resistr app - A beautiful, easy to use, resistor color code calculator

[tszaboo]

People don't just memorize this?

Well it is not like we use TH resistors anymore. But to be fair, last week I worked with some melf resistors, those have stripe also.

[rob77]

People don't just memorize this?

Well it is not like we use TH resistors anymore. But to be fair, last week I worked with some melf resistors, those have stripe also.

actually i'm using THT components quite often during proof of concept on a breadboard and prototyping on a protoboard, and i think there are more of us hobbyists doing it that way i don't like simulations - i rather "eye-ball" the values and adjust during proof-of-concept phase on a breadboard. for many ICs i have to make adapter boards (nonexistent or unavailable in DIP), but luckilly resistors and capacitors are still available and will be available in THT for a long time yet. therefore the ability of reading the color stripes directly is still a desirable skill among us hobbyists

[MisterDiodes]

You probably don't need an app for resistor color codes (even if you still use TH parts)...Just resort to some mnemonic poetry to help you remember the color order.

One of the cleaner versions I learned is:  Bad Booze Rots Our Young Guts But Vodka Goes Well.

It goes downhill from there into various versions that can't be used in a public forum. 

[MisterDiodes]

Sheesh - I should have just looked here:

http://en.wikipedia.org/wiki/List_of_electronic_color_code_mnemonics

[rs20]

My concern would be that anyone using this app is actually insulated from the (relative) elegance and memorability of the system. Making little helper devices that hide away little difficulties encourages fear and apprehension about what's really going on. Does this attract people to electronic engineering, or does it attract people to Resistr while making them fearful of electronic engineering?

"OK, I'm going to try to memorise this. So if the third band is orange, you put the decimal point after the second band... and the answer is in kiloohms... but only if this is a 3-band resistor. If it's 4-bands, you put the decimal point after the third..."

No. Orange means 3. Always. In this case, 3 zeros. Done.

[Dagon]

You guys have some complicated systems. Personally I have to use my limited brain power for other things. If I have an unknown resistor I just stick a multmeter across it.

actually it's pretty easy to learn "reading" the resistor values directly from color code. i don't even think about the colors i see - i "read" the value directly. it's like learning an extremely simple language

Matrix style "I don't even see the code", I like it 

[rob77]

You guys have some complicated systems. Personally I have to use my limited brain power for other things. If I have an unknown resistor I just stick a multmeter across it.

actually it's pretty easy to learn "reading" the resistor values directly from color code. i don't even think about the colors i see - i "read" the value directly. it's like learning an extremely simple language

Matrix style "I don't even see the code", I like it 

actually it's pretty natural to the human brain it's very similar to learning Morse code - you don't listen to dots and dashes , you listen to letters and numbers - your brain does the translation

[David_AVD]

Reading resistor colour codes is an easily learnt skill for people with normal colour vision.  I learnt when I was about 10 years old.  It's just not that hard to do.

Relying on a meter can land you in trouble when repairing equipment.  Being able to scan a PCB for low value resistors (that are more likely to be damaged) can really speed up the diagnostic process.

Reading the values becomes second nature and you don't really have to think about it.  You just see the values almost instantly.

[Neganur]

How about you make your app help learn the colour code, what will those poor students do when their phones are out of battery.
I would think that this is probably one of the most beneficial things to learn in a proper way instead of just learning some rhyme by heart (i.e. Big boys race our young girls ...)

I forgot the exact words I used when I learned the numbers many years ago but it was something like this:

a black hole holds zero
one brown chair
two red lips
three orange oranges
four yellow lemons
five green leaves
six blue walls
seven purple violets 
eight grey octopus arms
nine white mice

translated from Danish, so that's why it's orange oranges (orange appelsiner) but maybe you get the idea and can find better native English mnemonic.

[echen1024]

I use Agilent Elec. handbook which ahs resistor colors, capacitor codes, logic simulation, AD conversion simulator, and a resistive divider solver. I find myself using the cap codes frequently, as I have memorized resistor colors and the resistive divider.

[Rufus]

Reading resistor colour codes is an easily learnt skill for people with normal colour vision.  I learnt when I was about 10 years old.  It's just not that hard to do.

Memorizing resistors in the E6 range gives you 9 of 10 colors.

[Pack34]

Why not just use a meter? I rarely use through hole resistors, but when I do I just grab them out of their bin/bag, verify with a meter and install.

[SirNick]

I confess that I haven't memorized a lot of the stuff that I should to be a "serious" hobbyist.   I probably would've given in and practiced the color codes if I could reliably tell all the colors apart, but  I mostly use those mini, 1%, 1/4W TH resistors.  The tiny and sometimes badly printed markings on a blue background can make red, orange, and brown look almost identical.  If I haven't just pulled it from organized trays of new parts, I'll almost always meter it anyway, just to be sure.  Not to mention the number of times I couldn't tell if the brown stripe was supposed to mean "1xxx ohms" or "1% tolerance".

As far as app-based references, I use Resistor Calculator and Circuit Playground.  Resistor Calculator is lightweight and loads fast, while CP has a lot of other handy features (calculators and pinout references) so I'll use that instead if I have other things to look up.  I would not bother to download this one though.

OP -- here are the reasons why I would pass over your app in the App Store.  This is only meant to be constructive criticism:

1) It doesn't do enough to be useful.  If I'm going to take the time (...) to pull out my phone and load an app, it should at least cover all the resistor types I use.  Sure, I have some of 3-band resistors, but not many.  Most of them are four bands.

