Hi,
on a new project I use Peter Danneggers I2C sources he offers on his
website but couldn´t get them running so far. Since the timing on the I2C bus isn´t that critical and all my ´51 projects run at 24 MHz I replaced his delay routines/macro with the necessary NOPS to produce
at least 5 µSecs delays, the hardware side should be allright with 2*10k
resistors connected to Vdd and the PCF8574P tied to address:
0100111 with the 3 adress pins to Vdd. This I also corrected in Peters
main programm where it seems like he uses the 8574A version.
No other I2C devices are connected so far.
On my board the 8574 reacts once to a write command, but instead of writing a 0 to a single pin while letting the others high it brings all I/O pins low. Any idea ?
Did anyone else work with Peters I2C code in the original version ?

Thanks very much in advance,
Karsten