Hi Shahzad,

Do you have access to an oscilloscope? Another way of verifying what is going on is to look at SDA and SCL, and compare against the spec. Write a test program that loops on a read or a write, and see what is going on.

If you don't have a scope, it's possible, though painful, to debug such code even with a single LED. You set it at various places within the code to verify that it reached that point. For instance, you could set it at the point where the ack is tested after sending the device address.

Good luck,

Dennis