Application for nRF51822 mbed KIT that controls the intensity of LED2 using the BLE UART Service. Works with the Android App BLE_mbed_Remote available here https://github.com/bennthomsen/BLE_mbed_Remote

Dependencies:   BLE_API mbed nRF51822

Fork of BLE_UART_LEDControl_Echo by UCL IoT

This program demonstrates the use of the BLE UART Service to receive and send commands in order to remotely control the operation. In this example the intensity of LED2 can be remotely controlled.

The program accepts commands of the form "led2 0.1" over the BLE UART Service and uses these to set the duty cycle of the PWM Output that is connected to LED2 on the nRF51822 mbed KIT.

An Example Android App is available here https://github.com/bennthomsen/BLE_mbed_Remote. The complete source code and Android Studio Project files are available and can simply be pulled into Android Studio. The App implements sending of text, LED on off Button and a slider to control the LED brightness. At this stage setting the switch to off sets the PWM duty cycle to 0.0, however due to the PWMOut implementation in mbed the LED is not completely off at this point.

main.cpp

Committer:
bthomsen
Date:
2014-12-17
Revision:
12:36a9f01cfa0a
Parent:
10:633cec718bf4
Child:
13:291a8f177400

File content as of revision 12:36a9f01cfa0a:

/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 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 "BLEDevice.h"

#include "UARTService.h"

#define NEED_CONSOLE_OUTPUT 0 /* 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 */

BLEDevice  ble;
DigitalOut led1(LED1);

UARTService *uartServicePtr;

void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
{
    DEBUG("Disconnected!\n\r");
    DEBUG("Restarting the advertising process\n\r");
    ble.startAdvertising();
}

void onDataWritten(const GattCharacteristicWriteCBParams *params)
{
    if ((uartServicePtr != NULL) && (params->charHandle == uartServicePtr->getTXCharacteristicHandle())) {
        uint16_t bytesRead = params->len;
        DEBUG("received %u bytes\n\r", bytesRead);
        ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), params->data, bytesRead);
    }
}

/* Periodic Ticker callback */
void periodicCallback(void)
{
    led1 = !led1;                             // Toggle LED 1
}

int main(void)
{
    led1 = 1;
    Ticker ticker;                            // Create period timer
    ticker.attach(periodicCallback, 1);       // Attach ticker callback function with a period of 1 second

    DEBUG("Initialising the nRF51822\n\r");
    ble.init();
    ble.onDisconnection(disconnectionCallback);
    ble.onDataWritten(onDataWritten);

    /* 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(Gap::MSEC_TO_ADVERTISEMENT_DURATION_UNITS(1000));
    ble.startAdvertising();

    UARTService uartService(ble);
    uartServicePtr = &uartService;

    while (true) {
        ble.waitForEvent();
    }
}