Austin Blackstone / Mbed 2 deprecated BLE_EvothingsExample_GAP

mbed application to pair with Evothings App, demonstrates how to create a custom GAP advertising packet.

Dependencies:   BLE_API mbed nRF51822

Intro

This code is meant to demonstrate how to use the GAP advertising layer to transmit data. Keep in mind you only have 26B of data in the Manufacturer data field to use.

Details

Fill in the data you want to transmit by changing the following line

/**
  You have up to 26 bytes of advertising data to use.
  Make up your own encoding for these 26bytes, send it across
  and decode it using the evothings app.
 */
const static uint8_t AdvData[] = {"ChangeThisData"};             // example of character data
//const static uint8_t AdvData[] = {0x01,0x02,0x03,0x04,0x05};   // example of hex data

Name Device

Optionally you can give your device a name by uncommenting the following two lines

//const static char     DEVICE_NAME[]        = "ChangeMe!!"; // change this
...
//ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));

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.

Add Disconnection Callback

This code is bare bones and as such does not restart advertising when disconnected from a device. To add this functionality into your code please add the following callback

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

and the following initialization to your main function

int 
main(void)
{
...
ble.onDisconnection(disconnectionCallback);
...

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:
2015-03-10
Revision:
4:d602b1c3aef4
Parent:
3:e9646631084f
Child:
5:fff16d283dcf

File content as of revision 4:d602b1c3aef4:


// Headers necessary for mbed and BLE device mode
#include "mbed.h"
#include "BLEDevice.h"

// BLE object
BLEDevice ble;

/**
  You have up to 26 bytes of advertising data to use.
  Make up your own encoding for these 26bytes, send it across
  and decode it using the evothings app.
 */
//const static uint8_t AdvData[] = {"ChangeThisData"};             // example of character data
const static uint8_t AdvData[] = {0x01,0x02,0x03,0x04,0x05};   // example of hex data

// main program
int main(void)
{
    // Initialize BLE baselayer, always do this first!
    ble.init();

    // Sacrifice 3B of 31B to Advertising Flags
    ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE );
    ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);

    // Sacrifice 2B of 31B to AdvType overhead, rest goes to AdvData array you define
    ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, AdvData, sizeof(AdvData));

    // Set advertising interval. Longer interval = longer battery life
    ble.setAdvertisingInterval(160); // 100ms; in multiples of 0.625ms.
    ble.startAdvertising();

    // Infinite loop waiting for BLE events
    for (;;) {
        ble.waitForEvent(); // this saves battery
    }
}