Build check added

README.md

@@ -4,6 +4,12 @@ A place for assorted code ideas for MicroPython.
 mutex: A class providing mutal exclusion enabling interrupt handlers and the main program to
 access shared data in a manner which ensures data integrity.
 
+watchdog: How to access the simpler of the Pyboard's watchdog timers.
+
+radio: A trivial class simplifying the use of the nRF24L01 radio for the case where a wireless
+link between two devices is required.
+
+Buildcheck: Raise an exception if a firmware build is earlier than a given date.
 
 Any code placed here is released under the MIT License (MIT).  
 The MIT License (MIT)  

buildcheck/buildcheck.py

@@ -0,0 +1,12 @@
+# Raise an exception if a firmware build is earlier than a given date
+# buildcheck((2015,10,9))
+def buildcheck(tupTarget):
+    fail = True
+    if 'uname' in dir(os):
+        datestring = os.uname()[3]
+        date = datestring.split(' on')[1]
+        idate = tuple([int(x) for x in date.split('-')])
+        fail = idate < tupTarget
+    if fail:
+        raise OSError('This driver requires a firmware build dated {:4d}-{:02d}-{:02d} or later'.format(*tupTarget))
+