How to turn a WaveShare nRF51-BLE400 into a discoverable beacon using mbed

Dependencies:   mbed BLE_API nRF51822

Port for WaveShare BLE400 (chip nRF51 Aliexpress devboard)
Android Evothings good example for Nordic nRF51822-DK

As target for mbed-online used <Nordic nRF51822>
- (Large green board Nordic nRF51822-mKIT, actually deprecated on 01/03/2019)

Briefly: Handle via Evothings BLE Application 4 LEDs and 2 Buttons(via notify messages).

Figure 1: Evothings Android application screenshot

Evothings application screenshot

Android Evothings application sources

Android application APK

Happy coding!
maxxir 02/03/19

Revision:
8:5442739198ec
Parent:
7:f9a2fa5b1d43
Child:
11:c9c0c4586c5f
--- a/main.cpp	Tue Mar 10 22:42:14 2015 +0000
+++ b/main.cpp	Tue Mar 17 19:45:19 2015 +0000
@@ -6,21 +6,28 @@
 // BLE object
 BLEDevice ble;
 
-//const static char     DEVICE_NAME[]        = "ChangeMe!!"; // change this
+// Optional 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.
+  * 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[] = {"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 
+void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason){
+    ble.startAdvertising(); 
+}
+
 // main program
 int main(void)
 {
     // Initialize BLE baselayer, always do this first!
     ble.init();
+    // ble.onDisconnection(disconnectionCallback); // Optional: add callback for disconnection
 
     // Sacrifice 3B of 31B to Advertising Flags
     ble.accumulateAdvertisingPayload(GapAdvertisingData::BREDR_NOT_SUPPORTED | GapAdvertisingData::LE_GENERAL_DISCOVERABLE );
@@ -29,7 +36,7 @@
     // Sacrifice 2B of 31B to AdvType overhead, rest goes to AdvData array you define
     ble.accumulateAdvertisingPayload(GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA, AdvData, sizeof(AdvData));
     
-    // Add name to device 
+    // Optional: Add name to device 
     //ble.accumulateAdvertisingPayload(GapAdvertisingData::COMPLETE_LOCAL_NAME, (uint8_t *)DEVICE_NAME, sizeof(DEVICE_NAME));
 
     // Set advertising interval. Longer interval = longer battery life
@@ -38,6 +45,6 @@
 
     // Infinite loop waiting for BLE events
     for (;;) {
-        ble.waitForEvent(); // this saves battery
+        ble.waitForEvent(); // this saves battery while waiting for callback events
     }
 }