How to turn an Arduino-based proof of concept into a final prototype
digitaljunky.ioAre there any books for non-engineers, that go from basic concepts up to PCB design?
UPDATE: Not sure if it's going up to PCB design but apparently this one[1] seems to be the most praised on Amazon UK.
[1] http://www.amazon.co.uk/gp/product/0071771336?psc=1&redirect...
I learned a lot about the basics with "Getting started in Electronics" by Forrest M. Mims III, it's very (very) accessible and I find the drawings very amusing.
Or else you have the Bible of the trade, or "The Art of Electronics" by Paul Horowitz and Winfield Hill that just came out for a third edition. It's an incredibly comprehensive guide but you'd better have some free time ahead if you want to read through it all :)
Agree with you. The Forrest Mims books are concise and written in a very simple manner without dumbing things down. His collection of the basics which is about four small volumes, will cost you about $50 in total. Money very well spent.
I can recommend Practical Electronics for Inventors. It is very helpful in getting practical prototypes designed pretty quick. I sometimes still refer to it when I need something simple I haven't designed in a while.
Check out Chris Gammell's Contextual Electronics course about board design with KiCad: https://contextualelectronics.com/ The KiCard course is now free and great at walking through how to use KiCad to design boards: https://contextualelectronics.com/course/kicad-tutorial/
1. Contextual Electronics does have a really good course on kicad.
2. Kicad is a very good PCB software package.
Word of warning though, kicad is currently in a state of "flux" with the latest stable from 2013, and the bleeding edge versions having all of the features you want to use. I personally use nightly builds and the 2013 version quite often, and neither are what I would call professionally stable.
One cool thing about the new version is that it uses s-expressions for its file format. I was disappointed to find that I couldn't perform rotation on a group of footprints at once, but once I took a look at the file format I found it was easy to load into Racket, do a little trig, and spit out the rotated forms: https://github.com/technomancy/atreus/blob/master/atreus.rkt...
Next question is how to go from final prototype into production... that can be pretty hard in practice.
Indeed, calling a prototype "final" before looking at the manufacturing side of things might not be wise.
Right. This is something that looks like the final product, but isn't ready for manufacture.
* If you run a 9V battery into a linear regulator to get 5V, there goes 55% of your energy and battery life. Consider 4 AAA cells. Work on reducing standby power consumption. When idle, put the CPU to sleep until IR is sensed. (An ATmega can do this.) Things which burn battery power when idle fail as consumer products.
* "I could (and probably should) use an ATtiny for such an application but I only had some ATMega328 in my parts bin."
* Prototype plastic things with 3D printing. Manufacture them by injection moulding. The little injection moulder at a TechShop could bang out about one box a minute. Any commercial shop can turn out thousands in a day. Making the mould is either work or expense, but you come out way ahead after a few hundred parts.
> Making the mould is either work or expense, but you come out way ahead after a few hundred parts.
Where are you getting your mould? Everywhere I deal with wants $5K+ USD NRE.
You can 3D print a lot of stuff for $5K USD.
Get a TechShop membership, take the classes in injection moulding, CNC I, CNC II, and CNC mill. You get free access to Autodesk Moldflow, an injection moulding simulator. Learn to use it. Design and mill your mold. Make some parts using TechShop's injection molding machine. Make a new mold if you're not getting what you want.
Completely straight sides make injection moulding harder. The tooling for straight sides has to come apart to release the finished part. But a shape that's smaller at the bottom can be made in a far simpler mould. This is why cheap items such as plastic glasses are tapered so much. Look at plastic parts around you, and notice that most of them are shaped to come easily out of a simple mould.
Consider making the outer shell by vacuum-forming. That's cheap and easy, and the tooling can be made of wood. TechShop has that capability, too. It works better for shapes that aren't as sharp-cornered as a cube, so consider modifying the shape to have rounded corners.
Both of these processes will produce a much smoother finish and a stronger part than 3D printing.
Welcome to manufacturing.
My shop recently did some work fixing some injection molds that a customer bought from a Chinese manufacturer for about that price. I was shocked by how cheap they were. Of course we were being paid to fix them because they weren't quite right, but still, $5k. Wow. If you want quality 3D printed parts, that amount of money burns up very quickly.
yeah I'm right in the middle of that problematic...if you have any advice I'm all ears (so to speak)!
Honest advice? Hire someone to do it. There are so many things that you won't know about how to make things manufacture-able it would be worth your time and money to just pay a contractor/employee to optimize things for you.
(shameless plug, my username @ gmail.com if you would like to discuss what services I can offer you)
I'm a 23y.o guy launching its first product so saying that I don't have any money to hire someone is an understatement :)
On the other hand, I have quite a lot of free time and a very versatile brain so I'll take my chance with that.
If you want to go that route, have a contractor review at various stages. It shouldn't take more than an hour or two, and most contractors will do it with the hope that if you make it big you will remember them and their services.
Thanks for the comments @malcolmputer. It would be nice to put some description to your profile, to spare some time stalking your online profile[1].
I'm designing a prototype for an application. If we reach up to the point where optimization/PCB design is needed, I'll drop a mail.
Yeah, I am still working on that. You will notice my HN profile is less than a day old.
Tip: to help make even smaller proof of concepts use a Teensy [1] instead of an Arduino.
Great article, lots of resources in there for someone getting started and your writing style is great too. Please do a follow up if you figure out the production part :)
hey thanks. I sure will add additional details along the road and probably write something else about manufacturing. Since it appears that it can be a very complicated (and costly) adventure, I contacted a local start-up incubator hoping to benefit form their expertise.