Compiling NodeMCU For The ESP32 With Support For Public-Private Key Encryption

January 3, 2019 by Sean Boyce 7 Comments

When I began programming microcontrollers in 2003, I had picked up the Atmel STK-500 and learned assembler for their ATtiny and ATmega lines. At the time I thought it was great – the emulator and development boards were good, and I could add a microcontroller permanently to a project for a dollar. Then the ESP8266 came out.

I was pretty blown away by its features, switched platforms, except for timing-sensitive applications, and it’s been my chip of choice for a few years. A short while ago, a friend gave me an ESP32, the much faster, dual core version of the ESP8266. As I rarely used much of the computing power on the ESP8266, none of the features looked like game changers, and it remained a ‘desk ornament’ for a while.

About seven weeks ago, support for the libSodium Elliptic Curve Cryptography library was added. Cryptography is not the strongest feature of IoT devices, and some of the methods I’ve used on the ESP8266 were less than ideal. Being able to more easily perform public-private key encryption would be enough for me to consider switching hardware for some projects.

However, my preferred automated build tool for NodeMCU wasn’t available on the ESP32 yet. Compiling the firmware was required – this turned out to be a surprisingly user-friendly experience, so I thought I’d share it with you. If I had known it would be so quick, this chip wouldn’t have sat on my desk unused quite so long! Continue reading “Compiling NodeMCU For The ESP32 With Support For Public-Private Key Encryption” →

Open Source Company Gives Us A Peek At Financial Innards

January 1, 2019 by Kerry Scharfglass 13 Comments

Here at Hackaday we are willing to bet that in a universe free of all monetary constraints, many of our readers would leave their day jobs in order to pursue their hardware hobbies full time. Obviously this is only practical for a lucky minority of people (for a wide variety of reasons) but we’re willing to bet that a significant stumbling block is figuring how to do it in the first place. You quit your job, but then what? If more information about starting and sustaining small hardware business’ was available more people would take the plunge to start one. There are software companies with salary transparency but this is only part of the picture and we can’t think of many hardware companies that offer the same. What we really want is to get an image of the entire business end to end; from suppliers to COGS to salary. And we want to see it for hardware.

Years ago the first and second Hackaday Prizes captured an entrant named FarmBot whose goal was to build open source robotic farming equipment to make it easier for anyone to grow their own food. A few successful Kickstarters and years later they’ve been shipped multiple versions of the Genesis and Genesis XL robotic farming system and have a sustainable business! And now they’ve decided to open source their business operations too. Suffice to say, this provides quite an uncommon view into the guts of what makes a small open source hardware business tick. Let’s take a closer look!

There is a wealth of information exposed in the company documentation; it’s as though they took their internal wiki and made it public, which we suppose is exactly what happened. The most interesting part for our readers might be the statistics page that tracks costs and quantities for their products. This is where the magic lives. You can use to it see that so far they’ve sold 124 Genesis XL machines at an average selling price of $3,834.34 for $475,458.30 of revenue (it cost $187,200 to build their run of 200 machines). You can also see that each machine has 1,415 parts and takes about 25 hours to assemble. This page is where the true guts of the business live.

Everything else is here too. Here’s where you can learn about what vendors FarmBot uses use logistics, or power, or web infrastructure monitoring. And this is the page with the infamous salary calculation formulas if you want to guess what you’d make as an employee. Then there’s a bunch of boring but important stuff. Fulfillment processes live here, and the consumables they use to support that fulfillment are listed here (with costs!).

One reason we enjoy open source so much is that it affords a wonderful opportunity for people to learn instead of keeping the important parts of a product or process perpetually under wraps. We’re hoping that documentation like this becomes more prevalent and foster an explosion of small hardware companies to follow it.

Portmanteau Spewing PunBot

December 26, 2018 by Brian McEvoy 9 Comments

When Python was created, [Guido van Rossum] knew that one day it would be fully realized and take its final form. Clearly, that day has arrived since there now exists a way to send a word query and receive a lengthy list of potential portmanteaus. Some may regard this as merely quaint, but it will be the most important thing to happen in binary until the singularity.

Perhaps we are overpromising a smidge, but it may be fun to spend an afternoon getting your own whimsicalibrated pun resource churning out some eye-roll-worthy word combos. The steps are broken up neatly and explained at a high level with links for more in-depth explanations so a novice can slog through it, but a whiz can wrap it up while the boss is looking the other way.

We truly live in the future, but we may continue writing our own brand of artisanal puns which are number one in someone’s book.

