You can read the state of a button using Arduino and a few lines of code. The actual state is shown in the Serial Monitor window as 0 or 1, 0 meaning the button is not pressed and 1 that the button is ...

As you can see in the schematic all three TC74 sensors have their SDA and SCL pins connected in series to pin A4 and A5 on the Arduino board. The two 4.7K pull-up resistors must be used when using I2C ...