
Open Source Calculator Teaches Us about Quality Documentation - sohkamyung
https://hackaday.com/2018/05/18/open-source-calculator-teaches-us-about-quality-documentation/
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stuntkite
I had not heard of this project before and I ordered one after reading this
article and I have to say that everything about their web UI/UX experience is
world class. Possibly some of the best I've ever seen. Their simulator[1] is
accurate AND responsive to even weird mobile form factors.

The web site is snappy and has zero cruft. I feel like their design was
inspired by or comes from the same school as Teenage Engineering, who made the
OP-1 synthesizer.

These cats are doing amazing work. This is a masterpiece.

[1] [https://www.numworks.com/simulator/](https://www.numworks.com/simulator/)

[2]
[https://www.teenageengineering.com/products/op-1](https://www.teenageengineering.com/products/op-1)

~~~
bscphil
Also an excellent example of how a site can (and should) be functional without
javascript enabled, incidentally.

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calcifer
For those without noscript etc. this [1] is how it looks without JS.
Absolutely amazing.

[1] [https://i.imgur.com/gTXPXrx.png](https://i.imgur.com/gTXPXrx.png)

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ChuckMcM
I've got two of these and I love them. One if for development and has the 10
pin debug connector soldered in, the other is in its "standard" form for the
most part except that it exfiltrates the UART because part of my plan is a
make it the visual output of an VNA.

The only complaint I have (and its minor) is that the contrast on the case is
poor. A black case with white, light blue, and orange labels would have been
stellar, with the white case things fade into the background.

~~~
techdragon
This is actually one of the biggest reasons I’ve not bought one already. The
colour selection is deeply flawed in my opinion. I say opinion but it’s my
opinion based on years of paying attention to user experience and ergonomics.
It has a low contrast and low contrast is bad on items intended for swift and
decisive use. Sure, too high of a contrast will be bad, but that’s partly
dependent on font and other aspects of the design as to when it becomes “too
high contrast”, regardless of that, this colour scheme is far too low
contrast.

~~~
jiveturkey
Since nothing but the logo is printed on the case (the button membrane has all
the symbols directly printed on it), unlike say the swiss micros, you could
very, very easily take it apart and spray it another color.

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antirez
Played a bit with the online simulator and immediately ordered one for my son
(high school). Great UI, I could immediately print a function, realize that it
was showing sin() in degrees and immediately found how to change it in radians
and to cap the graph to x between -5 and 5. Trivial things but usually I don't
find my way easily in a calculator that I do not know because most UIs suck.

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dm319
I very much like the idea of this calculator, particularly since it has a
python implementation. However, there are a couple of caveats - it uses binary
arithmetic, though since release it seems they've improved the accuracy, and
also I'm not sure how free this license is[1]. For something that isn't open-
source, but uses RPN and has quad-precision binary-encoded decimal precision
the DM42 looks really nice[2].

[1]
[https://github.com/numworks/epsilon/blob/master/LICENSE](https://github.com/numworks/epsilon/blob/master/LICENSE)
[2]
[https://www.swissmicros.com/dm42.php](https://www.swissmicros.com/dm42.php)

~~~
PetitPrince
>I'm not sure how free this license is.

There is an ongoing discussion about what license to use for what part of the
project, and what is the rational behind such and such choice. See this Github
issue:
[https://github.com/numworks/epsilon/issues/38](https://github.com/numworks/epsilon/issues/38)

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aw3c2
If anyone from the project reads this, your website is unreadable due to
abysmal contrast. Please see [https://www.w3.org/TR/UNDERSTANDING-
WCAG20/visual-audio-cont...](https://www.w3.org/TR/UNDERSTANDING-
WCAG20/visual-audio-contrast-contrast.html)

~~~
sriram_malhar
+1. The site is beautiful, but isn't good for older eyes. Too many sites seem
to do this nowadays. I applaud them for their creativity, but they need an
older person to test-drive it.

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bobcallme
How is this "Open Source"[1] when everything is licensed CC BY-NC-ND? What was
the point of releasing anything if changes can't be made or shared? One might
as well get a TI-84 since there are FOSS firmware replacements [2] and it
would be much more free than this.

I would have bought one of these if the license was not so restrictive.

[1] [https://opensource.org/osd-annotated](https://opensource.org/osd-
annotated)

[2] Knight OS [http://www.knightos.org/](http://www.knightos.org/)

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siproprio
It looks like an underpowered copy of the HP Prime.

Why should I own one, because it is open source?

