Merge pull request #73 from fbrand-new/feat/roam.sh

Wifi roaming

bin/CMakeLists.txt

@@ -6,5 +6,8 @@
 ################################################################################
 
 file(GLOB ros2_launch ${CMAKE_CURRENT_SOURCE_DIR}/ros2_launch.sh)
+file(GLOB roam ${CMAKE_CURRENT_SOURCE_DIR}/roam.sh)
 
-yarp_install(FILES ${ros2_launch} DESTINATION bin)
+
+yarp_install(FILES ${ros2_launch} DESTINATION bin)
+yarp_install(FILES ${roam} DESTINATION bin)

bin/roam.sh

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+# This is an utility to make the R1 robot roam more aggressively than it would do by default
+
+if [ "$EUID" -ne 0 ]
+  then echo "Please run the script like this:
+
+sudo -E su # to keep the environment variables
+roam.sh
+"
+  exit
+fi
+
+
+# Name of the SSID
+ESSID=$(iwgetid -r)
+
+# These frequencies are expressed in MHz and they are the ones used by the APs
+FREQ=$AP_FREQUENCIES
+
+if [ -z "$FREQ" ]
+then
+    echo 'Please set the AP_FREQUENCIES environment variable like "5000,5010,...,5040"'
+    exit -1
+fi
+
+echo "Scanning only on these freqs: $FREQ Mhz"
+
+SLEEP_DURATION=4
+DETECTION_THRESHOLD=-70
+
+while [[ true ]]; do
+
+    IW_OUT=$(iwconfig 2>/dev/null $INTERFACE)
+    CURRENT_AP=$(echo "$IW_OUT" | grep "Access Point" | sed -E 's/.*Point: (.*)/\1/' | grep -oE '([0-9A-Fa-f]{2}:){5}[0-9A-Fa-f]{2}')
+    DB=$(echo $IW_OUT | grep level | sed -E 's/.*Signal level=(-[0-9]+).*/\1/')
+    echo "Currently connected to $CURRENT_AP with strenght $DB db"
+
+    if [[ $DB -le $DETECTION_THRESHOLD ]]
+    then
+
+        BEST_AP=$(sudo wpa_cli -i scan_results | grep -w $ESSID | sort -nrk3 | awk -v th="$DETECTION_THRESHOLD" '$3>=th {print $1}' | head -n1)
+        if [[ x"$BEST_AP" == "x" ]] || [[ "${BEST_AP^^}" == "${CURRENT_AP^^}" ]]
+        then
+            # Since there is no better AP to connect to, we scan for new APs
+            echo "There is still no AP guaranteeing a signal > ${DETECTION_THRESHOLD} db"
+            RET=$(sudo wpa_cli -i scan freq=${FREQ})
+            echo $RET
+        else
+            # We see a better AP to connect to
+            echo "Best AP is $BEST_AP. Roaming"
+            sudo wpa_cli roam $BEST_AP
+            sleep $SLEEP_DURATION # Arbitrary value to wait for the connection to be established without triggering a scan
+        fi
+    fi
+
+    sleep $SLEEP_DURATION
+
+done