Finally, A Machine To Organize Resistors!

Perhaps it’s a side-effect of getting older, but it seems like reading the color bands on blue metal-film resistors is harder than it was on the old brown carbon ones. So often the multimeter has to come out to check, but it’s annoying. Thus we rather like [Mike]’s Resistorganizer, which automates the process of keeping track of the components.

At its heart is a fairly simple concept, with the microcontroller reading the value of a resistor by measuring the voltage from a potential divider. The Resistorganizer extends this using an array of analogue multiplexer chips, and is designed to plug into one side of a breadboard with the idea being that each line can have a resistor connected to earth through it. Of course it’s not quite as simple as that, because to maintain a readable range a set of resistors must be switched in and out to form the other half of the divider for different ranges. Thus another multiplexer chip performs that task.

Finally a set of digital multiplexers handles an LED to see which of the many resistors is currently selected through a pair of buttons, and a dot-matrix LCD display delivers the value. We want one already!

37 thoughts on “Finally, A Machine To Organize Resistors!

  1. Why go through all the trouble to read resistors only. Ebay has RLC/semiconductor tester for the cheap. With lcd screen tool. R to the ohm, C down to nano’s with ESR rating, All different semiconductors with pin ID.

    1. I thought that everyone has at least two of those Transistor-Testers at home. The chinese are happily adding features and changing software to detect more stuff.

      Wonderful world we live in. At least partial.

  2. The color codes are getting harder to read, not because of my old age but the quality of the markings. For example we have have 1% resistors in our lab that we bought 20+ years ago that I can read just fine. It’s the new ones from lower quality suppliers that are impossible to read.

    1. I have found the same.
      Cheap resistors from ebay etc are hard to read, but the quality Japanese made resistors I get from Akihabara are really easy.
      The blue is lighter in tone and the paint is a semi-gloss rather than full-gloss of the cheaper ones making for less specular reflections with bright light.

  3. Aw. I thought it was going to be an automatic robot, taking resistors out of a hopper, measuring their values, adding a new label, then sorting them by value somehow.

    You know, like all those Lego bricks sorting robots.

        1. This is what I need, but not limited to resistors. Depopulate a breadboard, drop all the components into a bucket and put it down in front of a robot arm, which dutifully captures and sorts each component and (somehow magically) puts it back in the appropriate location.

          From a time value standpoint it’s more efficient just to toss them all in the trash and keep large batches of new ones on hand.

          on the other hand 97% of breadboarding is 10k, 1k, 330r and a few others :-)

  4. I still have some old 1/2 watt resistors laying around from decades ago. The bands are clearer and easier to read. The colors are brighter. But, the resistors themselves are bigger than their modern counterparts.

  5. In looking through the comments, I think a point that’s being missed is that this thing now lives on my workbench; this is where my used resistors are stored. When I need a specific value of resistor, I now check The Resistorganizer (easily I might add ;) ) to see if the value is there. If not, I grab new from stock.

    Having used it for a week or so now, it works well. My multimeter is right there, but I’m not using it to find (read ‘endlessly hunt for’) the resistors I need anymore.

    Is this ideal? Probably not.
    Is it better than any other solution suggested (or insisted upon)? I think so.

    1. That makes a lot more sense.
      Maybe you also need a pair of encoder knobs, 24-position for E24 resistor values, and one for power of 10, to dial in the resistor you are looking for, so that they can be highlighted?

    2. i wish i had one of all the “tools” i have seen designed with no intention of production or even sharing that i have encountered in old boomers radio shacks, garage corner labs, and garret prototyping niches…(i did get my hands on a videolab finally thnx bill hearn)

  6. So let me get this straight… You aren’t willing to learn the color codes for modern resistors… So instead you handle them… With your fingers… And then trust some little homemade ohmmeter to tell you what the resistance probably is… But it can’t tell you tolerance nor temperature coefficient… And then put them back into a bag or box, once again with your fingers touching the metal leads… For later use? I’ve heard of jumping through hoops to avoid doing something the right way but this takes the cake… And greatly reduces the shelf life of the resistors while you’re at it! Lol

    1. Despite your comment feeling very much like a contrarian’s reflex, you’ve got it about right.

      Except, I know the color code by heart (albeit using a wretchedly deplorable mnemonic); I lack the will to hunt for resistors using that method.

      Tolerances, temperature coefficient, refractory period, total cholesterol, turbidity and leg length detection are all coming in future revisions. Also, it will do all of the above using nothing but 555 timers.

      In the meantime, perhaps I’ll throw another Resistorganizer into the mix and segregate my 1% tolerance resistors on it… and I’ll wear archivist’s gloves when I do.

      We all have our tolerances, mine often disallow me from doing things ‘the right way’ as you say. This little tool / project allows me to spend what mental energy I do have on being productive in prototyping / experimenting.

      Nevertheless, I hadn’t considered the impact of semi-regular handling would have on longevity. So, I genuinely appreciate the feedback.