~~~
zeth___
Who owns a calculator outside of schools?

Everything can be done better and faster in a cas on a laptop.

~~~
wtallis
> Everything can be done better and faster in a cas on a laptop.

Everything except actually typing in the problem. A good specialized keyboard
and input method (RPN) will always beat QWERTY, especially one that doesn't
even have a number pad.

~~~
zeth___
Unless you need to do real calculations, in which case qwerty beats the pants
off RPN because you are just programming.

Calculators are a relic from a bygone era, kept in use only by regulations and
a captured market.

~~~
saagarjha
> Calculators are a relic from a bygone era, kept in use only by regulations
> and a captured market.

Uh, no. I often find myself picking up a calculator rather than opening up
Mathematica to do a lot of calculations.

~~~
zeth___
Might I suggest Jupiter notebooks?

They are like mathematica, but don't suck.

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haZard_OS
I hate to be a naysayer here (because I actually like the idea of this
calculator) but I use R for virtually every mathematical and statistical
problem I encounter. It's always open on my computer while I'm working and I'm
comfortable enough with the program that most of the syntax requires little
thought on my part.

If I'm in the field and need to perform some calculations, I either use my
phone (for simple calculations) or my $17 Casio statistics calculator.

As a risk assessor and environmental scientist, I have NEVER needed anything
more than these.

~~~
newen
I have a TI-89 emulator in my android phone. I use it all the time from simple
calculations to graphing. I think I might have used the calculus functions a
couple of times. Anyway, it's really convenient and now I wouldn't even think
about carrying around another device that only does what a calculator does.

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wycy
Would this be a good calculator to get for actual engineering work, or is it
too limited by its testing restrictions? If not, what is a good engineering
calculator these days?

~~~
wtallis
This calculator is made for high school math, not science. Its main concession
to exam rules is a special mode that you don't have to engage. Outside of that
mode, the big feature that's still missing is a Computer Algebra System.

But what's usually not even on people's radar is whether the calculator can
handle units. The line of HP calculators that ended with the HP 50g had the
most useful system I've seen for computation on quantities with units. It
serves both as a type checking safety feature and provides automatic
conversion. TI's top graphing calculators have had similar functionality since
at least the TI-89/92 generation, but (as usual) without a good user interface
to make it worth using. The NumWorks calculator does not appear to have any
capability for unit conversions, let alone carrying units throughout
calculations.

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saagarjha
Looks great, but there are a couple things that I think they could work on:

> $99.99

This is in-line with, or slightly above, other players in the market (e.g. TI,
Casio). I'd love to see someone challenge them in this space with something
that's like $25. I can get a cheap $10 scientific calculator that does 60% of
the same things for $10, so it really seems like there is a spot here for a
lower price point. Especially since the hardware is so "old".

> 20+ hours of use on a single charge

A couple hundred hours would be nice. The benefit of a normal calculator is
that it works without charging really being a thing that most people have to
worry about.

~~~
blattimwind
> A couple hundred hours would be nice. The benefit of a normal calculator is
> that it works without charging really being a thing that most people have to
> worry about.

This is almost certainly due to using what looks like either a transmissive
LCD or an OLED display, which require a lot of power.

~~~
saagarjha
Yeah, I'd love to see something like an E-ink display that holds its charge
much longer.

~~~
froindt
How would an E-ink display work for a calculator? I haven't used them for more
than about 20 minutes in my life, but as long as there isn't a lot of lag
while typing, it seems line it'd be a good choice.

Much of the time a calculator is glanced at while doing math on paper or
sitting idle while waiting for the next input. A 0-energy display would be
ideal for this. It'd be interesting to see a breakdown of energy and energy
consumption by part on a calculator.

~~~
blattimwind
A solar-powered scientific calculator consumes less than one mW.

