add ssid channel

README.md

@@ -34,15 +34,16 @@ Name | Description | Default
 ---|---|---
 DELAY | Number of seconds between scans | 600 (10 minutes)
 WLAN | Interface to use | wlan0
+SSID | SSID name | 
 MQTT_URL | Mqtt broker IP | 192.168.0.100
 MQTT_TOPIC | Mqtt topic | wifi/scan
 
 ## Home assiatnt sensor
 
-The application publish the number of discovered networks in the state field, and total number of networks per channel in the channels field (index 0 is not used, channel 1 starts from index 1)
+The application publish the number of discovered networks in the state field, and total number of networks per channel in the channels field. The ssid channel will be set with the channle of the specified ssid (0 if not specified).
 
 ```
-{"state":6,"channels":[0,0,0,0,0,0,0,4,0,0,0,2,0,0]}
+{"state":6,"channels":[0,0,0,0,0,0,4,0,0,0,2,0,0]}
 ```
 
 The following sensor can be used to track the number of networks in wifi channel 7:
@@ -51,8 +52,9 @@ The following sensor can be used to track the number of networks in wifi channel
 sensor:
   - platform: mqtt
     name: Wifi channel 7
+    icon: mdi:wifi
     state_topic: "wifi/scan"
-    value_template: "{{ value_json['channels'][7] }}"
+    value_template: "{{ value_json['channels'][6] }}"
 ```
 
 ## Wifi channels and frequency

app.sh

@@ -14,16 +14,23 @@ mqtt_topic="${MQTT_TOPIC:-wifi/scan}"
 
 while true
 do
-  channels=$(iwlist $wlan scan | bash scan.sh)
+  result=$( iwlist $wlan scan | bash scan.sh )
+  for i in ${result[@]}; do
+    channels+=($i)
+  done
 
+  # Extract ssid channel and reset first item
+  ssid_channel=${channels[0]}
+  channels=("${channels[@]:1}")
+
   # Total number of networks
   total=0
   for i in ${channels[@]}; do
     let total+=$i
   done
 
   # Publish
-  message=`jo state=$total channels=$(jo -a ${channels[@]})`
+  message=`jo state=$total ssid_channel=$ssid_channel channels=$(jo -a ${channels[@]})`
   mosquitto_pub -h $mqtt_url -t $mqtt_topic -m $message
 
   # Wait before next scan

scan.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 
-# Init networks detetced per channel (total 14 channels, chanel in index 0 is not used)
-channels=(0 0 0 0 0 0 0 0 0 0 0 0 0 0)
+# Init result (ssid channel, 13 channels)
+result=(0 0 0 0 0 0 0 0 0 0 0 0 0 0)
 
 # Scan and parse
 while IFS= read -r line; do
@@ -19,11 +19,16 @@ while IFS= read -r line; do
   [[ "$line" =~ Encrypt ]] && enc=${line##*key:}
   [[ "$line" =~ ESSID ]] && {
       essid=${line##*ID:}
+      # Accumlate networks onin channel
+      result[$chn]=$((result[$chn]+1));
+      # Set ssid channel (if specified)
+      if [[ "$essid" == "\"$SSID\"" ]]; then
+        result[0]=$chn
+      fi
       # echo " $mac  $essid  $frq  $chn  $qual  $lvl  $enc"  # output after ESSID
-      # Accumlate networks on channels
-      channels[$chn]=$((channels[$chn]+1))
   }
+
 done
 
 # Return channels scan result
-echo ${channels[@]}
+echo "${result[@]}"