I2C Seven Segment Display Slave

This is a custom 4 seven segement display I2C slave that I've been using as part of a larger Clock project. I will include sample Master side code in the future. It is of course possible to easily reverse engineer the master side code by closely examining the slave code.

Required Parts include the following:

8 330ohm resistors

2 1.5k ohm pullup resistors

1 16 mHz crystal

4 2.2k ohm resistors

4 S8550 NPN transistors

4 single digit common cathode seven segment displays

1 74HC595N shift register

1 push button

2 22 picofarad capacitors