Austin Blackstone / Mbed 2 deprecated BLE_EvothingsExample_GATT

This is an mbed side application meant to demonstrate how to create a custom GATT service/characteristic with Evothings.

Dependencies:   BLE_API mbed nRF51822

Intro

This code is meant to be run on an mbed enabled BLE board and paired with the mbed-evothings-customGATT smartphone application.

Details

This code is a demonstration of how to create a custom service (UUID=0xA0000) with two characteristics, a read only characteristic (UUID=0xA001) and a write characteristic (UUID=0xA002). What is written to the write characteristic will be copied across to the read characteristic and broadcast out. If a single byte is written it will be used to toggle the on board LED, if more than 1 byte is written the data will be written out to the terminal. The default max size is 10bytes.

Viewing Data

You can use either the LightBlue app on iOS or the nRF Master Control Panel application on Android to view the advertising data. Alternatively you can use a custom Evothings App to view the data.

Evothings?

Evothings is a rapid prototyping environment that uses cordova to enable you to rapidly develop smartphone applications in Javascript. Please download the Evothings workbench to your computer and the Evothings client to your smartphone. Then grab the code from the github page, drag and drop the index.htm file into Evothings workbench and run it on the Evothings client.

Reference

main.cpp

Committer:
mbedAustin
Date:
2015-03-09
Revision:
7:f6814152873c
Parent:
6:97b22b5bfbb8
Child:
8:60ede963dfe2

File content as of revision 7:f6814152873c:

#include "mbed.h"
#include "BLEDevice.h"
#include "CustomService.h"


// BLE object
BLEDevice ble;

// LED object
DigitalOut led(LED1);

const static char     DEVICE_NAME[]        = "ChangeMe!!"; // change this
static const uint16_t uuid16_list[]        = {0xFFFF}; //Custom UUID, FF is reserved for development

// Set Up Characteristics
static uint8_t readValue[1] = {0x00};
GattCharacteristic readChar(0xAAAA /* read char UUID*/, readValue, sizeof(readValue), sizeof(readValue),
                        GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_READ | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);

static uint8_t writeValue[1] = {0x00};
GattCharacteristic writeChar(0xBBBB /*write char UUID*/, writeValue, sizeof(writeValue), sizeof(writeValue),
                            GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_WRITE | GattCharacteristic::BLE_GATT_CHAR_PROPERTIES_NOTIFY);

GattCharacteristic *characteristics[] = {&readChar, &writeChar};

// Set up custom service
GattService        customService(0x221D /*Service UUID*/, characteristics, sizeof(characteristics) / sizeof(GattCharacteristic *));


// Restart advertising when phone app disconnects
void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
{
    ble.startAdvertising(); // restart advertising
}

// handle writes to writeCharacteristic
void writeCharCallback(const GattCharacteristicWriteCBParams *params)
{
    led = params->data[0];
    printf("LED Written To, value=%x",params->data[0]);
    // TODO: update the readChar value to match write char, or better yet give it an english value
    // TODO: update with info from here : http://developer.mbed.org/forum/team-63-Bluetooth-Low-Energy-community/topic/5502/
}

int
main(void)
{
    led = 1;    // turn LED off
    ble.init();
    ble.onDisconnection(disconnectionCallback);
    ble.onDataWritten(writeCharCallback); //TODO: this is not correct, figure out correct syntax

    /* setup advertising */
    ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE); // BLE only, no classic BT
    ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED); // advertising type
    ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME)); // add name
    ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LIST_16BIT_SERVICE_IDS, (uint8_t *)uuid16_list, sizeof(uuid16_list)); // UUID's broadcast in advertising packet
    ble.setAdvertisingInterval(160); /* 100ms; in multiples of 0.625ms. */
    

    ble.addService(customService); // Add our custom service to device

    ble.startAdvertising(); // start advertising
    while (true) {
        ble.waitForEvent(); //Save power
    }
    
    
    // TODO: impliment the rest of triggering for LED based on Write of characteristic.
    // TODO: impliment a read characteristic that sends text back to app
    // take a look at http://developer.mbed.org/teams/Bluetooth-Low-Energy/code/BLE_GroveColourSensor/file/000c8f8c7f03/main.cpp for inspiration.
}