From 70063662436ce6ba742a73bccbe253721e4734de Mon Sep 17 00:00:00 2001
From: Ben Nuttall <ben@bennuttall.com>
Date: Fri, 2 Dec 2016 00:02:24 +0000
Subject: [PATCH] Update sourcevalues docs as suggested in lurch's review

---
 docs/examples/led_button_loop.py         |  2 ++
 docs/examples/negated.py                 |  1 +
 docs/examples/random_values.py           |  1 +
 docs/examples/source_value_processing.py | 13 +++++++++++++
 docs/source_values.rst                   | 18 ++++++------------
 5 files changed, 23 insertions(+), 12 deletions(-)
 create mode 100644 docs/examples/source_value_processing.py

diff --git a/docs/examples/led_button_loop.py b/docs/examples/led_button_loop.py
index 8e28368..0b01872 100644
--- a/docs/examples/led_button_loop.py
+++ b/docs/examples/led_button_loop.py
@@ -1,7 +1,9 @@
 from gpiozero import LED, Button
+from time import sleep
 
 led = LED(17)
 button = Button(2)
 
 while True:
     led.value = button.value
+    sleep(0.01)
diff --git a/docs/examples/negated.py b/docs/examples/negated.py
index e7cc2cf..2e5285e 100644
--- a/docs/examples/negated.py
+++ b/docs/examples/negated.py
@@ -4,6 +4,7 @@ from signal import pause
 
 led = LED(4)
 btn = Button(17)
+
 led.source = negated(btn.values)
 
 pause()
diff --git a/docs/examples/random_values.py b/docs/examples/random_values.py
index 99a2572..524e456 100644
--- a/docs/examples/random_values.py
+++ b/docs/examples/random_values.py
@@ -4,5 +4,6 @@ from signal import pause
 
 led = PWMLED(4)
 led.source = random_values()
+led.source_delay = 0.1
 
 pause()
diff --git a/docs/examples/source_value_processing.py b/docs/examples/source_value_processing.py
new file mode 100644
index 0000000..bd2b845
--- /dev/null
+++ b/docs/examples/source_value_processing.py
@@ -0,0 +1,13 @@
+from gpiozero import Button, LED
+from signal import pause
+
+def opposite(values):
+    for value in values:
+        yield not value
+
+led = LED(4)
+btn = Button(17)
+
+led.source = opposite(btn.values)
+
+pause()
diff --git a/docs/source_values.rst b/docs/source_values.rst
index 45d49e5..4b108d9 100644
--- a/docs/source_values.rst
+++ b/docs/source_values.rst
@@ -35,14 +35,8 @@ provided, setting the device's value to each element at a rate specified in the
 .. image:: images/source_values.*
 
 The most common use case for this is to set the source of an output device to
-the values of an input device, like the example above. It is also possible to
-set the source of an output device to the values of another output device (so
-they match):
-
-.. literalinclude:: examples/led_button.py
-
-A more interesting example would be a potentiometer controlling the brightness
-of an LED:
+the values of an input device, like the example above. A more interesting
+example would be a potentiometer controlling the brightness of an LED:
 
 .. literalinclude:: examples/pwmled_pot.py
 
@@ -58,7 +52,7 @@ The device's values can also be processed before they are passed to the
 
 For example:
 
-.. literalinclude:: examples/custom_generator.py
+.. literalinclude:: examples/source_value_processing.py
 
 Alternatively, a custom generator can be used to provide values from an
 artificial source:
@@ -81,11 +75,11 @@ Composite devices
 -----------------
 
 Most devices have a ``value`` range between 0 and 1. Some have a range between
--1 and 1 (e.g. ``Robot``). The ``value`` of a composite device is a namedtuple
-of such values. For example::
+-1 and 1 (e.g. ``Motor``). The ``value`` of a composite device is a namedtuple
+of such values. For example, the ``Robot`` class::
 
     >>> from gpiozero import Robot
-    >>> robot = Robot(left=(14, 15), right=(17, 18)
+    >>> robot = Robot(left=(14, 15), right=(17, 18))
     >>> robot.value
     RobotValue(left_motor=0.0, right_motor=0.0)
     >>> tuple(robot.value)