diff --git a/tests/README.md b/tests/README.md
index 2fbeced..d51dc24 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -1,3 +1,56 @@
-# Arduino Client for MQTT Test Suite
+## Arduino Client for MQTT Test Suite
+
+This is a regression test suite for the `PubSubClient` library.
+
+Without a suitable arduino plugged in, the test suite will only check the
+example sketches compile cleanly against the library.
+
+With an arduino plugged in, each sketch that has a corresponding python
+test case is built, uploaded and then the tests run.
+
+## Dependencies
+
+ - Python 2.7+
+ - [INO Tool](http://inotool.org/) - this provides command-line build/upload of Arduino sketches
+
+## Running
+
+Without a suitable arduino plugged in, the test suite will only check the
+example sketches compile cleanly against the library.
+
+With an arduino plugged in, each sketch that has a corresponding python
+test case is built, uploaded and then the tests run. 
+ 
+   $ python testsuite.py
+
+## What it does
+
+For each example sketch, `sketch.ino`, the suite looks for a matching test case
+`testcases/sketch.py`.
+
+The test case must follow these conventions:
+ - sub-class `unittest.TestCase`
+ - provide the class methods `setUpClass` and `tearDownClass` (TODO: make this optional)
+ - all test method names must begin with `test_`
+ 
+The suite will call the `setUpClass` method _before_ uploading the sketch. This
+allows any test setup to be performed before the the sketch runs - such as connecting
+a client and subscribing to topics.
+
+
+## Settings
+
+The file `testcases/settings.py` is used to config the test environment.
+
+ - `server_ip` - the IP address of the broker the client should connect to
+ - `arduino_ip` - the IP address the arduino should us
+
+Before each sketch is compiled, these values are automatically substituted in. To
+do this, the suite looks for lines that match the following:
+
+     byte server[] = {
+     byte ip[] = {
+
+
 
 
diff --git a/tests/testsuite.py b/tests/testsuite.py
index c86f707..0a8e70d 100644
--- a/tests/testsuite.py
+++ b/tests/testsuite.py
@@ -76,9 +76,9 @@ class Sketch(object):
     fin.close()
     fout = open(os.path.join(self.w.build_dir,"src","sketch.ino"),"w")
     for l in lines:
-      if re.match(r"^byte server\[\]",l):
+      if re.match(r"^byte server\[\] = {",l):
         fout.write("byte server[] = { %s };\n"%(settings.server_ip.replace(".",", "),))
-      elif re.match(r"^byte ip\[\]",l):
+      elif re.match(r"^byte ip\[\] = {",l):
         fout.write("byte ip[] = { %s };\n"%(settings.arduino_ip.replace(".",", "),))
       else:
         fout.write(l)