Features you'd like to see in a electronics calculator

[Jon86]

If someone was to design essentially a command line based calculator similar to Matlab, without so much of the 'programming' aspect, but focused around electronics, what would you like it to be able to do? What would save you time compared to simply using a scientific calculator, while still keeping a relatively simply interface?

The obvious things to me would be complex numbers in both forms, numeric variables, SI prefixes, constants, unit conversions, simplified parallel calculations for LRC circuits, ability to mix and match bases (bin, hex), boolean logic, function definitions, calculus, and some kind of 'objects' to assist with designing and analyzing the parameters of different kinds of filters, amplifiers etc.

I've been thinking about this as more of just a programming exercise, but the more I consider it the more it seems like I'd actually find this somewhat useful myself as kind of a calculation notepad, which lets me keep track of things better than a scientific calculator, and is less clunky/expensive than matlab for simple things.

Hopefully someone will have some thoughts on this, and quite possibly there's something out there that does just this and more.

[rstofer]

wxMaxima (windows GUI) or Maxima (command line) has a lot of capability.  I don't think it will carry units which is regrettable.  It would be nice to see the dimensional analysis.

A lot of the capability you want in a calculator already exists in the HP48GX including a menu of the important electronics equations.  It handles complex numbers in either form, can solve matrix problems and some differential equations as well as plotting the graph of functions.  The Eq Lib is awesome!  For some libraries, the choice of units (CGI versus English) is user selectable.

Some of the newer graphic calculators are even more fully featured.  The HP 50 and HP Prime are candidates and the Prime CAS system is said to be superior.  TI has some high end calculators as well.

I don't know much about the 50 or Prime but I do know that the HP48GX can be programmed to solve just about anything.  I wrote an entire Celestial Navigation Program back in the early '90s and it was just plain fun to program and to use.

[Jon86]

I'll definitely look into wxMaxima, I really like the graphical fraction display that they're showing off in the screenshots too.

Those calculators sound interesting too, I've got a HP49GII but I'm yet to find anything that really helps me electronics-wise, apart from maybe complex numbers and some stats stuff.

I think what I'm envisioning here is something that I (or anyone really) can access at any time, on any device, and be able to create a workspace for calculations, where I don't have to keep writing down numbers and I can make retrospective changes to variables to see what has changed. There are a few things for me that I feel like a standard calculator doesn't do well, and this could be made into a highly portable web and app based interface. Saves me carrying around a calculator bigger than my phone.

[floobydust]

It should automatically give answers in engineering units, like my old Sharp EL-5103s from 1984.
Exponents in answers are held to nano, micro, kilo, mega, giga etc. keeping to threes 10^3n.
I hate getting 3.21E-05 for an answer, when 32.1uA is what I need.

If I have to do an intermediate calculation (a calculation while in the middle of a calculation), it's nice to have multiple memories, and be able to swap, store, or recall. Swap is nice when you want to save a value in memory and recall one, with one button.

[Jon86]

My thoughts exactly, I'd like to be able to interchangably use notation like 5.6E5 and 10.2M then be able to get the answer out in any format/units I want. I know the 'engineering' button on most calculators does that, but it seems like it's missing from everything else.

In terms of recalling and memories, this is my other main issue. If I can define variables and use them later on, this would save me a great deal of pain compared to writing answers down and losing some precision.

I also think it'd be nice to be able to refer to the value given by a previous line, so you don't NEED to define everything you're going to use as a variable.

[EEVblog]

My thoughts exactly, I'd like to be able to interchangably use notation like 5.6E5 and 10.2M then be able to get the answer out in any format/units I want. I know the 'engineering' button on most calculators does that, but it seems like it's missing from everything else.

Decent scientific calcs will also have an Engineering mode (like SCI mode) that will always give results in engineering notation, no need to hit the ENG key.
Sometimes I find that annoying because I expect to see 0.123 or something and it'll change it to 123m

[Jon86]

Hi Dave,

Same for me, my fancy HP graphing calculator does just this, and it's a real ballache to keep switching between different formats in the menu for different kinds of calculations. Again with radians and degrees, it's not easy to use them interchangably without adding in conversion factors.

I feel like any modern device whether it be a phone, computer, laptop, tablet, should be able to do what any scientific calculator does and much more (but without the matlab license and multi-gig application).

[rstofer]

I feel like any modern device whether it be a phone, computer, laptop, tablet, should be able to do what any scientific calculator does and much more (but without the matlab license and multi-gig application).

I can't help with the multi-gig part but GNU Octave is a close clone of MATLAB and it is open source.

It's one thing to have a simple calculator with 4 functions plus a few trig and exponential buttons.  It is an entirely different matter to have to implement solvers for differential equations and such. 

All in, Symbolab.com is easily reached and useful for a host of problems.  It might be possible to rig it up as a backend solver from a web based user interface (for storage, variables, etc).  Or not...

Similarly, Desmos.com does a great job of making graphs from functions.

[nctnico]

I like the SI units. I've been a Casio user for the fast 30 years because HP calculators can't keep up with me punching in numbers.