Merge lp:~pwlars/uci-phone-masher/offset-readme into lp:uci-phone-masher

[Paul Larson]

Readme for the new offset support in uci-phone-masher

=== modified file 'README.rst'
--- README.rst	2015-03-31 18:50:28 +0000
+++ README.rst	2016-04-28 07:57:01 +0000
@@ -73,6 +73,24 @@
 	    "13": "off",
 	    "14": "off",
 	    "15": "off"
+	  },
+	  "offsets": {
+	    "0": 0,
+	    "1": 0,
+	    "2": 0,
+	    "3": 0,
+	    "4": 0,
+	    "5": 0,
+	    "6": 0,
+	    "7": 0,
+	    "8": 0,
+	    "9": 0,
+	    "10": 0,
+	    "11": 0,
+	    "12": 0,
+	    "13": 0,
+	    "14": 0,
+	    "15": 0
 	  }
 	}
 
@@ -81,7 +99,8 @@
 
 	$ curl http://127.0.0.1:8000/button/3
 	{
-	  "button_states": "off"
+	  "button_states": "off",
+      "offset": 0
 	}
 
 To set the state of a button, send a POST request with the desired state set, like so::
@@ -89,6 +108,7 @@
 	$ curl --data state=on http://127.0.0.1:8000/button/3
 	{
 	  "button_states": "on"
+      "offset": 0
 	}
 
 ..the service returns the new state of the button.
@@ -112,6 +132,44 @@
 
 	$ curl --data state=off http://127.0.0.1:8000/button/0
 
+Setting offsets
+===============
+The default rotation of the servo, along with proper calibration, should 
+push the button on the device in most cases.  However, if adjustments are 
+needed, they can be set for each port separately.::
+
+    $ curl localhost:8000/button/3 --data offset=-10
+
+A negative offset will cause the servo to rotate more, in order to push the 
+button - effectively pushing it harder. A positive offset will cause the 
+servo to rotate less in order to push the button.  For reference, the default 
+"off" position is at 300, and the default "pressed" position is 193.
+
+The environment variable UCI_PHONE_MASHER_CONFIG may be used to specify the 
+path to a json config file for the offsets. It should be formatted like this::
+
+    {
+      "0": 0,
+      "1": 0,
+      "2": 0,
+      "3": 0,
+      "4": 0,
+      "5": 0,
+      "6": 0,
+      "7": 0,
+      "8": 0,
+      "9": 0,
+      "10": 0,
+      "11": 0,
+      "12": 0,
+      "13": 0,
+      "14": 0,
+      "15": 0
+    }
+
+If the config file is specified in the environment, then any modifications to 
+offsets will automatically be saved to the same file
+
 Creating a Bootable Image for Raspberry PI 2
 ============================================