2) If I'm going to bother with an app, color codes needs to be but one of its handful of useful purposes.  Other handy things:  Series-parallel calculators, cap codes (104, etc., preferably with the alpha codes as well), temp-co (C0G, X7R) reference, etc.  Also, consider having a value-to-color mode as well.

3) Convenience is the number one concern.  Balance features and looks with load time.  If it's a bloated beast of an app, I'll download something faster instead.  I care a lot less about it being beautiful, and a lot more about it being fast and easy to navigate.  If I'm using the app, I'm probably trying to verify a part -- not in the mood to fawn over UI aesthetic.  You're making the mistake of thinking your pride distinguishes your product.  Your users will not share your priorities.  Keep that in mind.  It's a common trap for engineers of any persuasion, from PCB design to code to architecture.

[andyturk]

[...] you get the idea and can find better native English mnemonic.

Bad Boys Rape Our Young Girls But Violet Gives Willingly.

Learned that in the Boy Scouts(tm).
 

[N2IXK]

Bad Beer Rots Our Young Guts, But Vodka Goes Well.....

[David_AVD]

I simply learned the colour sequence.  No mnemonics required.   

[eneuro]

Relying on a meter can land you in trouble when repairing equipment. 

Relaying on color resitor codes when repairing PCBs  can sometimes lead to huge mistakes if it was overheated and its oryginal colors... changed while it was close to explode 

Impedance meter with <0.6V test voltage in pulse can be more usefull than any touching those small "smart" phones screens.
These devices are useless and I prefere normal old classic phone with call/cancel button.
If you know where to find smalest one @ classic hand clock size without any android or worse window$ let me know 

[Rigby]

People don't just memorize this?

Agreed.  Black, Brown, the rainbow = 0, 1, 2-9.   Not sure what's so hard about it.

Well done on the app, though.  Seriously. 

edit: this reminds me of the time I was in HS, and our brand new LaserJet III arrived.  It had a HPL reference booklet that came with it.  I fiddled with that for a while and was printing all kinds of neat stuff, using up all the toner & getting in trouble.

I decided that it would be easier to write a .bat file to print a cheat sheet small enough to tape to my thumbnail than it would be to actually memorize the material for one of my classes, but our DOS environment was such that I couldn't save the .bat file while I was working on it.  No floppies, no hard drives, and for some reason that I can't remember, I was unable to edit the program after I entered it.  I had to reenter the entire thing each iteration.

Well I wound up re-typing the cheat sheet so many times that I memorized everything on it before I had debugged the .bat file fully. 

That's what this app feels like, to me.  I learned a hell of a lot about HPL and DOS escape sequences, AND I learned all the stuff I could fit onto that tiny bit of paper (which was a lot.)

[bwat]

Any mnemonic is only of use to us who don't have to read the code every day. The colours are no different to the digits. If you can use digits in scientific notation without mnemonics then your brain could do the same with colours. I have no problem believing there's people reading this who don't even "think" of the colours they just see the numbers.

Technically "10e2" and "Brown Black Red" are both representations of the same number. If you think "10e2" or "1000" are numbers then you're so used to using the digits that you've confused the number and its representation. There's no difference between them, they're both learned representations.

 

[SirNick]

... if you use them every day.  Alternatively, if you've used them for 30 years.  There are many of us who build things on the weekends, and may need to identify a few resistors by color code maaaaaybe once a month on average.  As SMD gets more accessible, then it's only useful when prototyping on breadboard.

Add to that the plethora of things the hobbyist will need (want) to know:  C, fuse settings, crystal frequencies, CLI commands, pinouts, part numbers, so on and so forth.

That's what's "so hard about it."    Not actually hard, just not something that's constantly on the forefront for some folks.

[grumpydoc]

You do have to be careful these days what mnemonics you teach - otherwise you could land in hot water

I confess to having learnt that particular rhyme when I learnt the colour code, albeit with a slightly more pejorative word for the 2nd "B".

I'll stick to Black Beetles Running On Your Garden Bring Very Good Weather, for now,.... maybe 

The difficulty I have these days is that red, orange and brown seem to have become  indistinguishable.

[free_electron]

here's a thought : why not make a simply app that uses the camera to snap a picture and tells you what value the damn thing is ?

i am color blind. i have no clue if i am looking at a 1k1, a1k2 or a 1k5 resistor.
camera's are not color blind.

anyway the point is moot. i only use surface mounted parts 

[grumpydoc]

here's a thought : why not make a simply app that uses the camera to snap a picture and tells you what value the damn thing is ?

Somebody already did - there was a link earlier in the thread.

Being colour blind is a perfectly good excuse for not bothering but it's not exactly hard to learn and use otherwise.

[ampdoctor]

Bad Boys Rape Our Young Girls But Violet Gives Willingly.

Learned that in the Boy Scouts(tm).
 

As coarse as that is, it's still a sanitized version of the original which is politically incorrect and racist beyond words. They changed the first word so I'll let you figure it out on your own.

But yeah, once you've heard that mnemonic you won't easily forget it, and within a very short period of time it becomes automatic and you won't need it or a calculator. As previous posters have already pointed out, color codes are becoming less relevant by the day.

[cellularmitosis]

I'm afraid I think your two months' worth of free time would have been much better spent learning, say, how to use an FPGA or an ARM based microcontroller if you can't already.

It depends upon what his goals are.  Having a self-developed cross-platform app which has made it into Apple's App Store is enough of a resume to guarantee a position at an app development shop.  With sufficient hard work, he is then just 5 years away from making $100k+.  Certainly not a waste of time if that is his goal.