Teaching Binary - 4 switches attached to a display - where to start?

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1

Earlier this year I backed a kickstarter campaign to produce a board book to introduce kids to binary. I've found it's a big hit with kids around 6 and they've been looking for other ways to explore binary.

So I had this idea that I could attach 4 switches to a display and they could toggle the switches, and the display would show them the decimal equivalent of their binary creation.

I have some experience coding and I understand basic concepts of electricity. But putting this together will be a learning experience.

Has it been done before? My research has turned up lots of information on 7 segment displays, and binary decoders / BCDs. But either there's something else I need or I'm missing something altogether.

So, what would it take to get this done? I'm not looking for the solution out the gate here. Just an idea as to what types of components I'd need to make this work, how they might line up. High level suggestions to get me moving. Or are there existing similar or related solutions you can point me to?

Thanks. I appreciate any advice or suggestions you have to offer.

Here's the book if you're interested, I just discovered it's still available just not through kickstarter:
A Robot Story {learn to count to ten in binary} by Lisa Seacat DeLuca
http://www.thinkgeek.com/product/1fa4/

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Firstly you are talking about 4 bit binary. The least significant bits is 0 or 1. The next is 0 or 2 then 0 or 4 and finally 0 or 8.

So if you have 1111 that makes 1 + 2 + 4 + 8 which is 15.

You therefore need to display two decimal digits.

You don't need an Arduino to convert binary to decimal but why not...

First thing you need is 4 switches. You could use push buttons or you could use toggle. Your call.

You need to read the inputs. You need to either use pull up or pull down resistors. Pull ups are built in so that would be easy but pressing a button would then ground the pin so when you wanted to detect a "1" you would actually want to look for a "0".

Once you have done that, look at which buttons are pressed, add the binary then out put the decimal.

No problem!

3

Why not add 7 more switches that are connected to a static 7 segment display.
Let them try to turn on the correct switches to make 0 through 9 and maybe some simple alpha characters like the letters A C E F H L etc.