Add dedicated scratch-space header so that we can track where these are still used

scratch_space.h

@@ -0,0 +1,13 @@
+/**
+ * The Arduino, unlike C/C++ on a regular computer with gigabytes of RAM, has very little memory.
+ * We have to be very careful with variables that are declared inside the functions as they are 
+ * created in a memory region called the stack. The stack has just a few bytes of space on the Arduino
+ * if you declare large strings inside functions, they can easily exceed the capacity of the stack
+ * and mess up your programs. 
+ * We circumvent this by declaring a few global buffers as  kitchen counters where we can 
+ * slice and dice our strings. These strings are mostly used to control the display or handle
+ * the input and output from the USB port. We must keep a count of the bytes used while reading
+ * the serial port as we can easily run out of buffer space. This is done in the serial_in_count variable.
+ */
+
+extern char c[30], b[128];