Solderless Noise-o-Tron Kit Makes Noise At Chicago Makerfaire


Anyone who’s manned a hackerspace booth at an event knows how difficult it can be to describe to people what a hackerspace is. No matter what words you use to describe it, nothing really seems to do it justice. You simply can’t use words to make someone feel that sense of accomplishment and fun that you get when you learn something new and build something that actually works.

[Derek] had this same problem and decided to do something about it. He realized that in order to really share the experience of a hackerspace, he would have to bring a piece of the hackerspace to the people.  That meant getting people to build something simple, but fun. [Derek’s] design had to be easy enough for anyone to put together, and inexpensive enough that it can be produced in moderate quantities without breaking the bank.

[Derek] ended up building a simple “optical theremin”. The heart of this simple circuit is an ATTiny45. Arduino libraries have already been ported to this chip, so all [Derek] had to do was write a few simple lines of code and he was up and running. The chip is connected to a photocell so the pitch will vary with the amount of light that reaches the cell. The user can then change the pitch by moving their hand closer or further away, achieving a similar effect to a theremin.

[Derek] designed a simple “pcb” out of acrylic, with laser cut holes for all of the components. If you don’t have access to a laser cutter to cut the acrylic sheets, you could always build your own. The electronic components are placed into the holes and the leads are simply twisted together. This allows even an inexperienced builder to complete the project in just five to ten minutes with no complicated tools. The end result of his hard work was a crowded booth at a lot of happy new makers. All of [Derek’s] plans are available on github, and he hopes his project will find use at Makerfaires and hackerspace events all over the world.

37 thoughts on “Solderless Noise-o-Tron Kit Makes Noise At Chicago Makerfaire

  1. Respect for the initiative, but c’mon does anyone knows what astable multivibrator is anymore ?

    MCs are slapped onto anything and everything and a simple circuits are forgotten.
    Those simple circuits actually teaches you about electronics more than a complete semester.

    I do appreciate MCs for the things you can do with them without adding complexity, but they’re moving people away from physics of electronic circuits.

    1. Folks can whine about the ‘good old days’ of analog electronics until they’re blue in the face – fact of the matter is that using a 555 would require a more complex circuit that would have been prohibitively difficult to assemble in this fashion and more difficult to explain to complete newcomers to electronics.

      If you still think a 555 would have been better, please fork the project and lay out a board – I’ll be happy to bring it to the next Faire.

      1. Derek,
        Please don’t take my comment personally. As I’ve said, I have nothing against MCs, they’re great and welcome to produce an awesome things that would normally take months to construct from sole components.

        When I’ve mentioned astable multivibrator, I was talking about two transistors four resistors and two caps – the circuit that is a bare minimum of showing three basic construction components of all electronics influencing each other, creating working circuit that is yet easy to understand from it’s schematic.

        When I was starting with electronics back in days, 555 represented as a sole block was frightening to me because I couldn’t understand how and why it works.
        The only thing I could do with it is to “copy-paste” it from the schematic and wonder to it – fiddling with external components attached to it I could produce variations, but I wouldn’t know why.
        The same goes for MCs and today’s newcomers – they just see it work, but they can’t yet understand why.

      2. I can only see maybe 2 extra components (resistor, capacitor) to make the 555 work. Utilising a uC for this in a way keep the most basic builders out unless they buy the kit from him or have experience with burning code to uCs…

        1. 1) I am not currently, and have no plans in the future for, selling kits. I gave away a hundred of these at maker faire, and I’ll likely do as many or more at the next event I take them to.

          2) The ‘point’ of this project isn’t for novices to seek it out and build it on their own. It’s intended for self-proclaimed Makers from hackerspaces or educational groups to present to those who might have an interest in electronics.

          3) Like I’ve said elsewhere – if you can design one based on a 555 that remains easy to assemble, submit a pull request. I will gladly take it with me next time I take these somewhere and offer it as a ‘level 2’ kit.

    1. It might be cheaper, but only slightly. The ATTINY45 costs about 55 eurocents in quantities of 25 and more, and while the TLC555 itself might be cheaper at about 35 eurocents (both at Farnell, excluding VAT), it does require a few more external components (timing resistors and capacitors), making the circuit more difficult to build, and a regular NE555 won’t run on a 3V battery. Also, with the ATTINY you can get pretty much any mapping from light intensity to frequency and volume that you’d like, and you can do stuff like automatically adjusting for the ambient light level.

