I2c chip(PCF8574) interface to PC by using PIC18F4550

Probably.

Why?

Flash a LED, or read a switch, or read a switch to turn the LED On or Off.

No doubt there are spare pins on the PIC to do that anyway.

So why PCF8574?

So why connect to PC (except to load code into PIC or debug)?

Perhaps you should think of an application and then a way to solve the application, rather than have the devices and make an application.

To connect an 8 bit input/output port to a PC can be done a lot simpler if there was a need.

What do you need to do?

Other than what sounds like either a school project or 'I have found these devices what can I build with them'.

Here is a great project that should help you no end.

Totally incomprehensible. See my sig. below:

-- If you want to post a followup via groups.google.com, ensure you quote enough for the article to make sense. Google is only an interface to Usenet; it's not Usenet itself. Don't assume your readers can, or ever will, see any previous articles. More details at:

-- Posted via a free Usenet account from

Thanks Marra,

I totally understood what you are saying.

Keep up the good work.

donald