitForEvent(); // allows or low power operation
    }
}

[ciarmcom]

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[pan-]

Hello,

The message Automatic CI verification build not done, please verify manually. means that our continuous integration system didn't try to verify your pull request, I will look at it in the course of the day.

[crespum]

@kqkq I haven't seen this PR until now. I've submitted a similar one with the difference that I put some documentation in the methods and I included support for class methods to be callback functions. You can check it in #180 but I think we should merge just one of them.