Add WiFi Signal Strength sensor (#35)

esphomeyaml/components/sensor/wifi_signal.py

@@ -0,0 +1,22 @@
+import voluptuous as vol
+
+import esphomeyaml.config_validation as cv
+from esphomeyaml.components import sensor
+from esphomeyaml.const import CONF_MAKE_ID, CONF_NAME, CONF_UPDATE_INTERVAL
+from esphomeyaml.helpers import App, Application, variable
+
+MakeWiFiSignalSensor = Application.MakeWiFiSignalSensor
+
+PLATFORM_SCHEMA = sensor.PLATFORM_SCHEMA.extend({
+    cv.GenerateID(CONF_MAKE_ID): cv.declare_variable_id(MakeWiFiSignalSensor),
+    vol.Optional(CONF_UPDATE_INTERVAL): cv.positive_time_period_milliseconds,
+}).extend(sensor.SENSOR_SCHEMA.schema)
+
+
+def to_code(config):
+    rhs = App.make_wifi_signal_sensor(config[CONF_NAME], config.get(CONF_UPDATE_INTERVAL))
+    make = variable(config[CONF_MAKE_ID], rhs)
+    sensor.setup_sensor(make.Pwifi, make.Pmqtt, config)
+
+
+BUILD_FLAGS = '-DUSE_WIFI_SIGNAL_SENSOR'