README.md
PCA9555

Arduino Library to approach PCA9555 I2C expander with digitalRead, digitalWrite, pinMode and functions.
Implemented begin() to check connection with PCA9555 and optional interrupt functionality.

Installation:


a) Just download the zip file
b) move PCA9555_LIB to the Users Arduino library (usually My documents\Arduino\Libraries)
c) Create a new sketch and copy the example file into your sketch
d) Compile, download and done.


Support functions:


pinMode() same as standard Arduino
digitalRead() same as Arduino
digitalWrite() same as Arduino
begin() checks if PCA9555 is responsive
pinStates() ISR retrieves state of all I/O pins
stateOfPin()  returns the state of a particular pin
setClock() sets clock speed


Additional

The code supports either pinnumbers 0 - 15 or ED0 - ED15. This to stay more or less in sync with Arduino.
alertISR() is used to point to the actual ISR for the use of attachInterrupt() from Arduino.