Demonstration code showing how to control an LED over Bluetooth Low Energy using the UARTService
Dependencies: BLE_API mbed nRF51822
Fork of BLE_LoopbackUART by
This programme demonstrates the use of the UARTService to send command strings over Bluetooth Low Energy (BLE) to control devices attached to the nRF51822 board.
In this example you can use a BLE connection from smart phone to turn on and off LED2 on the board.
Sending the character string "led2 on" will turn the LED on and "led2 off" will turn it off.
The command that is received is also echoed back via BLE to the sending device.
You can use the nRF UART App on and Android or iOS smart phone with BLE to test this out https://www.nordicsemi.com/eng/Products/nRFready-Demo-APPS
I have also ported the source code for the Android app into Android studio which should be a good starting point for developing your own custom App https://github.com/bennthomsen/nRF_UART. If you want to start using this within Android Studio create for own fork in GitHub and then from within Android Studio VCS>Checkout from Version Control>GitHub
main.cpp
- Committer:
- djmannion
- Date:
- 2015-01-02
- Revision:
- 15:2a9916011a2a
- Parent:
- 14:8ff3bfb6b19d
File content as of revision 15:2a9916011a2a:
/* 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 LED2OFF "led2 off" #define LED2ON "led2 on" //char rxPayload[CMD_SIZE]; BLEDevice ble; // Create Bluetooth object DigitalOut led1(LED1); // Set the pin attached to LED1 as an output DigitalOut 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(LED2ON,(const char *)params->data,bytesRead)) led2 = 1; // If the received and command string are equal turn led2 on. Note strcmp returns 0 if strings are equal if (!strncmp(LED2OFF,(const char *)params->data,bytesRead)) led2 = 0; // If the received and command string are equal turn led2 off. //Toggle LED2 when data received 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; 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| GapAdvertisingData::LE_GENERAL_DISCOVERABLE); // 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 } }