Use BLE scan callbacks for device discovery

firmware/esp32/xterra-controller/bms.cpp

@@ -68,6 +68,58 @@ static void handleNotify(
 }
 
 
+
+class BleScanCallbacks : public NimBLEScanCallbacks {
+    void onResult(const NimBLEAdvertisedDevice* device) override {
+        if (bleScanResultCount >= MAX_BLE_SCAN_RESULTS) {
+            return;
+        }
+
+        String address = device->getAddress().toString().c_str();
+
+        for (int i = 0; i < bleScanResultCount; i++) {
+            if (bleScanResults[i].address == address) {
+                bleScanResults[i].rssi = device->getRSSI();
+
+                if (bleScanResults[i].name.length() == 0 && device->haveName()) {
+                    bleScanResults[i].name = device->getName().c_str();
+                }
+
+                return;
+            }
+        }
+
+        String name = "";
+        if (device->haveName()) {
+            name = device->getName().c_str();
+        }
+
+        bleScanResults[bleScanResultCount].address = address;
+        bleScanResults[bleScanResultCount].name = name;
+        bleScanResults[bleScanResultCount].rssi = device->getRSSI();
+
+        Serial.print(logTimestamp());
+        Serial.print(" BLE: found ");
+        Serial.print(bleScanResultCount + 1);
+        Serial.print(") ");
+
+        if (name.length() > 0) {
+            Serial.print(name);
+        } else {
+            Serial.print("(no name)");
+        }
+
+        Serial.print(" | ");
+        Serial.print(address);
+        Serial.print(" | RSSI ");
+        Serial.println(device->getRSSI());
+
+        bleScanResultCount++;
+    }
+};
+
+static BleScanCallbacks bleScanCallbacks;
+
 void pauseBmsReconnect(uint32_t pauseMs) {
     bmsReconnectPausedUntil = millis() + pauseMs;
 }
@@ -103,17 +155,24 @@ int scanBleDevices(uint32_t scanSeconds) {
     bleScanResultCount = 0;
 
     NimBLEScan* scan = NimBLEDevice::getScan();
+    scan->setScanCallbacks(&bleScanCallbacks, false);
     scan->setActiveScan(true);
     scan->setInterval(100);
     scan->setWindow(99);
     scan->clearResults();
 
     Serial.print(logTimestamp());
-    Serial.print(" BLE: Starting continuous scan for ");
+    Serial.print(" BLE: Scanning for ");
     Serial.print(scanSeconds);
     Serial.println(" seconds...");
 
-    scan->start(scanSeconds, false, false);
+    bool started = scan->start(scanSeconds, false, false);
+
+    if (!started) {
+        Serial.print(logTimestamp());
+        Serial.println(" BLE: scan failed to start");
+        return 0;
+    }
 
     unsigned long startMs = millis();
     unsigned long durationMs = scanSeconds * 1000UL;
@@ -130,50 +189,14 @@ int scanBleDevices(uint32_t scanSeconds) {
             Serial.print(elapsed / 1000);
             Serial.print("/");
             Serial.print(scanSeconds);
-            Serial.println(" sec");
+            Serial.print(" sec, devices ");
+            Serial.println(bleScanResultCount);
         }
 
         delay(50);
     }
 
     scan->stop();
-
-    NimBLEScanResults results = scan->getResults();
-    int resultCount = results.getCount();
-
-    Serial.print(logTimestamp());
-    Serial.print(" BLE: Raw devices seen: ");
-    Serial.println(resultCount);
-
-    for (int i = 0; i < resultCount && bleScanResultCount < MAX_BLE_SCAN_RESULTS; i++) {
-        const NimBLEAdvertisedDevice* device = results.getDevice(i);
-
-        String address = device->getAddress().toString().c_str();
-        bool alreadySeen = false;
-
-        for (int existing = 0; existing < bleScanResultCount; existing++) {
-            if (bleScanResults[existing].address == address) {
-                alreadySeen = true;
-                break;
-            }
-        }
-
-        if (alreadySeen) {
-            continue;
-        }
-
-        String name = "";
-        if (device->haveName()) {
-            name = device->getName().c_str();
-        }
-
-        bleScanResults[bleScanResultCount].address = address;
-        bleScanResults[bleScanResultCount].name = name;
-        bleScanResults[bleScanResultCount].rssi = device->getRSSI();
-
-        bleScanResultCount++;
-    }
-
     scan->clearResults();
 
     Serial.print(logTimestamp());
@@ -181,6 +204,7 @@ int scanBleDevices(uint32_t scanSeconds) {
     Serial.println(bleScanResultCount);
 
     if (bleScanResultCount == 0) {
+        Serial.println("No BLE devices found.");
         return bleScanResultCount;
     }