Usage of I2c Expander.

Dear all,

I need small clarification on below. In my project ,having there are more digital io being used than no of pins available. I have only one i2c device i.e real time clock. I have heard that using i2c expander we can control digital output.Is it true or false. If it is true can someone share me the how we do that with simple example , i.e accessing the digital ios. Or clarify I2c expander meant for connecting only I2c devices with multiple device address and not for monitoring status digital ios

Yes you can put more than one chip on an I2C bus, in fact you can in theory have 128 of them. You need what is called a port expander chip. There are lots of them to choose from try google.