Add modbus sensor page

source/components/sensor.modbus.markdown

@@ -0,0 +1,52 @@
+---
+layout: page
+title: "Modbus sensors support"
+description: "Instructions how to integrate Modbus sensors into Home Assistant."
+date: 2015-08-30 23:38
+sidebar: false
+comments: false
+sharing: true
+footer: true
+---
+
+<img src='/images/supported_brands/modbus.png' class='brand pull-right' />
+The modbus sensor platform allows you to gather data from your [Modbus](http://www.modbus.org/) sensors.
+
+To use your Modbus sensors in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yml entry
+sensor:
+  platform: modbus
+  slave: 1
+  registers:
+    16:
+      name: My integer sensor
+      unit: C
+    24:
+      bits:
+        0:
+          name: My boolean sensor
+        2:
+          name: My other boolean sensor
+  coils:
+    0:
+      name: My coil switch
+```
+
+Configuration variables:
+
+- **slave** (*Required*): The number of the slave (ignored and can be omitted if not serial Modbus).
+- **registers** array (*Required*): The array contains a list of relevant registers to read from.
+  - **number of register** (*Required*): Listing relevant bits. It must contain a `bits` section.
+    - **bits** array (*Required*): Listing relevant bits. It must contain a `bits` section.
+      - **name** (*Required*): Name of the sensor.
+      - **unit** (*Required*): Unit to attach to value (optional, ignored for boolean sensors).
+- **coils** (*Optional*): A list of relevant coils to read from/write to
+  - **number of coil** array (*Required*): 
+    - **name** (*Required*): Name of the coil.
+
+<p class='note warning'>
+Each named register will create an integer sensor and each named bit will create a boolean sensor.
+</p>
+