WiFi.RSSI() returns the signal strength of a Wi-Fi network from -127 (weak) to -1dB (strong) as an
int. Positive return values indicate an error with 1 indicating a Wi-Fi chip error and 2 indicating a time-out error.
// SYNTAX int rssi = WiFi.RSSI(); WiFiSignal rssi = WiFi.RSSI();
WiFi.RSSI() returns an instance of
// SYNTAX WiFiSignal sig = WiFi.RSSI();
If you are passing the RSSI value as a variable argument, such as with Serial.printlnf, Log.info, snprintf, etc. make sure you add a cast:
Log.info("RSSI=%d", (int8_t) WiFi.RSSI()).
This is necessary for the compiler to correctly convert the WiFiSignal class into a number.