This example program shows how to set up a GAP advertising packet to broadcast data from the device out to anyone who may be listening.

Dependencies:   BLE_API mbed nRF51822

Fork of BLE_EvothingsExample_GAP by Austin Blackstone

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.

Video of use

Details

Fill in the data you want to transmit by changing the following line, try using the string representation by changing hte "CHangeThisData" field or send hex data by altering the hex data field.

// You have up to 26 bytes of advertising data to use.
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));

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);
...

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. In the Evothings Workbench you will find an example program called "mbed Evothings GAP", this Evothings Smartphone App is meant to be used with the above embedded mbed code. For instructions on how to use Evothings please see the reference section below.

Reference

Committer:
mbedAustin
Date:
Thu Apr 02 21:16:43 2015 +0000
Revision:
13:827dd2b32bb8
Parent:
12:06c984252bd1
Child:
14:1c15d473b42f
removed whitespace and ran code linter/cleanup

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedAustin 1:0692bee84264 1 // Headers necessary for mbed and BLE device mode
mbedAustin 0:5375be4301ed 2 #include "mbed.h"
mbedAustin 0:5375be4301ed 3 #include "BLEDevice.h"
mbedAustin 0:5375be4301ed 4
mbedAustin 1:0692bee84264 5 // BLE object
mbedAustin 1:0692bee84264 6 BLEDevice ble;
mbedAustin 0:5375be4301ed 7
mbedAustin 11:c9c0c4586c5f 8 // Optional: Device Name, add for human read-ability
mbedAustin 8:5442739198ec 9 //const static char DEVICE_NAME[] = "ChangeMe!!"; // Optional: device name
mbedAustin 5:fff16d283dcf 10
mbedAustin 11:c9c0c4586c5f 11 // You have up to 26 bytes of advertising data to use.
mbedAustin 13:827dd2b32bb8 12 const static uint8_t AdvData[] = {0x01,0x02,0x03,0x04,0x05}; // example of hex data
mbedAustin 8:5442739198ec 13 //const static uint8_t AdvData[] = {"ChangeThisData"}; // example of character data
mbedAustin 1:0692bee84264 14
mbedAustin 13:827dd2b32bb8 15 // Optional: Restart advertising when phone app disconnects
mbedAustin 13:827dd2b32bb8 16 void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
mbedAustin 13:827dd2b32bb8 17 {
mbedAustin 13:827dd2b32bb8 18 ble.startAdvertising();
mbedAustin 8:5442739198ec 19 }
mbedAustin 8:5442739198ec 20
mbedAustin 1:0692bee84264 21 // main program
mbedAustin 1:0692bee84264 22 int main(void)
mbedAustin 0:5375be4301ed 23 {
mbedAustin 1:0692bee84264 24 // Initialize BLE baselayer, always do this first!
mbedAustin 1:0692bee84264 25 ble.init();
mbedAustin 13:827dd2b32bb8 26
mbedAustin 11:c9c0c4586c5f 27 // Optional: add callback for disconnection
mbedAustin 13:827dd2b32bb8 28 // ble.onDisconnection(disconnectionCallback);
mbedAustin 1:0692bee84264 29
mbedAustin 1:0692bee84264 30 // Sacrifice 3B of 31B to Advertising Flags
mbedAustin 1:0692bee84264 31 ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE );
mbedAustin 4:d602b1c3aef4 32 ble.setAdvertisingType(GapAdvertisingParams::ADV_CONNECTABLE_UNDIRECTED);
mbedAustin 1:0692bee84264 33
mbedAustin 1:0692bee84264 34 // Sacrifice 2B of 31B to AdvType overhead, rest goes to AdvData array you define
mbedAustin 1:0692bee84264 35 ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, AdvData, sizeof(AdvData));
mbedAustin 13:827dd2b32bb8 36
mbedAustin 13:827dd2b32bb8 37 // Optional: Add name to device
mbedAustin 5:fff16d283dcf 38 //ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
mbedAustin 1:0692bee84264 39
mbedAustin 1:0692bee84264 40 // Set advertising interval. Longer interval = longer battery life
mbedAustin 12:06c984252bd1 41 ble.setAdvertisingInterval(100); // 100ms, set as percentage of a second
mbedAustin 1:0692bee84264 42 ble.startAdvertising();
mbedAustin 1:0692bee84264 43
mbedAustin 1:0692bee84264 44 // Infinite loop waiting for BLE events
mbedAustin 1:0692bee84264 45 for (;;) {
mbedAustin 8:5442739198ec 46 ble.waitForEvent(); // this saves battery while waiting for callback events
mbedAustin 1:0692bee84264 47 }
mbedAustin 1:0692bee84264 48 }