Bluetooth Low Energy
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
Revision 1:0692bee84264, committed 2015-02-13
- Comitter:
- mbedAustin
- Date:
- Fri Feb 13 20:59:53 2015 +0000
- Parent:
- 0:5375be4301ed
- Child:
- 2:7d230e007eee
- Commit message:
- Initial Commit of Evothings custom GAP example App
Changed in this revision
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/CustomAdvertisingPacket.h Fri Feb 13 20:59:53 2015 +0000
@@ -0,0 +1,59 @@
+
+#ifndef __BLE_EVOTHINGS_CUSTOM_GAP_H__
+#define __BLE_EVOTHINGS_CUSTOM_GAP_H__
+
+#include "BLEDevice.h" // must include this
+
+/**
+* @class iBeaconService
+* @brief iBeacon Service. This service sets up a device to broadcast advertising packets to mimic an iBeacon<br>
+*/
+
+class iBeaconService
+{
+public:
+ iBeaconService(BLEDevice &_ble, uint8_t proxUUID[16],uint16_t majNum,uint16_t minNum,uint8_t txP=0xC8, uint16_t compID=0x004C):
+ ble(_ble)
+ {
+ data.ID = 0x02; // Optional ID field
+ data.len = 0x15; // Len of remaining stuff (16B UUID, 2B Maj, 2B Min, 1B TxP)
+ data.majorNumber = ((majNum<<8) | (majNum >>8));
+ data.minorNumber = ((minNum<<8) | (minNum >>8));
+ data.txPower = txP; // The user should calibrate this to ~1meter fromt he device
+ data.companyID = compID; // Note: all iBeacons use the Apple ID of 0x004C
+
+ // copy across proximity UUID
+ for(int x=0; x<sizeof(data.proximityUUID); x++) {
+ data.proximityUUID[x]=proxUUID[x];
+ }
+
+ // Set up iBeacon data
+ // Generate the 0x020106 part of the iBeacon Prefix
+ ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE );
+ // Generate the 0x1AFF part of the iBeacon Prefix
+ ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, data.raw, sizeof(data.raw));
+
+ // Set advertising type
+ ble.setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
+ }
+
+public:
+ union {
+ uint8_t raw[25];
+ struct {
+ uint16_t companyID;
+ uint8_t ID;
+ uint8_t len;
+ uint8_t proximityUUID[16];
+ uint16_t majorNumber;
+ uint16_t minorNumber;
+ uint8_t txPower;
+ };
+ } data;
+
+private:
+ BLEDevice &ble;
+
+};
+
+#endif //__BLE_EVOTHINGS_CUSTOM_GAP_H__
--- a/main.cpp Wed Jan 28 00:30:09 2015 +0000
+++ b/main.cpp Fri Feb 13 20:59:53 2015 +0000
@@ -1,10 +1,38 @@
+
+// Headers necessary for mbed and BLE device mode
#include "mbed.h"
#include "BLEDevice.h"
+// BLE object
+BLEDevice ble;
-int
-main(void)
+/**
+ 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)
{
- printf("This is an example program...");
- while(1){}
-}
\ No newline at end of file
+ // 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 );
+
+ // 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.setAdvertisingType(GapAdvertisingParams::ADV_NON_CONNECTABLE_UNDIRECTED);
+ ble.setAdvertisingInterval(160); // 100ms; in multiples of 0.625ms.
+ ble.startAdvertising();
+
+ // Infinite loop waiting for BLE events
+ for (;;) {
+ ble.waitForEvent(); // this saves battery
+ }
+}
--- a/mbed.bld Wed Jan 28 00:30:09 2015 +0000 +++ b/mbed.bld Fri Feb 13 20:59:53 2015 +0000 @@ -1,1 +1,1 @@ -http://mbed.org/users/mbed_official/code/mbed/builds/4fc01daae5a5 \ No newline at end of file +http://mbed.org/users/mbed_official/code/mbed/builds/e188a91d3eaa \ No newline at end of file
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/nRF51822.lib Fri Feb 13 20:59:53 2015 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/teams/Nordic-Semiconductor/code/nRF51822/#0e7a9efee6d7