add wifi signal strength sensor

flake.nix

@@ -14,6 +14,7 @@
           src = ./src;
           propagatedBuildInputs = with pkgs.python311Packages; [
             pkgs.light
+            pkgs.wirelesstools
             pkgs.xorg.xset
 
             coloredlogs
@@ -28,6 +29,7 @@
           name = "development shell";
           nativeBuildInputs = with pkgs.python311Packages; [
             pkgs.light
+            pkgs.wirelesstools
             pkgs.xorg.xset
 
             coloredlogs

src/ha-kiosk-agent

@@ -68,7 +68,8 @@ async def main():
         'display_brightness':   sensor.DisplayBrightnessSensor(device, dbm),
         'ip_address':           sensor.IPAddressSensor(device),
         'last_boot':            sensor.LastBootSensor(device),
-        'temperature':          sensor.TemperatureSensor(device)
+        'temperature':          sensor.TemperatureSensor(device),
+        'wifi_signal':          sensor.WifiSignalStrengthSensor(device)
     };
 
     tasks.append(sensor_loop(logger, sensor_entities))

src/sensor.py

@@ -1,5 +1,6 @@
 import logging
 import psutil
+import re
 import socket
 import subprocess
 import time
@@ -29,7 +30,8 @@ class BatterySensor():
         charger_connected_info = ha_mqtt_discoverable.sensors.BinarySensorInfo(
             name="Battery charger connected",
             device=device.get_mqtt_device(),
-            unique_id=f'{device.get_device_id()}_battery_charger_connected')
+            unique_id=f'{device.get_device_id()}_battery_charger_connected',
+            device_class='plug')
         charger_connected_settings = ha_mqtt_discoverable.Settings(mqtt=device.get_mqtt_settings(), entity=charger_connected_info, manual_availability=True)
         self.connected_entity = ha_mqtt_discoverable.sensors.BinarySensor(charger_connected_settings)
         self.connected_entity.set_availability(True)
@@ -207,3 +209,32 @@ class TemperatureSensor():
 
         self.value = newValue
 
+class WifiSignalStrengthSensor():
+    value = -1
+    mqtt_sensor = None
+
+    def __init__(self, device: Device):
+        wifi_strength_info = ha_mqtt_discoverable.sensors.SensorInfo(
+            name="Wifi Signal Strength",
+            device=device.get_mqtt_device(),
+            unique_id=f'{device.get_device_id()}_wifi_signal_strength',
+            device_class='signal_strength',
+            unit_of_measurement='dBm')
+        wifi_strength_settings = ha_mqtt_discoverable.Settings(mqtt=device.get_mqtt_settings(), entity=wifi_strength_info, manual_availability=True)
+        self.mqtt_sensor = ha_mqtt_discoverable.sensors.Sensor(wifi_strength_settings)
+        self.update_value()
+
+    def update_value(self):
+        res = subprocess.run(['iwconfig'], capture_output=True)
+        m = re.findall('Signal level=(-[0-9]+) dBm', res.stdout.decode('utf-8'))
+        if len(m) == 0:
+            self.mqtt_sensor.set_availability(False)
+            return
+        else:
+            self.mqtt_sensor.set_availability(True)
+
+        newValue = float(m[0])
+        if newValue != self.value:
+            self.mqtt_sensor.set_state(newValue)
+
+        self.value = newValue