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

[cellularmitosis]

Well it is not like we use TH resistors anymore.

I guess I'm not "we"

[cellularmitosis]

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.

and I just look at my desktop wallpaper

[Thor-Arne]

and I just look at my desktop wallpaper

 

[Rigby]

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.

Nope, nope, no, no way, disagree disagree disagree.... well, maybe. 

If you're saying that the time was wasted, I vehemently disagree with that.  Clearly the chap has an interest in software, and this was valuable real-world software design experience that (IMHO) was time well spent.

If you're saying that he should have spent that time on electronics when his at-the-moment interest was in software development, I disagree with you.

If you're saying anything else, I don't really have an opinion yet.

The thing about doing things the hard way is that you can learn a heck of a lot doing it.  The longer route is the longer route but there's more knowledge you don't already possess littered along the longer route, and you won't ever get that knowledge by taking the shorter, easier route.

[rob77]

The thing about doing things the hard way is that you can learn a heck of a lot doing it.  The longer route is the longer route but there's more knowledge you don't already possess littered along the longer route, and you won't ever get that knowledge by taking the shorter, easier route.

 

[AndyC_772]

I guess it depends how you view the time spent on developing this app.

Time spent learning a language, OS, development environment and UI design skills, with a view to re-using these in app development == good commercial skills and time well spent.

Time spent over-engineering a very basic tool that's already been done many times before and which potential users will very quickly grow out of needing at all == misguided, IMHO.

[pickle9000]

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 

Or better yet take a picture of a chip / device and have it come up with a datasheet.

[tautech]

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 

Or better yet take a picture of a chip / device and have it come up with a datasheet.

+1 

[TerraHertz]

Two months to write a smartphone App, to avoid spending one day (maximum) learning a simple color-to-number code.
Having memorized that it will always be with you. No flat batteries, getting lost or stolen, maybe incompatible future versions, etc.

How far we have advanced!   /sarcasm.

Next, write yourself an App to recall the E12 values. Because who has time to memorize that shit, right?

10 12 15 18 22 27 33 39 47 56 68 92

Have to confess I never bothered learning the E24 and higher sequences:
 http://www.logwell.com/tech/components/resistor_values.html

[Marc M.]

I'll toss my hat in the " - just learn it - it's only 10 colors for pete's sake" circle.  If it only applied to TH resistors, I could understand why folks may not really have a need.  But if you pay attention, it is used for far more than resistors.  A very common example is ribbon cable which normally follows the resistor color code for sequence.  This makes it very easy to ID the terminals of a connector if let's say you need to check a voltage on pin 17.  In one of Fran Blanche's videos about the Apollo board that Dave just did a video on, an earlier Gemini board she showed had what appeared to be it's connector pins color coded using the resistor sequence also.  I've run into it in a lot of other places over the years.  At my day job I repair CNC machining centers and I often have to replace components that were hand wired using wire markers to ID wires.  Over time the wires get coated in coolant mist that degrades most types of markings.  I bought paint markers to cover the resistor code and use them to mark each wire in sequence.  It's a very fast way of identifying things when you have a bunch of them.

[SirNick]

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 suspect that technique would be extremely error-prone.  Color-blindness notwithstanding, if you can't tell the color code, your phone's crappy camera will probably fail utterly.  We're not talking about high-contrast barcodes here.

The thing about doing things the hard way is that you can learn a heck of a lot doing it.  The longer route is the longer route but there's more knowledge you don't already possess littered along the longer route, and you won't ever get that knowledge by taking the shorter, easier route.

I regularly reinvent wheels for this reason.  One current project: Write an embedded TCP/IP stack.  Yep, there are plenty of proven options already, and it's not a casual weekend task.  Still, as a network engineer by trade, getting my own code to trade packets with another host is an opportunity to understand the realities of network protocols that is (IMHO) way more beneficial than cramming PDFs to take yet another vendor cert test.  I've also written an open framework media player for much the same reason (to help discover audio file formats and digital audio processing.)

[eneuro]

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 suspect that technique would be extremely error-prone.  Color-blindness notwithstanding, if you can't tell the color code, your phone's crappy camera will probably fail utterly.

It might work, but of course I've no time to play  with crappy phones's apps, but I have one project where OpenCV''s computer vision tools will be used, so as warm up  I'll try autodecode resistors in real time just by pointing cheap USB camera with customized LED light which could help autodetect those colored things on PCB  and mark them with its resistance using artificial neural network instead of human brain
I was involved in a few research computer vision projects in university sometime ago and played with artifical neural networks & genetic alghorithms, so it will be interesting challenge to detect those crapy resistors via image processing, because of course enetring its colors to phone app is nonsense and losing of ones time 

and I just look at my desktop wallpaper

Nice, so let me autodecode them and show & log to file this way. One can verify if colors were well processed by image recognition software 

[bwat]

Still, as a network engineer by trade, getting my own code to trade packets with another host is an opportunity to understand the realities of network protocols that is (IMHO) way more beneficial than cramming PDFs to take yet another vendor cert test.

Yep! Between declarative knowledge (know-that) and procedural knowledge (know-how), I'll take procedural.

Edit: unfunny joke removed.

[Rigby]

I suspect that technique would be extremely error-prone.  Color-blindness notwithstanding, if you can't tell the color code, your phone's crappy camera will probably fail utterly.  We're not talking about high-contrast barcodes here.