      1. This also gets that ATtiny45 out into the world, hopefully to be reused in a different project. That’s not saying that a 555 couldn’t be reused, but I think the barriers to entry for Arduino-compatible chips are lower than for 555-based circuits just because of the volume of Arduino support groups/tutorials/examples out there.

      2. Yeah, I was about to mention also the fact of the 3V battery. Another thing is that the number of components is smaller and the circuit is more flexible. Sorry to say but I have a feeling that analog circuits are going the way of the vacuum tube…

    2. The current circuit has four components and is skirting the edge of maximum complexity for this construction technique. One based on the 555 would not be buildable.

      1. Why? A 555 is not some complex behemoth unless you’re looking for exact timings (oh noes, maths!). An extra resistor and cap would be all that’s needed. And for something like a theramin, you don’t care about tolerances.

  2. This is great, but I would charge people $10 for the intro course and give them the tiny Picaxe kit as well and use the picaxe processor for this kit. that way they can build something and take home the full picaxe kit ($3.95 retail) so they can continue exploring.

    Class #2 can be soldering up your picaxe kit and intro. $10 is pretty much chump change and it will cover all costs for the presenter.

        1. Yep – finding a better way to do that is high on my list of priorities for this project. I’d like to design a laser-cut jig that allows someone to just drop the IC in, drop the extensions in, and solder away. There may be a better solution that hasn’t yet occurred to me.

  3. Maybe it’s the coffee talking but this gives me a lot of thoughts. I feel like this article brings up a lot of issues at the core of the maker/ hacker movement.

    -What is a hackerspace? Maybe it’s hard to explain because we don’t actually know ourselves. I’ve seen hackerspaces that are little more than a private club of friends who share tools, and I’ve seen hackerspaces who see education and outreach as their primary mission, and lots of things in between.

    -What counts as ‘easy?’ Many of us want to make getting started in fields like electronics easier, but we don’t agree on what this means. If something is not difficult, but requires access to a rare tool like a laser cutter or 3d printer can it still be said to be easy?

    -What is the role of expertise? As hackers and makers we highly value expertise of any kind. Yet, as we strive to make things ‘easier’ we undercut to some extent the value of expertise– For example, we’ve made microcontrollers ‘easy’ to program, which undercuts the expertise of those who know how to work without them. We get in a lot of arguments about the value of this expertise and the value of those who do without it.

    (Not saying anything here that everyone doesn’t already know probably. The coffee just made me want to write it down!)

    1. #1- Hackerspaces are unique like snowflakes which is what I like most about them

      #2- Showing something cool made on a laser printer or 3d printer sparks curiosity that may grow into full-blown hardware hacking some day. If you did want to do this exact thing (give away kits to kids) I will be simple to find a local hackerspace that would etch all the acrylic for you just to help out in a small way.

      #3- I think making things easier becomes a “gateway drug” for electronics. There will be a small percentage that wants to dig deeper into the underlying principles.

      1. The reason I like making things easier is to just lower the barrier to entry. A kid putting together this kit might not learn a whole lot about electronics, but it might get them excited enough to look into electronics further. I think there will always be people out there who are really passionate about this stuff, and they will be the experts. The ease of entry into electronics just allows more people to build cool stuff, quickly.

    1. The last time I tried to take a cell phone video, the noise actually didn’t register. It’s fairly quiet, so I’d probably need to break out actual recording gear to do it justice.

  4. Just like anything else, if a person is slightly interested in a hobby, a job, or a certain subject, and they are given the opportunity to sample a part of that interest in a positive, physical and/or mental way, they are more likely to either jump in with both feet, research it further, or decide they are really not that interested in it. Most hobbies have a general description, yet have a lot of different aspects or sub-hobbies to focus on.

    If electronics is an interest, perhaps this general subject could of more interest to the person by learning the basics of electronics, then they might become interested in radio communications, then ham radio, then hf or vhf communications, digital communications, then computers for digital radio communications, then programming for digital communications, and along the way become interested in emergency communications support for their community during a disaster, etcetera.

