Well, thanks for the explanations. This clears up few things for me.
GARTHWILSON wrote:
It's to be able to use PB7 for more things, in this case for a beeper and for turning I²C power on and off. As the third bullet point below the diagram says, you can use PB7 for something like a piezoelectric beeper
This is where I missed it. I was searching for a beeper in the circuit and wondering what is the function of a beeper in I2C circuit.
I have one more question here. Why do we want to control the power to I2C devices through PB7? Why not directly connect them to positive supply? Apart from the provision to plug and play, is there any other advantages?
And the LED given in the circuit shows whether the I2C devices are powered at the moment?
Or I assume it is to save power? Power the I2C devices, get the data and power them off kind of circuit?
Thanks