The Countdown to Maker Faire Bay Area is On!


Iphone Camera Identifies Resistor Values

Computers & Mobile Technology
Iphone Camera Identifies Resistor Values

Speaking from experience, I’ve gone through the madness of sorting hundreds of resistors. Even if you have sharp vision and good color discrimination, it’s a challenging chore. Rich Olson of Nothing Labs coded an Iphone app that allows you to simply take a picture of the resistor, drag bar shaped indicators onto the resistor, and receive the ohm value and tolerance of the resistor.

Since Rich is color blind, this app has particular utility for him, as well as anyone who has trouble seeing those tiny stripes.

[via Hacked Gadgets]

28 thoughts on “Iphone Camera Identifies Resistor Values

  1. Scott McCain says:

    Seriously? I doubt a single real engineer will ever use this app. The time it takes to snap the picture – making sure it matches the template and it’s oriented correctly – I could have just as easily gone to a website (If I didn’t already know my resister values by heart – any decent engineer worth his/her salt should be able to). Just pick an acronym or some sort of mnemonic, e.g. Big boys race our young girls but Violet generally wins.

    1. Michael Colombo says:

      Remember that the maker is color blind, so this has particular utility to him, as well as others who may have trouble making out the stripe colors because of how small they are (this includes myself).

    2. Joshua Hernandez says:

      Using some modern computer-vision techniques, it wouldn’t be too hard to read multiple, scattered resistors, and display the readings in real time, on an iphone.

  2. felix says:

    Wow, a handheld device that can measure resistance? How come no-one thought of that before?


    1. David Dean says:

      That’s usually what I do if I happen to have a meter nearby. I’m not colorblind, but I’m terrible at picking out the colors. Not sure why.

  3. Dree says:

    My mom, my brother, my uncle, and both of my sons are colorblind. Believe me, being colorblind can create a lot of confusion and simple mistakes (and tears when you 7-year-old thinks his orange crayon isn’t working, but it’s because he can’t see it on the green background). I can only imagine finding out your resistors were all mixed up.

    As a kid, I was my dad’s resistor sorter/finder. My brother wasn’t allowed near them. Brown and green looked the same, purple and blue looked the same. Guess who had to resort his sorting?

  4. morgauxo says:

    Not compatible with the iPad2?

  5. Shannon says:

    Awesome idea! And so useful for those who, like the creator, are colorblind.

  6. thisispete (@peteschirmer) says:

    on behalf of color-blind makers everywhere: thank you!

  7. Balentius says:

    Of course, it would be far more useful if you could dynamically resize and move the photo to center the resistor – like, for example, if you have a board with ~10 resistors on it, it would be nice to take one photo, and move it around in the app, rather than trying to line up 10 photos.

    Hopefully a version 2.0 feature?

  8. Cory says:

    When I was an EE student, I had to pre-sort all of my resistors for lab since my colorblindness prevented me from recognizing them by sight and we weren’t necessarily allowed to use a multimeter during labs. Of course, I used a multimeter to do it, but this looks like a more fun way to do it. I’ll be checking it out when I get home and can download it.

  9. greyfade says:

    If this was an Android app, I’d pay for it.

  10. Kent Durvin says:

    I suggest a simple addition of the actual value range based on the tolerance; In the example shown, 19 to 21 Ohms.

  11. Jake of All Trades says:

    Yaaaaay! I’ve been waiting for someone to write this app for years :) Now if only someone will port it to Android…

Comments are closed.

Discuss this article with the rest of the community on our Discord server!

In addition to being an online editor for MAKE Magazine, Michael Colombo works in fabrication, electronics, sound design, music production and performance (Yes. All that.) In the past he has also been a childrens' educator and entertainer, and holds a Masters degree from NYU's Interactive Telecommunications Program.

View more articles by Michael Colombo
Maker Faire Bay Area 2023 30% off early bird ticket sales ends August 31st, 2023!

Escape to an island of imagination + innovation as Maker Faire Bay Area returns for its 15th iteration!

Prices Increase in....