    The point is, get somebody’s very basic interest piqued so they explore and study, and experiment further. They will, in time, figure out the route they want to take. It really doesn’t matter how it is done, just that it has a very positive, confidence building aspect in the way it’s presented. Bickering over whether an ATTiny45, or PLC555, or any other circuit is used to do it is just petty and very non-productive. In fact, of those people that might be interested reading these posts and comments could very well have turned away from electronics, DIY, and this site or ones like it, never to return.
    There is room enough to share ideas without bickering about the best way to do something, but rather discuss, suggest and share ideas for improvement on a particular device, procedure, line of programming, or whatever it happens to be, instead of drawing lines in the sand daring somebody to cross it and defend with a “My way has always worked and so it should be done that way” attitude.

    Remember, there is always room for improvement in everything. What works best for some doesn’t work best for others. Not everybody sees the same things the same way, especially based on the different levels of experience and expertise. Those with more experience and knowledge in a subject should help teach and tutor those with less, and do it with patience. Some learn quicker than others.

    ATTiny45 or PLC555? Who cares? If it works as a good recruiting tool, use it; improve it; tweak it so it works better.

  5. Maybe talking with people, interacting with them, and letting them put together something that works is way more important than the electronic components. We can’t place a value on what Derek did for hackerspace and for the young minds that participated in his booth. I’m in awe of that.


    My view was always that people shouldn’t use arduinos for simple tasks that can be completed by some discrete logic chip or a 555 timer. I have even resorted to believing people that do this is stupid and have even said it indirectly once or twice. The truth is that I am the one in the wrong and there are many other people thinking the same thing and hopefully with the aid of this post I will be able to convince at least a person or two otherwise.

    Why do I believe that I was wrong? Because the arduino is just a tool nothing more nothing less. If someone wants to use a arduino or an raspberry pi , let them. Logic gates is just a tool , if someone wants to use , let them. Analogue circuits is just a tool , if someone wants to use , let them. Why do I need to know how an astable transistor network works if I want to blink an LED? The point remains is that we humans make tools for our selves and continually improve them. That is all an arduino is. the same goes for an raspberry pi. Sure its not the most cost effective way to do things , or is it? How many tasks can a micro controller complete versus what a 555 can do? Each iteration of electronics adds another layer of abstraction. This school of thought that the person does not know enough need to stop. The person knows enough if the project was a success or something new was learned along the way.

    The only counter argument I can think of is in production scenarios. Where the cost out weighs the difficulty of using the correct technology. If you are a novice trying to mass produce something i would rather suggest you ask for an second opinion and then continue with your product.

    At the end of the day the price to obtain knowledge is almost always justifiable , else we wouldn’t have gone to the moon and would not have built the large hadron collider. Also if the person really are interested in how electronics works they would learn it when they want to.

    1. I very much agree with what you say here. How you solve a problem really depends on the goals. If you are a professional designing a circuit your goal might be to achieve maximum efficiency at minimal cost. In this case, the goal was “get people interested in making things, inexpensively”. I think Derek hit the nail on the head with this project. He could have accomplished this goal in many different ways. He used the tools and knowledge he already had to achieve his goal, rather than trying to find the absolute “perfect” or “pure” way to do it.

  7. One of the very first circuits I ever built was a bare 555, wired to a 9V battery, with a loudspeaker (8 ohms, crappy little quarter W job) between output and ground. I soldered flying wires, about 10cm to every other pin and after some fiddling, managed to elicit a variety of groans and whistles just from handling the bare wires.
    Component count = 2 (3 including batter)

    A proper astable circuit was next, one LDR, one capacitor, one resistor. Plus speaker.
    After a while I could recognizably play tunes with it.
    Component count = 4.

    I would suggest having *both* designs on tap. The astable teaches the analogue end of matters, and there’s always a need for that. The u-controller teaches the software side of life. And there’s plenty of need for that.

    Both aren’t the perfect answer, and neither is “wrong”.

    1. I think that the target audience for this twist-a-simple-electronic-plaything-with-your-fingers toy are not ready to understand any of the theory involved for a 555. Not even a two-transistor multivibrator would be suitable for that.

      So there’s no teaching involved here at all. Just a ‘hook’ to get them realise that electronics can be cool…..

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