BLE scan only gets the name of some devices the first scan?

[PeterAndersson]

I have the following code:

Code: Select all

    #include <Arduino.h>
    #include <BLEDevice.h>
    #include <BLEAdvertisedDevice.h>
    
    static void log(String message)
    {
      Serial.println(message);
    }
    
    const char* deviceName = "BLEScanner";
    BLEScan* pBLEScan;
    
    void setup() {
      Serial.begin(115200);
    
      log("Setup!");
    
      BLEDevice::init(deviceName);
      pBLEScan = BLEDevice::getScan(); //create new scan
      pBLEScan->setActiveScan(true); //active scan uses more power, but get results faster
      pBLEScan->setInterval(100);
      pBLEScan->setWindow(99);  // less or equal setInterval value
    
    }
    
    void loop() {
      log("Listing BLE Sensors");
      BLEScanResults foundSensors = pBLEScan->start(30, false);
      int count = foundSensors.getCount();
      for (int i = 0; i < count; i++) {
        BLEAdvertisedDevice bleSensor = foundSensors.getDevice(i);
        String sensorName = bleSensor.getName().c_str();
        String address = bleSensor.getAddress().toString().c_str();
    
        log("Find" + address + " " + sensorName);
    
      }
      log("Sleeping");
      sleep(10);
    }

And when I run it I get the following output:

Setup!
Listing BLE Sensors
Find00:09:b0:09:e7:ca
Find41:59:8f:07:ec:96
Findac:5d:5c:e1:72:89 LM0845
Findc4:7c:8d:6a:36:cf Flower care
Findc4:7c:8d:6a:45:6b Flower care
Findc4:7c:8d:6a:46:2c Flower care
Findde:d5:2a:8e:1e:fd Tile
Sleeping
Listing BLE Sensors
Find00:09:b0:09:e7:ca
Find41:59:8f:07:ec:96
Findac:5d:5c:e1:72:89
Findc4:7c:8d:6a:36:cf
Findc4:7c:8d:6a:45:6b
Findc4:7c:8d:6a:46:2c
Findde:d5:2a:8e:1e:fd Tile
Sleeping
Listing BLE Sensors
Find00:09:b0:09:e7:ca
Find41:59:8f:07:ec:96
Findac:5d:5c:e1:72:89
Findc4:7c:8d:6a:36:cf
Findc4:7c:8d:6a:45:6b
Findc4:7c:8d:6a:46:2c
Findde:d5:2a:8e:1e:fd Tile
... and so on

For some reason i only get the names of some of the devices the first time, is this a known error and what can be done about it?

I have tried to put a **pBLEScan->clearResults();** before i start a scan but that did not help..

I have a Adafruit esp32 feather if that helps.

[orteip94]

I have the same problem. I am trying in every way to solve it but I only get the name at the first scan.
the MAC is always visible, but every time I do a scan only the first time
I get the name, the following times NULL.

Code: Select all

void scanArea()
{
  Serial.print("\n#############################################################");
  Serial.print("\n###### My Address MAC BLE: ");
  Serial.print(MyMAC);
  Serial.print("\n#############################################################");
  pBLEScan = BLEDevice::getScan();
  pBLEScan->setActiveScan(true);  
  BLEScanResults results = pBLEScan->start(1); 
  Serial.println("\n-----------------------------Device--------------------------------");
  
  for (int i = 0; i < results.getCount(); i++) 
  {
    Serial.println("\n_______________________________________________________________________");
    BLEAdvertisedDevice device = results.getDevice(i);
    Serial.print("\nDevice Address ");
    Serial.print(i + 1);
    Serial.print(": ");
    MAC = device.getAddress().toString().c_str();
    Serial.print(MAC);
    Serial.print(" | Rssi: ");
    Rssi_device = device.getRSSI();
    Serial.print(Rssi_device);
    Name = device.getName().c_str();
    Serial.print(" | Nome Device: ");
    Serial.print(Name);
    Manufacturer = device.getManufacturerData().c_str();
    Serial.print(" | Manufacturer Device: ");
    Serial.print(Manufacturer);
}
}

This is a BIG PROBLEM FOR ME!

[ignaciotheodor]

I think this is not a problem of ESP32, but bluetooth.
If you do a scan with your phone, its the same.
Maybe if you increase the scann time, the micro can ask every device for it's name.
Or you should ask for it to the device.
When I scann in my esp32, it shows a lot of devices that my phone doesn't show.