This calculator supports all the basic functions like : NOT,OR,AND,XOR, addition,subtraction,multiplication,division and modulo.
So join me as we are going to enter the world of ones and zeros and play with some LEDs and switches along the way!
Remove these ads by
Signing UpStep 1: Parts List
a soldering iron, some solder wire, a cutter, a needle nosed plier,some wire, wire striper, and some desoldering tools fro fixing mistakes along the way.
The parts for the calculator:
1. 32 LEDs.
2. 8 resistors( The value is determent by the type of LEDs, in my case 91 ohm).
3. 74HC595 shift register.
4. 9 1KOhm resistors.
5. 4 2n4401 transistors.
6. A Perfboard.
7. ATtiny2313.
8. 16 tact switches with 4 pins.
9. some pin headers.
10. A programmer for the micro.
11. 9V battery holder.
12.A slide switch.
13. 7805 voltage regulator
14. 100nF cap
15. 10uF cap











































Visit Our Store »
Go Pro Today »




this article: http://www.kpsec.freeuk.com/components/led.htm#series says it wouldn't work?
also, using 91 ohms and 5v does that mean your led current is 55mA? That seems high to me and using (Vin-Vled)/(Iled) it would mean your led is 0.086V? I'm confused.
But thanks for the great instructable, I'm planning on using these concepts to make a bit led array (as soon as I get my head around it!)
If all of the LEDs are the same the current will divide equally between the 3 LEDs.
But the article is correct generally it's not the best of ideas to use just one resistor but I wanted to save some space and I had the same type of LEDs.
So, you're using blue LEDs and resistors with 91ohm... But my question is what's the source voltage? Doesn't the voltage regulator lower it to 5V ? Therefore you should use 120ohm resistors - am I right?
Thanks
In the upper line in first right LED is the LSB ( Least significant bit ) which is like the first number in a digit. Lets say you work with a normal number of 5623 the number 3 will be like the LSB because if you change it that number the change in the overall value wouldn't change that much.
And the 5 is the MSB ( Most significant bit ) if you change that number the overall value will change dramatically.
So in this calculator the bottom left LED is the MSB one.
Now the way you read the answer is like so : the first 8 LEDs are the lower part of the answer and the bottom line is the upper answer.
To make it a bit clearer lets say we have an answer of 1259, The first line would be "59" and the second line would be "12".
Thanks !
I wish I had more free time on my hands to make something
I used 2 softwares in this project one called "AVR studio" in which I write the program in C and "Khazama AVR programer " that I use to write the program on to the micro itself.
The total cost with the program(which is a 1 time buy) is about 30-40 dollars.
This HEX file will only work for the micro I used so you will need to compile the code for the micro you use.
I wonder why it took 17 days for Instructables to send me an email that this was published? Keep up the good work.
I will fix it as soon a possible.
i want to make this binary calculator with an arduino. Can u help me about the schematic and programming ?
thnks.