B4R Question ESP8266 RSSI for particular AP

[BertI]

Anyone know if there is a way to get the RSSI value for a given link between the ESP8266 and some access point to which it is connected without having to do a whole network scan process? For example to be able to regularly check the connection strength to the router in a non onerous way

 

[thetahsk]

..forum search is working

https://www.b4x.com/android/forum/threads/wifi-signal-stength.104240/#post-653418

 

[BertI]

Indeed, but this just mentions using full network scan (as I understand it) which takes quite a bit of time. Just wondered if there was some way to get the RSSI level only of the network currently connected to a bit more neatly and less power consuming

 

[thetahsk]

Indeed, but this just mentions using full network scan (as I understand it) which takes quite a bit of time. Just wondered if there was some way to get the RSSI level only of the network currently connected to a bit more neatly and less power consuming

Use inline c with WiFi.RSSI() function and convert this example :

https://github.com/tttapa/Projects/blob/master/ESP8266/WiFi/RSSI-WiFi-Quality/RSSI-WiFi-Quality.ino

 

[BertI]

Thank you for that pointer.

So for anyone else who bumbles through these things like myself, the following looks to do the job:

#if C
void GetRSSI (B4R::Object* o) {
b4r_main::_rssi = WiFi.RSSI();
}
#End if

Where you first declare a variable to collect the RSSI value:

Private RSSI as Int

and then

RunNative("GetRSSI", Null)

will get the RSSI value as a -dB value into the variable RSSI

 

[thetahsk]

Thank you for that pointer.
...

Before calling Wifi.RSSI() check if you are connected with WiFi.status() = WL_CONNECTED

 

[BertI]

Yes that's a good point. I tried it without being connected and got a value back of 31 (that's plus 31) so I guess also an indicator in itself that you are not connected - though it was just one test so can't assume, without knowing the underlying detail, that this is a reliable alternative to checking if connected first.

 

[thetahsk]

Yes that's a good point.....

Convert this code snippet from above to B4R and check the return value against -1

/*
   Return the quality (Received Signal Strength Indicator)
   of the WiFi network.
   Returns a number between 0 and 100 if WiFi is connected.
   Returns -1 if WiFi is disconnected.
*/
int getQuality() {
  if (WiFi.status() != WL_CONNECTED)
    return -1;
  int dBm = WiFi.RSSI();
  if (dBm <= -100)
    return 0;
  if (dBm >= -50)
    return 100;
  return 2 * (dBm + 100);
}