Help me please...

in two arduino I2C communication, how to give the identity of each sensor? I wear 4 pieces analog sensors. I am grateful if anyone help me. thank you

Every thing you need for I2C comms is here:-

http://gammon.com.au/i2c

Look for the code for the I2C scanner.

G

The master knows which device it asked for data from. Why is it necessary for the slave to identify itself? Even if it is, why is that even remotely hard?