Update README.md

Author: SteveMicroCode

README.md

@@ -1,2 +1,19 @@
 # PIC-TM1637-Library-Code
-A library for TM1637 displays that should work with many 8 bit pics
+A library for TM1637 displays that should work with many 8 bit pics.
+
+Developed using Microchip's XC8 compiler and tested on the PIC12F1840
+and 12F18F6410.
+
+I developed the PIC demo code for the TM1637 in my other repositories
+into a generic TM1637 PIC library. The library functions are in file TM1637PIC.c
+and there is also a .h file to include in the application code. 
+
+See the libdemo appication for how to use the library. Note the need to call the
+initialisation function before attempting output using outputInteger()
+
+The library is intended to be resource sparing for use on 8 bit PICs. It does not
+attempt floating point handling or offer full printf() style output capability.
+My demo shows how it can be used to output floating point numbers. Basic rounding and
+zero blanking is possible however.
+
+Steve, July 2023