Hi all,
Does anyone know where you can buy the EDE1144 keypad encoder ic from in UK - searched all my normal sources & don't seem to be able to locate. Is there a newer/ preferred method for connecting a 4X4 keypad to Arduino (reducing number of I/O ports from 8 to 4).
Many thanks, John
Its not dedicated chip, but a pre-programmed PIC microcontroller - probably harder to source
because of this.
ahhh. that probably explains it then... 
Thanks for that Mark - It looked like a neat solution for reducing I/O required from 8 to 4 - I'll have a look for other solutions.
Regards, John
Why use 4 pins if you can use only 2?
This is probably what you're looking for: Arduino Playground - I2CPortExpanderAndKeypads
PSST:
this chip also send keypress by 5v serial
I bought few of those and I must say that the keypad layout for which they have been designed is laughable and NOT configurable; you have to pull the keys mechanically and re-arrange them if you can; if not then implement translation downstream.
Also the PIC needs external crystal to run and its software based debouncing algorithm some times misses a key press if the keypad happens to produce a bounce which the software ignores as a debounce.
MarkT:
Its not dedicated chip, but a pre-programmed PIC microcontroller - probably harder to source because of this.
Hang on - you could use an ATmega328 to do that!
No crystal.
Or a 168.
May be (much) cheaper.