Hi Art , hows things on the other side of OZ,

the keyboard will be custom one so can do it any way i like , although it has to include LEDs in the membrane

i need a switch to allow power/ on off and incorporating it into the keypad was the best way to go

I am limited to max of 8 wire connection for the keypad - long story
i am still sorting out the keypad design looks at the moment and trending to a 5 keys including power button , plus 5 leds in the keypad

as such a matrix approach seems the best at the moment

power switch is looking best to be a single button as this can easly control power drectly to regulator enable and the cpu or just the cpu and thus the rest of the pwr cct

this thing is battery powered so like to reduce power to the bare min when not in use ,

but it does have the option to wake up and check messages, advise info every 30min for sec then power down
cheers

Sheldon