I compiled and uploaded WiFiScan to my ESP32 unit, but I can't get APs. I usually get this output:
scan start
scan done
no networks found
Occasionally I manage to get one AP, but with a very weak signal.
When I check the WiFi with my notebook I see about 20 APs.
Do I have to use an external antenna with ESP32 boards?
I have this board here:
https://de.aliexpress.com/store/product/ESP32-DevKit-ESP32-WiFi-Bluetooth-Development-Board-ESP-WROOM-32-Dual-Cores-Board-with-Ultra-Low/1048722_32802182371.html