Ble runtime error when looking for AdvertiserServiceUuids

[Fabio_670]

Hi,
I need to know when one of my several BLE devices goes far from my phone. Instead of scanning, since I know the MAC of all devices, I’m trying to ask the devices for some properties to see if the are alive or not. I’m trying to get AdvertiserServiceUuids either with mac either after a scan result but I alway receive “Ble runtime error …getScanRecord() on a null object reference”.
Can you please tell me if I’m wrong or what?
Can I do a l2ping or ask for something different?
Thanks

[Juan_Antonio]

In this discussion, the app sends a message and ESP32 returns a response.

BLE ESP32. Bluetooth. Send. Receive. Arduino IDE. Multitouch

3.- App sends text and receives random number. With Clock. p110i_esp32_ble_recibir.aia (221.0 KB) [appinventoresp32ble91] Write and Send a text. Show in Serial Monitor. ESP sends a random number. With Clock. Look TimerInterval and Delay. [appinventoresp32ble4i] /* Based on Neil Kolban example for IDF: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/tests/BLE%20Tests/SampleWrite.cpp Ported to Arduino ESP32 by Evandro Copercini */ // Modificado por Juan Antonio Vil…

Another idea would be for the BLE device to send its status from time to time through the RegistryForStrings procedure.

[Fabio_670]

Thank you, I will try this.