      1. Your project is cool, I like it. Different ideas and approaches are always good, even if people might end up using another method.

        I could see this being quite useful when maybe there would be another type of organizer, where it’s easier to drop the resistors into without having to plug them in, precisely. It could be extended to other components such as dip chips or transistors etc., and then you could have a catalog and look up the exact position (which breadboard number, which row).

        Either way, it’s a fun project and well made :)

      2. I wouldn’t put the shelf life much past a couple months once you handle them. They will still look shiny but microscopic inspection will show you what I am talking about and that’s when you start having soldering/breadboard issues. I am very sensitive on this topic after working with people who would handle parts and then toss them back in a sealed bag for years, and later others would wonder why the heck they were having continuity or soldering issues with parts pulled from those bags. Low cost resistors always have low cost plating and this low cost stuff is far more sensitive to handling. Aggressive flux can deal with the soldering part unless the leads are quite contaminated but then you just have more mess to clean up.

        It’s easy enough to print out a reference card for the parts of the color bands that are harder to remember (especially when you get into the low tempco MELF parts with dotted lines and such) but for anything 1% tolerance and above the basic color scheme is very easy to remember and in general a DMM is used to verify a resistor, not to measure it, unless you are binning resistors based on where they fall in the tolerance range, and this requires a 4-wire measurement with the lead/contact resistance calibrated out. Obvious exceptions to DMM use are when you are pulling an unknown 20 year old resistor off of a board and you just can’t tell if that brown band used to be a red, etc – A DMM will help you figure that one out quickly… Unless that resistor is so burned that it’s value has drifted considerably, in which case it’s time to start scratching with a little blade under a magnifier to see if you can get through the surface of the paint and guess what that original color was.

        As far as remembering the basic color codes, use this to learn, Bad Beer Rots Our Young Guts But Vodka Goes Well a.k.a. Black Brown Red Orange Yellow Green Blue Violet Gray White a.k.a. 0 1 2 3 4 5 6 7 8 9. When saying the acronym you start counting on your fingers at Beer aka Brown. You’ll learn it after doing it a few dozen times and within weeks you’ll be seeing numbers instead of colors on the resistors.

        1. I feel that everyone (including Jenny in the original writeup) is repeatedly missing the point of this build, that it provides a place to store resistors for breadboard / PCB use that also measures the resistor value and points you at the right one when you want a particular value.
          It has to be better than the normal pile of discarded resistors piled at the side of the breadboard and the “I am sure there was a 2k2 in there”).
          And for the fans of storage bins, even then, you could depopulate the breadboard into the organiser, and then select all that belong in one bin easily (many to one) rather than the one-to-one sorting that is being vehemently advocated here.

  7. I’m way old school (or just way old) but I seldom get out my stock of TH resistors any more. My prototyping usually consists of getting a PCB make and soldering on SMD chips. But sometimes I do use them. A specialized device doesn’t really make sense for me and, since the DMM always sits on my bench, I don’t even have to get it out…

  8. I see absolutely no real-use in this project, but if it makes the builder happy (and even manages to get a Hackaday article) then good for him.

    About the practicality (apart from color blindness or other disabilities that prevent someone from reading color codes)… Putting the resistors in the clips is almost all the work, and you have to get them out again too. Doing them one-by-one or in “batches” does not change anything about that.

    About half a year ago I also sorted several hundred of resistors, collected from old breadboard projects to put them back in their proper place. I did most by color code (it’s a good way to train the colors) and after a while you instantly recognize color combinations.

    But there were also a bunch for which the color code was not easily readable. A good way to do those is to connect one probe of your DMM to tweezers, then you pick up a resistor by one leg wit the tweezers, touch the other leg to the other DMM probe, and then put the resistor in it’s appropriate bin.

    I think about building a small robot arm every once and a while. And with a robot arm this could be done quicker. The idea is that you put a single resistor into some fixture manually, then the robot measures it and puts it in it’s proper bin. It could fold the legs too if that is beneficial.

    1. It’s not color blindness (a misnomer), but a lack of contrast, or choice of bad contrasting colors for variations in color visions. This is not a disability, but a natural variance in color perception.

      But independently of that, nobody wants to decode all those values manually, too time consuming.

    1. How dare you make a fun little useful thing for yourself? Damn, it seems like you really hit a nerve on this one.

      The Hackaday comments always make me think of this:

      But yeah, when you’re working on things like op-amps and trying to get the gain just right, this thing would honestly be amazing. Especially once it’s pre-loaded with a nice range of values.

      I actually just throw resistors away once they come out of the labeled bags from those kits on Amazon. But this could be even more convenient than looking through the bags for the right value.

  9. The trouble with reading resistors, especially the blue 5 band ones, is knowing which direction to read in. The tolerance bar is often the same colour as a “1” (brown), and there is not enough space for a big gap between the resistance value code and the tolerance bar. If they’d go back to 4 bands they’d easily have space for a blank band to make recognising the direction easy.

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