Im running out of pins in my project and because of that i need some sort of way to minimize the pin usage where there are any possibility. My keypad for that matter uses 7 pins, and i would like if possible to free up some of this in some way.
I tried that, but the outcome is not reliable enough. The output when holding down button 1 as an example could sometimes give me 2 which is not good enough
One way is to use the keypad with it's own dedicated pro mini.
Then send a key press via serial to your project.
Or, pick up Bobuino, it gives you more pins.
Sending the signal to another arduino board COULD be a solution, but i would not say its a good solution. And the Bobuino is out of the question, as this is all going to be used on a Nano later because of size issues.
Use resistors with better variation ratings, like 1%, vs 5% or 10%, then your one-wire solution will give more predictable results.
And pick resistors that provide more separation between the resulting values.
If you don't mind exchanging your keypad for an IR keypad, I am using this method these days with great success.
Only needs one pin, if you don't use the piezo speaker.
It is the BEST way
