Building a Calculator

[lukekemp34]

I have been set a a project to make a calculator that will add, subtract, multiply, divide and it must have a 8 digit display. I am very stuck and was wondering if anyone could help with diagrams or websites etc. your help would be much appreicated! cheers

 

[Nigel Goodwin]

I have been set a a project to make a calculator that will add, subtract, multiply, divide and it must have a 8 digit display. I am very stuck and was wondering if anyone could help with diagrams or websites etc. your help would be much appreicated! cheers

You need a micro-controller or micro-processor, expect to spend, most probably, considerably more than the most expensive calculator you can find! - and to spend many days (or weeks?) writing the software.

 

[stevez]

You didn't state any additional requirements but this sounds like a school project. As already stated, a calculator, at least as we think of them today, is quite complex. Now, one might design and build something that will do the calcs but in more crude fashion. As I recall, before digital computers there we analog computers. Didn't they use simpler principles to add, subtract, multiply, divide, etc? You might explore something like this but for the output use a digital voltmeter for the output. If allowed, LEDs could indicate binary - though your description "digital" suggests decimal numerals.

As a simple begining you could 'add' by taking three 1.5 volt cells and put them in series to get the sum - 4.5 volts. To subtract you might reverse one - 3 volts minus 1.5 volts is 1.5 volts. An analog amp with a gain of 5 would serve to multiply the voltage - it will divide if it's less than one.

Just some thoughts. Good luck.

 

[Exo]

If this is a project assigned to you are there any details on how to go about it? (for example you MUST use 74-logic or ...?).
If you are free in your design then i agree with Nigel, get a µC.
A PIC or AVR would be best choices because there's lots of info & free programmer software available (though i'm biased towards the pic )

 

[Someone Electro]

An PIC,LCD and an matrix keypad shod do it

 

[tansis]

Here's an earlier thread on the same subject.

https://www.electro-tech-online.com/threads/microstrip-lines.14105/