Adding battery voltage measurement

bedroom_lilygo_t7v13.yaml

@@ -20,7 +20,7 @@ ota:
 <<: !include standard_mqtt_deepsleep.yaml
 deep_sleep:
         run_duration: 20s
-        sleep_duration: 40s #24h
+        sleep_duration: 240s #24h
         esp32_ext1_wakeup:
                 pins:
                   - 33 #middle button
@@ -40,6 +40,13 @@ sensor:
     accuracy_decimals: 0
     lambda: |-
             return id(wake_up_reason);
+  - platform: adc
+    pin: GPIO39
+    attenuation: 11db
+    name: "Battery Voltage"
+    update_interval: 10s
+    filters:
+      - multiply: 0.83 #(3.24/3.90)
 
 binary_sensor:
   - platform: gpio