Does anybody have working example of driving PCF8574A for at89c2051? I'm trying to blink a LED almous about 6 hours with a zero result... :-( SDATA on P1_6, SCLK on P1_7 how to turn on/off LED on PCF A0 ? Thanks...
Have you looked on the Pilips site for examples/Application Notes? Try putting "PCF8574" into your favourite internet search engine. There's an PCF8574 example near the bottom of this page: http://members.home.nl/bzijlstra/software/examples/asmex.htm