Central/ Peripheral example: Central Device connects to a Peripheral called "LED" and additionally a led can be toggled with a button -> BLE_LED_PERIPHERAL needed

Dependencies:   BLE_API mbed nRF51822

Fork of BLE_LED_CENTRAL by Alex Gernhaeuser

main.cpp

Committer:
Alexgerni
Date:
2017-08-08
Revision:
0:26b1912de8d8

File content as of revision 0:26b1912de8d8:

/* 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"

DigitalOut alivenessLED(p16, 0);
InterruptIn button(p9);
Serial pc(p5, p4);
Ticker ticker, ticker2;

static DiscoveredCharacteristic ledCharacteristic;
static const char PEER_NAME[] = "LED";

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

void buttonPressedCallback(void)
{
    /* Note that the buttonPressedCallback() executes in interrupt context, so it is safer to access
     * BLE device API from the main thread. */
    uint8_t toggledValue = 0x1;
    ledCharacteristic.write(1, &toggledValue);
    pc.printf("LED on... \n");
}

void buttonReleasedCallback(void)
{
    /* Note that the buttonPressedCallback() executes in interrupt context, so it is safer to access
     * BLE device API from the main thread. */
    uint8_t toggledValue = 0x0;
    ledCharacteristic.write(1, &toggledValue);
    pc.printf("LED off... \n");
}

void advertisementCallback(const Gap::AdvertisementCallbackParams_t *params) 
{
    // parse the advertising payload, looking for data type COMPLETE_LOCAL_NAME
    // The advertising payload is a collection of key/value records where
    // byte 0: length of the record excluding this byte
    // byte 1: The key, it is the type of the data
    // byte [2..N] The value. N is equal to byte0 - 1
    for (uint8_t i = 0; i < params->advertisingDataLen; ++i) {

        const uint8_t record_length = params->advertisingData[i];
        if (record_length == 0) {
            continue;
        }
        const uint8_t type = params->advertisingData[i + 1];
        const uint8_t* value = params->advertisingData + i + 2;
        const uint8_t value_length = record_length - 1;

        if(type == GapAdvertisingData::COMPLETE_LOCAL_NAME) {
            if ((value_length == sizeof(PEER_NAME)) && (memcmp(value, PEER_NAME, value_length) == 0)) {
                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::Instance().gap().connect(params->peerAddr, Gap::ADDR_TYPE_RANDOM_STATIC, NULL, NULL);
                break;
            }
        }
        i += record_length;
    }
}

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

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

void disconnectionCallback(const Gap::DisconnectionCallbackParams_t *) 
{
    pc.printf("disconnected\r\n");
    /* Start scanning and try to connect again */
    BLE::Instance().gap().startScan(advertisementCallback);
}

void onBleInitError(BLE &ble, ble_error_t error)
{
   /* Initialization error handling should go here */
}

void bleInitComplete(BLE::InitializationCompleteCallbackContext *params)
{
    BLE&        ble   = params->ble;
    ble_error_t error = params->error;

    if (error != BLE_ERROR_NONE) {
        /* In case of error, forward the error handling to onBleInitError */
        onBleInitError(ble, error);
        return;
    }

    /* Ensure that it is the default instance of BLE */
    if (ble.getInstanceID() != BLE::DEFAULT_INSTANCE) {
        return;
    }

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

    // scan interval: 400ms and scan window: 400ms.
    // Every 400ms the device will scan for 400ms
    // This means that the device will scan continuously.
    ble.gap().setScanParams(400, 400);
    ble.gap().startScan(advertisementCallback);
}


int main(void) {
    pc.baud(115200);
    pc.printf("Initialization starts... \n");
    
    ticker.attach(periodicCallback, 1); /* Blink LED every second */
    button.fall(buttonPressedCallback);
    button.rise(buttonReleasedCallback);

    BLE &ble = BLE::Instance();
    ble.init(bleInitComplete);
    
    while (true) {
        ble.waitForEvent();
    }
}