AVR-Chat

--- In AVR-Chat@yahoogroups.com, "Richard Cooke" <rcooke@...> wrote:
> I need to read an 8 switch dip switch but I only have 3 inputs left. 
Take a look at the PCF7854 I/O expander (standby current is 10uA).  It 
has an I2C interface and implements 8 I/O lines.  If you already are 
using other I2C devices it won't require any additional I/O lines on 
the AVR.  If you aren't, it only takes 2 I/O lines, preferably SDA and 
SCL.  If those pins are already irretrievably commited, any two I/O 
pins will do if you have the space for the code to bit bang the I2C 
protocol.

Don Kinzer
ZBasic Microcontrollers
http://www.zbasic.net