MikroTik Metal 52 ac: Stable 2.4 GHz Link

autochannel.rsc

/system script add name=auto-channel-boot policy=read,write,test source={
  :local iface "wlan1";
  :local cand {2412;2437;2462};
  :local bestFreq 2437;
  :local bestScore 999999;

  :global autoChanDone;
  :if ([:len $autoChanDone] > 0 && $autoChanDone = true) do={
    :log info "[auto-chan] already done, skipping";
    :return;
  }

  :local gotClient false;
  :for i from=1 to=120 do={
    :local n [/interface wireless registration-table print count-only];
    :if ($n > 0) do={ :set gotClient true; :set i 120; } else={ :delay 1; }
  }
  :if ($gotClient) do={
    :log warning "[auto-chan] client detected, scanning (brief disconnect possible)...";
  } else={
    :log warning "[auto-chan] no client after 120s, scanning anyway...";
  }

  :set autoChanDone true;

  :local res [/interface wireless scan $iface duration=5];

  :foreach f in=$cand do={
    :local score 0;

    :foreach r in=$res do={
      :local ch ($r->"channel");
      :if ([:len $ch] = 0) do={ :set ch ($r->"CHANNEL"); }

      :local slash [:find $ch "/"];
      :if ($slash != nil) do={
        :local rf [:tonum [:pick $ch 0 $slash]];

        :local d ($rf - $f); :if ($d < 0) do={ :set d (0 - $d); }
        :if ($d < 25) do={
          :local sig ($r->"sig");
          :if ([:len $sig] = 0) do={ :set sig ($r->"signal-strength"); }
          :if ([:len $sig] = 0) do={ :set sig -100; }

          :set score ($score + 10);
          :local p (90 + $sig); 
          :if ($p < 0) do={ :set p 0; }
          :set score ($score + $p);
        }
      }
    }

    :log info ("[auto-chan] freq " . $f . " score " . $score);
    :if ($score < $bestScore) do={ :set bestScore $score; :set bestFreq $f; }
  }

  :log warning ("[auto-chan] choosing " . $bestFreq . " score=" . $bestScore);
  /interface wireless set $iface frequency=$bestFreq;
}

setup.md

{paste above script}

# run at boot
/system scheduler add name=run-auto-chan-after-client start-time=startup on-event=auto-channel-after-client policy=read,write,test

# test run
/system script run auto-channel-after-client

/system script remove [find name="auto-channel-after-client"]