-README.md updated

README.md

@@ -1,4 +1,51 @@
+/***********************************************************/
+/*  _   _             _     ____ ____     ___ ____   ____  */
+/* | |_(_)_ __  _   _| |   / ___|  _ \   |_ _|___ \ / ___| */
+/* | __| | '_ \| | | | |  | |   | | | |   | |  __) | |     */
+/* | |_| | | | | |_| | |__| |___| |_| |   | | / __/| |___  */
+/*  \__|_|_| |_|\__, |_____\____|____/___|___|_____|\____| */
+/*              |___/               |_____|                */
+/***********************************************************/
+
 tinyLCD_I2C
 ===========
 
-Firmware for LCD I2C backpack based on ATtiny84
+Description:
+------------
+tinyLCD_I2C is a Firmware for LCD I2C backpack based on ATtiny84 with an Arduino library as drop-in replacment for the LiquidCrystal library.
+
+Instructions
+------------
+Please make sure to use the TinyWireS library from this repo with the ATtiny implementation from
+http://code.google.com/p/arduino-tiny/
+
+Also you should make the following change in ./hardware/tiny/cores/tiny/wiring.c to improve performance of the TinyWireS library:
+
+ISR(MILLISTIMER_OVF_vect)
+{
+  sei();
+  // copy these to local variables so they can be stored in registers
+  // (volatile variables must be read from memory on every access)
+
+Basically add the line
+  sei();
+to the ISR(MILLISTIMER_OVF_vect) function so that it looks like above excerpt.
+
+See http://forum.boxtec.ch/index.php/topic,2225.msg2845.html#msg2845 for a discussion on this issue.
+
+Boards / PCBs
+-------------
+The boards directory contains a Fritzing THT design on which current development is based and an Eagle 6.x SMD design which is currently in production for first prototypes.
+
+Forum / contact
+---------------
+Issues around the tinyLCD_I2C board and firmware can be discuess here:
+-> http://forum.boxtec.ch/index.php/topic,2225.0.html
+
+Credits
+-------
+Credits go to ..
+.. brohogan for bringing the TinyWireS library to life in the first place.
+.. pylon for fixing all the timing issue and race conditions in above library and enhancing the tinyLCD_I2C greatly (i.e. by adding SPI)
+.. MathiasW for adding a SMD design with reduced size
+