OpenCV can probably do it.  Phones usually have an LED of a known color that can shine onto the target, which could make it a lot easier to recognize colors.

I believe someone earlier in the thread linked to such a tool.  Here's something I found, which may or may not be the same as what was posted earlier, I haven't looked.

[David_AVD]

Next, write yourself an App to recall the E12 values. Because who has time to memorize that shit, right?

10 12 15 18 22 27 33 39 47 56 68 92

Have to confess I never bothered learning the E24 and higher sequences:

Deliberate error above to see who's paying attention? 

Off the top of my head the E24 set is: 10 11 12 13 15 16 18 20 22 24 27 30 33 36 39 43 47 51 56 62 68 75 82 91

Beyond that I have no idea...

[eneuro]

I believe someone earlier in the thread linked to such a tool.  Here's something I found, which may or may not be the same as what was posted earlier, I haven't looked.

This link only shows resistors detection on white background and one at the time.
Red line is drawn on this live cam but resistors value should be overlay'ed there aligned with resistor image 

If someone did it, it means it is easy to do it yourself better

[TerraHertz]

Next, write yourself an App to recall the E12 values. Because who has time to memorize that shit, right?

10 12 15 18 22 27 33 39 47 56 68 92

Deliberate error above to see who's paying attention? 

Oops. Ha ha, actually that's a typo not a memory slip. I didn't even read what I'd typed. 82

Anyway, good opportunity to add that knowing the E12 series, and the color codes makes it easier to work out what ambivalent colors must be. Brown, red and orange paints, that are sometimes barely differentiable...  22 vs 33 can be a hard one, except even then you can look at other resistors on the same board that used the same paints, and figure it out. Is there a 12 or 39? Then you know the precise colors for 2 and 3.

I think I learned the color codes when I was about twelve. Brown-Red years old.

[Zbig]

To me, using computer vision software to decode resistor code instead of using an autoranging multimeter or your memory, is like building an android (as in humanoid robot, not a smartphone OS) and making it play a real piano instead of getting a CD/MP3 player (assuming your intent was just to listen to some music).

As for the original poster, judging from his announcement, he's just learned a new useful skill (mobile app development) and it couldn't possibly be a bad thing, no matter how you look at it.

And yes, I'm aware I'm contradicting myself a tiny little bit

[eneuro]

To me, using computer vision software to decode resistor code instead of using an autoranging multimeter or your memory, is like building an ...

... automated image processing system to detect on manufactured PCBs boards defects and verify SMD soldering quaility

Resistors autodetection it is only warm up to more complicated tasks using OpenCV realtime image processing capabilities with artifical neural networks.
It is much more interesting than writting boring simple phone app... to compute resistor value  based on entered color data...
There are other ways today to interface computers than entering data manualy to those small useless phones

[Rigby]

useless phones

"I know you're upset right now, so I'll pretend you didn't say that."

[AndyC_772]

building an android (as in humanoid robot, not a smartphone OS) and making it play a real piano

I wonder if Asimo can do that yet?

[eneuro]

"Modern" "smart" phones are really useless while you can loose your sight looking into its small screens, forget about touching this thing and try to hit small edge 
Also its WWW like interfaces with "patented" not clear visible buttons is a total miss.
But the worst thing is they are very big and I used to carry nothing bigger than waterproof wristwatch 1inch2 (6cm2) optionally with GPS CB radio and automatic heartbeat monitor to be able autocall SOS when in trouble or live danger situations.

There were many those useless samrtphones on MH370 board and no one was found so far or called SOS even using Morse coded radio.. while its.... MEMS accelerometers & gyro might detect unusual G forces like in airbags... so theese devices are useless and only marketing toys so far...

[Zbig]

"Modern" "smart" phones are really useless while you can loose your sight looking into its small screens, forget about touching this thing and try to hit small edge 
Also its WWW like interfaces with "patented" not clear visible buttons is a total miss.
But the worst thing is they are very big and I used to carry nothing bigger than waterproof wristwatch 1inch2 (6cm2) optionally with GPS CB radio and automatic heartbeat monitor to be able autocall SOS when in trouble or live danger situations.

There were many those useless samrtphones on MH370 board and no one was found so far or called SOS even using Morse coded radio.. while its.... MEMS accelerometers & gyro might detect unusual G forces like in airbags... so theese devices are useless and only marketing toys so far...

Uhm, so basically they're too small while being too big, yeaaahhh... I'm not sure what your problem is, but chances are, you're living in some weird parallel universe.

[eneuro]

you're living in some weird parallel universe.

Rather in the world where machines do not tell me what to listen to and what to watch 
We have to be prepared for new challenges and privacy steel attempts while MIT releases open-source software that reveals invisible motion and detail in video:

It is amazing what kind of information can be taken from analysis using software like this for image color frequency changes analysis 

[noah_fakelastnamelike_bob]

this is an amazing idea and i am lazy so i did not read every thing but i have an idea.
this is awesome but you should make this eventually* an add on to a bigger app that does calculations for everything and not just resistors and no i don't mean getting into the thickness of traces but like inductance and other simple* things like that.
and im sure since windows phone use a really simple programing language(or at least well known) someone with your permission could make one with the same name and everything.
 
i currently use electrodude, for this and i also use ohms law caluclator to find resistance(ohms) voltage(volts) current(ampere) and power(watts).
so my idea is just expanding and keep in mind i was to lazy to read every thing else so don't yell at me for repeating some one.
thanks for your time...