Example of BLE scan/connect/service discovery

Fork of BLE_LEDBlinker by Bluetooth Low Energy

main.cpp

Committer:
rgrover1
Date:
2015-06-29
Revision:
6:1730f66fb14d
Parent:
5:3bbad34d1a85
Child:
7:61e2224ec9a0

File content as of revision 6:1730f66fb14d:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2015 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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

BLE ble;

DigitalOut alivenessLED(LED1, 1);
bool triggerLedCharacteristic = false;
DiscoveredCharacteristic ledCharacteristic;

void periodicCallback(void) {
    alivenessLED = !alivenessLED; /* Do blinky on LED1 while we're waiting for BLE events */
}

void advertisementCallback(const Gap::AdvertisementCallbackParams_t *params) {
    if (params->peerAddr[0] != 0x29) { /* !ALERT! Alter this filter to suit your device. */
        return;
    }
    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.gap().connect(params->peerAddr, Gap::ADDR_TYPE_RANDOM_STATIC, NULL, NULL);
}

void serviceDiscoveryCallback(const DiscoveredService *service) {
    if (service->getUUID().shortOrLong() == UUID::UUID_TYPE_SHORT) {
        printf("S UUID-%x attrs[%u %u]\r\n", service->getUUID().getShortUUID(), service->getStartHandle(), service->getEndHandle());
    } else {
        printf("S UUID-");
        const uint8_t *longUUIDBytes = service->getUUID().getBaseUUID();
        for (unsigned i = 0; i < UUID::LENGTH_OF_LONG_UUID; i++) {
            printf("%02x", longUUIDBytes[i]);
        }
        printf(" attrs[%u %u]\r\n", service->getStartHandle(), service->getEndHandle());
    }
}

void characteristicDiscoveryCallback(const DiscoveredCharacteristic *characteristicP) {
    printf("  C UUID-%x valueAttr[%u] props[%x]\r\n", characteristicP->getShortUUID(), characteristicP->getValueHandle(), (uint8_t)characteristicP->getProperties().broadcast());
    if (characteristicP->getShortUUID() == 0xa001) { /* !ALERT! Alter this filter to suit your device. */
        ledCharacteristic        = *characteristicP;
        triggerLedCharacteristic = true;
    }
}

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

void connectionCallback(const Gap::ConnectionCallbackParams_t *params) {
    if (params->role == Gap::CENTRAL) {
        ble.gattClient().onServiceDiscoveryTermination(discoveryTerminationCallback);
        ble.gattClient().launchServiceDiscovery(params->handle, serviceDiscoveryCallback, characteristicDiscoveryCallback, 0xa000, 0xa001);
    }
}

void triggerToggledWrite(const GattReadCallbackParams *response) {
    if (response->handle == ledCharacteristic.getValueHandle()) {
#if DUMP_READ_DATA
        printf("triggerToggledWrite: handle %u, offset %u, len %u\r\n", response->handle, response->offset, response->len);
        for (unsigned index = 0; index < response->len; index++) {
            printf("%c[%02x]", response->data[index], response->data[index]);
        }
        printf("\r\n");
#endif

        uint8_t toggledValue = response->data[0] ^ 0x1;
        ledCharacteristic.write(1, &toggledValue);
    }
}

void triggerRead(const GattWriteCallbackParams *response) {
    if (response->handle == ledCharacteristic.getValueHandle()) {
        ledCharacteristic.read();
    }
}

void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason) {
    printf("disconnected\r\n");
}

int main(void) {
    Ticker ticker;
    ticker.attach(periodicCallback, 1);

    ble.init();
    ble.gap().onConnection(connectionCallback);
    ble.gap().onDisconnection(disconnectionCallback);

    /* Request for comments: should setupOnDataRead() be a static for DiscoveredCharacteristic?
     * Or should it be passed in as a parameter to read()? */
    DiscoveredCharacteristic::setupOnDataRead(triggerToggledWrite);
    DiscoveredCharacteristic::setupOnDataWrite(triggerRead);

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

    while (true) {
        if (triggerLedCharacteristic && !ble.gattClient().isServiceDiscoveryActive()) {
            triggerLedCharacteristic = false;
            ledCharacteristic.read(); /* We could have issued this read just as easily from
                                       * characteristicDiscoveryCallback(); but
                                       * invoking it here demonstrates the use
                                       * of isServiceDiscoveryActive() and also
                                       * the fact that it is permitted to
                                       * operate on application-local copies of
                                       * DiscoveredCharacteristic. */
        }
        ble.waitForEvent();
    }
}