Attempt 2

apps/bootbthomebatt/boot.js

@@ -1,10 +1,39 @@
-(() => {
-  var btHomeSequenceNo = 0;
-  function advertiseBTHomeBattery() {
-    require("ble_advert").set(0xFCD2, [0x40,0x00,btHomeSequenceNo,0x01,E.getBattery()]);
-    btHomeSequenceNo = (btHomeSequenceNo + 1) & 255;
-  }
+var btHomeBatterySequence = 0;
 
-  setInterval(advertiseBTHomeBattery, 5 * 60 * 1000);
-  advertiseBattery();
-})();
+function advertiseBTHomeBattery() {
+  var advert = [ 0x40, /* BTHome Device Information
+              bit 0: "Encryption flag"
+              bit 1-4: "Reserved for future use"
+              bit 5-7: "BTHome Version" */
+
+              0x00, // Sequence number
+              btHomeBatterySequence,
+
+              0x01, // Battery, 8 bit
+              E.getBattery()
+  ];
+
+  if(Array.isArray(Bangle.bleAdvert)){
+    var found = false;
+    for(var ad in Bangle.bleAdvert){
+      if(ad[0xFCD2]){
+        ad[0xFCD2] = advert;
+        found = true;
+        break;
+      }
+    }
+    if(!found)
+      Bangle.bleAdvert.push({ 0xFCD2: advert });
+  } else {
+    Bangle.bleAdvert[0xFCD2] = advert;
+  }
+  NRF.setAdvertising(Bangle.bleAdvert);
+  btHomeBatterySequence = (btHomeBatterySequence + 1) & 255;
+}
+
+if (!Bangle.bleAdvert) Bangle.bleAdvert = {};
+setInterval(function() {
+  advertiseBTHomeBattery();
+}, 300000); // update every 5 min
+
+advertiseBTHomeBattery();