ESP8266 Wemos D1 Retrieving Wrong AP Mac Address

Question

Using WiFi.BSSID and WiFi.BSSIDstr gives me some weird mac address.

the code is:

#include "ESP8266WiFi.h"
#include "ESP8266WiFiScan.h"

void setup() {
Serial.begin(115200);
//WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);
Serial.println("Setup done");
Serial.println(WiFi.macAddress());
}

void loop() {
   int n=WiFi.scanNetworks();
   Serial.println(n);
   for (int network = 0; network < n; network++){
      Serial.println(WiFi.SSID(network));
      Serial.println(WiFi.RSSI(network));
      uint8_t* mac=WiFi.BSSID(n);
      char APmac[13];
      APmac[0]=0;
      for (int i=0; i<6;i++) {
        char buffer[3];
        sprintf(buffer, "%02x", mac[i]);
        strncpy((char *)(APmac+(i*2)), buffer, 3);
        Serial.print("["); Serial.print(i); Serial.print("]"); Serial.println(buffer);
      }
      Serial.println(APmac);
      Serial.println(WiFi.BSSIDstr(n));

  }
  Serial.println();
  Serial.println();
  delay(10000);
}

The current output is 6D:98:C9:00:00:00 which is completely off. It duplicates this output for other APs too. Is this a hardware problem? I've seen other people using the same codes and it works for them. For reference WiFi.SSID(); and WiFi.RSSI(); both spits out correctly.

edit: I was testing both output to see which ever one was correct and unfortunately they're both wrong

Is your for loop duplicated on purpose: "for(int i=0; i<6; i++){for( int i=0; i<6;i++){" Also, your code prints the segmented string, and then the output of BSSIDstr() -- are both the same output (and both wrong?) — jose can u c
– jose can u c, Commented Sep 12, 2017 at 19:24
@josecanuc The duplication was done accidentally. I put in both to show that I've used both and they both put out the same wrong address. — Display name
– Display name, Commented Sep 12, 2017 at 19:56
What value do you expect, and how was the correct value determined? — jose can u c
– jose can u c, Commented Sep 12, 2017 at 20:03
I do have the AP mac address values with me already. I'm expecting the result from the two functions to be the same. — Display name
– Display name, Commented Sep 12, 2017 at 20:06
What is the expected value? Your code builds the APmac (or APMAC; you are inconsistent in the variable name), but you never print it. — jose can u c
– jose can u c, Commented Sep 12, 2017 at 20:35

jose can u c · Accepted Answer · 2017-09-13 02:24:44Z

0

This seems wrong, you are trying to get String to interpret a byte, but are passing in a pointer to a byte:

String digit = String(*mac, HEX);

Try changing your example to:

uint8_t* mac=WiFi.BSSID();              // Gather the byte array
String APmac;
for (int i=0; i<6;i++) {
   String digit = String(mac[i], HEX);  // String() should see an int, not a pointer to a byte, with the directive to print it in HEX format
   if (digit.length() <2)
     APmac += String("0")+digit;        // Corrected capitalization error
   else
     APmac +=digit;                     // Corrected capitalization error
   //mac++;                             // Not necessary
   Serial.print("["); Serial.print(i); Serial.print("]");
   Serial.println(mac[i], HEX);
}
Serial.println(APmac);                  // Print the constructed String
Serial.println(WiFi.BSSIDstr());        // Print the pre-formatted string

Consider not using the String object, which may help condense the code a bit:

uint8_t* mac=WiFi.BSSID();
char APmac[13];
APmac[0]=0;
for (int i=0; i<6;i++) {
   char buffer[3];
   sprintf(buffer, "%02x", mac[i]);
   strncpy((char *)(APmac+(i*2)), buffer, 3);
   Serial.print("["); Serial.print(i); Serial.print("]"); Serial.println(buffer);
}
Serial.println(APmac);
Serial.println(WiFi.BSSIDstr());

answered Sep 13, 2017 at 2:24

jose can u c

6,9742 gold badges17 silver badges27 bronze badges

your suggested code did help clean up a bit. I think I found a problem: when I connect to a certain AP and ask for the mac address, I get the right one. I've been using WiFi.scanNetworks(); and been trying to retrieve mac address for each AP that's scanned, however it doesn't seem to like that at all. Any thoughts on it?

Display name
– Display name

2017-09-13 12:19:23 +00:00
Commented Sep 13, 2017 at 12:19
Post your code for how you use WiFi.scanNetworks(); and so on, since it may be that there are bugs in the code you are using, which we cannot know about without seeing.

jose can u c
– jose can u c

2017-09-13 12:50:14 +00:00
Commented Sep 13, 2017 at 12:50
Edited the question to put the whole code

Display name
– Display name

2017-09-13 13:20:37 +00:00
Commented Sep 13, 2017 at 13:20
And what is the actual output or error you get from that code.

jose can u c
– jose can u c

2017-09-13 13:25:57 +00:00
Commented Sep 13, 2017 at 13:25
god... I found the bug. Instead of "n" I should have put "network"....

Display name
– Display name

2017-09-13 13:26:23 +00:00
Commented Sep 13, 2017 at 13:26

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