Il 04-Mar-98, Thomas M. Alldread scrisse:



>> agree, but don't think you can use the terminology I/O expander
>> this application. Its more like O-only expander, since this
>> only allows you more output pins, but not more input pins.  If
>> really want to have a true I/O expander, you should consider
>> like the Phillips Remote 8-bit I/O expander for I 2 C-bus,
>> the PCF8574 IC.

>        You may wish to consider the 74HC299 Universal shift register
> which according to the specsheet should provide bidrectional I/O.

It requires two more signals to select the operation mode..

a better solution would be taking a 16C54 (or even a 52), providing
it with I2C slave routines for a full i2c 10pin i/o expansion...
it should work...


--

   - *Alex* -

  http://freepage.logicom.it/azummo/