Use blocking BLE scan for reliable discovery

firmware/esp32/xterra-controller/bms.cpp

@@ -104,13 +104,17 @@ int scanBleDevices(uint32_t scanSeconds) {
     scan->setInterval(100);
     scan->setWindow(99);
 
-    Serial.println("BLE: Scanning...");
+    Serial.print("BLE: Scanning for ");
-    Serial.println("BLE devices:");
+    Serial.print(scanSeconds);
+    Serial.println(" seconds...");
+
+    NimBLEScanResults results = scan->getResults(scanSeconds, false);
 
-    for (uint32_t second = 0; second < scanSeconds; second++) {
-        NimBLEScanResults results = scan->getResults(1, false);
     int resultCount = results.getCount();
 
+    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);
 
@@ -137,37 +141,38 @@ int scanBleDevices(uint32_t scanSeconds) {
         bleScanResults[bleScanResultCount].name = name;
         bleScanResults[bleScanResultCount].rssi = device->getRSSI();
 
-            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++;
     }
 
     scan->clearResults();
 
-        Serial.print(".");
-    }
-
-    Serial.println();
-
     Serial.print("BLE: Devices found: ");
     Serial.println(bleScanResultCount);
 
-    if (bleScanResultCount > 0) {
+    if (bleScanResultCount == 0) {
-        Serial.println("Use: select bms <number>");
+        return bleScanResultCount;
     }
 
+    Serial.println("BLE devices:");
+
+    for (int i = 0; i < bleScanResultCount; i++) {
+        Serial.print(i + 1);
+        Serial.print(") ");
+
+        if (bleScanResults[i].name.length() > 0) {
+            Serial.print(bleScanResults[i].name);
+        } else {
+            Serial.print("(no name)");
+        }
+
+        Serial.print(" | ");
+        Serial.print(bleScanResults[i].address);
+        Serial.print(" | RSSI ");
+        Serial.println(bleScanResults[i].rssi);
+    }
+
+    Serial.println("Use: select bms <number>");
+
     return bleScanResultCount;
 }