I am really new to ardduino and i own a mega that i am messing around with. What i would like to know is what is the upper limit to buttons and switches on a button box, for example is it possible to add 77 switches to a button box and have them all connected to a mega or is that not possible. I am not really sure how it all works at the moment and am just curious as to some numbers that could be possible.
The number is pretty much unlimited- you can use a multiplexer to connect additional switches if you have more switches then inputs on the Mega.
Can you wire them as a matrix?
That would typically take 18 pins.
no idea how to wire them as a matrix as i said im really new at all this and have 0 ideas how to accomplish what i want but thats the fun for me learning how to accomplish what i want. the button box i wish to create will consist of
15 2 way switches
6 3 was switches
18 dials
20 push buttons
10 rotary switches
3 3 way momentary switches
1 12 button keypad
possibly 7 7 segment displays
and various LEDs
i know its pretty ambitious im just curious if its possible.
All that is possible by connecting other hardware to the controller board (your Arduino).
There are several ways it is possible.
But for what YOU can do with Arduino is extended by everything that you learn how to do with one.
Buttons -- are not as simple as would seem but taming 1 can teach much that applies to other input as well. Learning to make a button and blinking led work together is another important lesson that opens up doing many things at the same time coding. With only Arduino and a button (I use a jumper as a button, Uno + jumper = learning kit) you can learn serious techniques to automate using Arduino.
When learning, the simpler the lesson the more easily clear the lesson will be. Trying to learn with a 3 ring circus of a project is how to get and stay confused the longest barring quitting out of frustration and lost money.
If you are new to programming, get into that also on the simple level. Program is how you tell the machine what to do at a very detailed and exacting level. Work your way up, there is a whole set of tutorial examples in your IDE with complete explanations on the Arduino main site. It's not all perfect but you can learn and progress.
The links on this page are most all to articles that will give you grounding and get you started:
When doing your switch tally, and later your schematic diagram, you’ll realise that a single 3-way switch is in fact three contacts (or three 1-way switches).
I suspect your ‘dials’ may be variable resistors (potentiometers), or possibly even rotary encoders.
You need to understand these concepts before getting in too deep, or you may commit yourself to solutions that won’t work.
thanks for the responses i simplified my parts list a little in the interest of time but you are correct some are encoders some are pots. Since i have 0 ideas on how to work with so many items my plan is to start with 1 button and get that working with code etc and make sure it works in the game im building this for and then i will slowly add another button or switch 1 at a time so that i dont get to overwhelmed, should be a cool learning project.
Be sure to check out capacitive touch sensing. There's nothing to wear out.
With a piezo disk you can sense ~about~ how hard a spot is tapped or held.
I have a friend who makes handheld gesture sensors using accelerometers, how many buttons is one of those worth?