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
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
Diff: main.cpp
- Revision:
- 11:c9c0c4586c5f
- Parent:
- 8:5442739198ec
- Child:
- 12:06c984252bd1
--- a/main.cpp Wed Mar 18 21:02:22 2015 +0000 +++ b/main.cpp Thu Apr 02 17:19:16 2015 +0000 @@ -6,18 +6,15 @@ // BLE object BLEDevice ble; -// Optional name, add for human read-ability +// Optional: Device Name, add for human read-ability //const static char DEVICE_NAME[] = "ChangeMe!!"; // Optional: device name -/** - * 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. - */ +// 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 -// Restart advertising when phone app disconnects +// Optional: Restart advertising when phone app disconnects void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason){ ble.startAdvertising(); } @@ -27,7 +24,9 @@ { // Initialize BLE baselayer, always do this first! ble.init(); - // ble.onDisconnection(disconnectionCallback); // Optional: add callback for disconnection + + // Optional: add callback for disconnection + // ble.onDisconnection(disconnectionCallback); // Sacrifice 3B of 31B to Advertising Flags ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE ); @@ -40,7 +39,7 @@ //ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME)); // Set advertising interval. Longer interval = longer battery life - ble.setAdvertisingInterval(160); // 100ms; in multiples of 0.625ms. + ble.setAdvertisingInterval(0.1); // 100ms, set as percentage of a second ble.startAdvertising(); // Infinite loop waiting for BLE events