hey, can some1 help me to interface PCF 8574 with 89c51 using I2C bus for interfacing LCD in four but mode please.. its for my final year project it will help me alot if any1 can help me out for the code.. coz im not able 2 get it done.. i dont understand it actually..
"But the above should be absolutely clear if you did search for the excellent descriptions of I2C that are available on the NXP web site"
Not least of which is the PCF8574 Datasheet itself!
This provides a very clear description of how to drive the I2C interface to this device - complete with timing diagrams to illustrate it.
In fact, this is probably one of the best documents to start with for an introduction to I2C - without all the complications of the full specification (which is available for free download from the NXP site)
The PCF8574 is a very well-established, popular device - there must be plenty of examples available for you to look at!