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

Committer:
mbedAustin
Date:
Fri Feb 13 20:59:53 2015 +0000
Revision:
1:0692bee84264
Parent:
0:5375be4301ed
Child:
3:e9646631084f
Initial Commit of Evothings custom GAP example App

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedAustin 1:0692bee84264 1
mbedAustin 1:0692bee84264 2 // Headers necessary for mbed and BLE device mode
mbedAustin 0:5375be4301ed 3 #include "mbed.h"
mbedAustin 0:5375be4301ed 4 #include "BLEDevice.h"
mbedAustin 0:5375be4301ed 5
mbedAustin 1:0692bee84264 6 // BLE object
mbedAustin 1:0692bee84264 7 BLEDevice ble;
mbedAustin 0:5375be4301ed 8
mbedAustin 1:0692bee84264 9 /**
mbedAustin 1:0692bee84264 10 You have up to 26 bytes of advertising data to use.
mbedAustin 1:0692bee84264 11 Make up your own encoding for these 26bytes, send it across
mbedAustin 1:0692bee84264 12 and decode it using the evothings app.
mbedAustin 1:0692bee84264 13 */
mbedAustin 1:0692bee84264 14 const static uint8_t AdvData[] = {"ChangeThisData"}; // example of character data
mbedAustin 1:0692bee84264 15 //const static uint8_t AdvData[] = {0x01,0x02,0x03,0x04,0x05}; // example of hex data
mbedAustin 1:0692bee84264 16
mbedAustin 1:0692bee84264 17 // main program
mbedAustin 1:0692bee84264 18 int main(void)
mbedAustin 0:5375be4301ed 19 {
mbedAustin 1:0692bee84264 20 // Initialize BLE baselayer, always do this first!
mbedAustin 1:0692bee84264 21 ble.init();
mbedAustin 1:0692bee84264 22
mbedAustin 1:0692bee84264 23 // Sacrifice 3B of 31B to Advertising Flags
mbedAustin 1:0692bee84264 24 ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE );
mbedAustin 1:0692bee84264 25
mbedAustin 1:0692bee84264 26 // Sacrifice 2B of 31B to AdvType overhead, rest goes to AdvData array you define
mbedAustin 1:0692bee84264 27 ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, AdvData, sizeof(AdvData));
mbedAustin 1:0692bee84264 28
mbedAustin 1:0692bee84264 29 // Set advertising interval. Longer interval = longer battery life
mbedAustin 1:0692bee84264 30 ble.setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
mbedAustin 1:0692bee84264 31 ble.setAdvertisingInterval(160); // 100ms; in multiples of 0.625ms.
mbedAustin 1:0692bee84264 32 ble.startAdvertising();
mbedAustin 1:0692bee84264 33
mbedAustin 1:0692bee84264 34 // Infinite loop waiting for BLE events
mbedAustin 1:0692bee84264 35 for (;;) {
mbedAustin 1:0692bee84264 36 ble.waitForEvent(); // this saves battery
mbedAustin 1:0692bee84264 37 }
mbedAustin 1:0692bee84264 38 }