/*** 8 LED I2C LED Example Released into public domain by Nick D. (nick@nick125.com) Feel free to do what you please with this code, but if you have any revisions, I'd kindly request that you send them to me :-) ***/ #include <Wire.h> #define PCF8574A_PORT 56 void setup() { Wire.begin(); Serial.begin(9600); } void loop() { Wire.beginTransmission(PCF8574A_PORT); Wire.send(B11111111); Wire.endTransmission(); delay(1000); Wire.beginTransmission(PCF8574A_PORT); Wire.send(B0000000); Wire.endTransmission(); delay(1000); }