UCL IoT / Mbed 2 deprecated BLE_LED_Controller

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:
2014-12-18
Revision:
15:016434184568
Parent:
14:8ff3bfb6b19d

File content as of revision 15:016434184568:

/* 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 */

#define LED2CMD "led2"
#define CMD_LENGTH 4


//char rxPayload[CMD_SIZE];

BLEDevice  ble;                               // Create Bluetooth object
DigitalOut led1(LED1);                        // Set the pin attached to LED1 as an output
PwmOut led2(LED2);                        // Set the pin attached to LED2 as an output

UARTService *uartServicePtr;

/* BLE disconnected callback */
void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
{
    DEBUG("Disconnected!\n\r");
    DEBUG("Restarting the advertising process\n\r");
    ble.startAdvertising();
}
/* BLE UART data received callback */
void onDataWritten(const GattCharacteristicWriteCBParams *params)
{
    if ((uartServicePtr != NULL) && (params->charHandle == uartServicePtr->getTXCharacteristicHandle())) {     //If characters received over BLE
        uint16_t bytesRead = params->len;
        DEBUG("received %u bytes\n\r", bytesRead);
        DEBUG("Received string: '");
        DEBUG((const char *)params->data);             //Note the size of data expands to the largest string received. Need to use bytesRead to resize.
        DEBUG("'\n\r");
        if (!strncmp(LED2CMD,(const char *)params->data,CMD_LENGTH-1)){
            float value;
            char cmd[CMD_LENGTH];
            sscanf((const char *)params->data, "%s %f", cmd, &value );
            led2 = value;
            DEBUG("Cmd: %s LED Level = %f\n\r", cmd, value);
            }
        ble.updateCharacteristicValue(uartServicePtr->getRXCharacteristicHandle(), params->data,bytesRead);   // Echo received characters back over BLE
    }
}

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

int main(void)
{
    led1 = 1;
    led2 = 0.5;
    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);                                            // Define callback function for BLE disconnection event
    ble.onDataWritten(onDataWritten);                                                      // Define callback function for BLE Data received event

    /* setup advertising */
    ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED);             // Indicate that Legacy Bluetooth in 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));          // Set advertising interval to 1 second
    ble.startAdvertising();                                                               // Start advertising

    UARTService uartService(ble);                                                         // Create BLE UART service
    uartServicePtr = &uartService;                                                        // Initalise pointer to point to UART Service

    while (true) {
        ble.waitForEvent();                                                               // Wait for BLE events
    }
}