feat: ✨ tune service advertisement so apps like OpenTracks can find the hrm service

apps/bootgatthrm/boot.js

@@ -4,14 +4,30 @@
      * This function prepares BLE heart rate Advertisement.
      */
 
+    NRF.setAdvertising(
+      {
+        0x180d: undefined
+      },
+      {
+        // We need custom Advertisement settings for Apps like OpenTracks
+        connectable: true,
+        discoverable: true,
+        scannable: true,
+        whenConnected: true,
+      }
+    );
+
     NRF.setServices({
       0x180D: { // heart_rate
         0x2A37: { // heart_rate_measurement
           notify: true,
           value: [0x06, 0],
+        },
+        0x2A38: { // Sensor Location: Wrist
+          value: 0x02,
         }
       }
-    }, { advertise: [0x180d] });
+    });
 
   }
   function updateBLEHeartRate(hrm) {
@@ -23,11 +39,11 @@
       NRF.updateServices({
         0x180D: {
           0x2A37: {
-            value: [
-              0x06, //
-              hrm.bpm
-            ],
+            value: [0x06, hrm.bpm],
             notify: true
+          },
+          0x2A38: {
+            value: 0x02,
           }
         }
       });