Young Entrepreneurs Learn What Really Goes Into Making A Product

December 15, 2018 by Donald Papp 7 Comments

Just to be clear, the primary goal of the Papas Inventeurs (Inventor Dads) was to have the kids make something, have fun, and learn. In that light, they enjoyed a huge success. Four children designed, made, and sold laser-cut napkin rings from a booth at the Ottawa Maker Faire as a fun learning process (English translation, original link in French.) [pepelepoisson] documented the entire thing from beginning to end with plenty of photos. Things started at proof of concept, then design brainstorming, prototyping, manufacture, booth design, and finally sales. While adults were involved, every step was done by the kids themselves.

It all began when the kids were taken to a local fab lab at the École Polytechnique and made some laser-cut napkin holders from plywood for personal use. Later, they decided to design, manufacture, and sell them at the Ottawa Maker Faire. Money for the plywood came from piggy banks, 23 different designs made the cut, and a total of 103 rings were made. A display board and signs made from reclaimed materials rounded out the whole set.

In the end, about 20% of people who visited and showed interest made a purchase, and 60 of the 103 pieces were sold for a profit of $126. Of course, the whole process also involved about 100 hours of combined work between the kids and parents and use of a laser cutter, so it’s not exactly a recipe for easy wealth. But it was an incredibly enriching experience, at least figuratively, for everyone involved.

Possibly the biggest takeaway was the way manufacturing involved much more than just pressing “GO” on a laser cutter. Some pieces needed sanding after laser cutting, and each piece got two coats of varnish. If you missed it, [Bob Baddeley] showed how labor, and not materials, ends up being the most expensive part of a product.

Build Your Own Anechoic Chamber

December 14, 2018 by Bryan Cockfield 16 Comments

For professional-level sound recording, you’ll need professional-level equipment. Microphones and mixing gear are the obvious necessities, as well as a good computer with the right software on it. But once you have those things covered, you’ll also need a place to record. Without a good acoustic space, you’ll have all kinds of reflections and artefacts in your sound recordings, and if you can’t rent a studio you can always build your anechoic chamber.

While it is possible to carpet the walls of a room or randomly glue egg crate foam to your walls, [Tech Ingredients] tests some homemade panels of various shapes, sizes, and materials against commercially available solutions. To do this he uses a special enclosed speaker pointed at the material, and a microphone to measure the sound reflections. The tests show promising results for the homemade acoustic-absorbing panels, at a fraction of the cost of ready-made panels.

From there, we are shown how to make and assemble these panels in order to get the best performance from them. When dealing with acoustics, even the glue used to hold everything together can change the properties of the materials. We also see a few other cost saving methods in construction that can help when building the panels themselves as well. And, while this build focuses on acoustic anechoic chambers, don’t forget that there are anechoic chambers for electromagnetic radiation that use the same principles as well.

Thanks to [jafinch78] for the tip!

Continue reading “Build Your Own Anechoic Chamber” →

A Lecture By A Fun Guy

December 14, 2018 by Brian McEvoy 9 Comments

Many people hear “fungus” and think of mushrooms. This is akin to hearing “trees” and thinking of apples. Fungus makes up 2% of earth’s total biomass or 10% of the non-plant biomass, and ranges from the deadly to the delicious. This lecture by [Justin Atkin] of [The Thought Emporium] is slightly shorter than a college class period but is like a whole semester’s worth of tidbits, and the lab section is about growing something (potentially) edible rather than a mere demonstration. The video can also be found below the break.

Let’s start with the lab where we learn to grow fungus in a mason jar on purpose for a change. The ingredient list is simple.

2 parts vermiculite
1 part brown rice flour
1 part water
Spore syringe

Combine, sterilize, cool, inoculate, and wait. We get distracted when cool things are happening so shopping around for these items was definitely hampered by listening to the lecture portion of the video.

Continue reading “A Lecture By A Fun Guy” →

Lessons Learned From A 1-Day RTL-SDR Enclosure Project

December 14, 2018 by Donald Papp 9 Comments

[ByTechLab] needed an enclosure for his R820T2 based RTL-SDR, which sports an SMA connector. Resolving to design and 3D print one in less than a day, he learned a few things about practical design for 3D printing and shared them online along with his CAD files.

The RTL-SDR is a family of economical software defined radio receivers, and [ByTechLab]’s’ enclosure (CAD files available on GrabCAD and STL on Thingiverse) is specific to his model. However, the lessons he learned are applicable to enclosure design in general, and a few of them specifically apply to 3D printing.

He started by making a basic model of the PCB and being sure to include all large components. With that, he could model the right voids inside the enclosure to ensure a minimum of wasted space. The PCB lacks any sort of mounting holes, so the model was also useful to choose where to place some tabs to hold the PCB in place. That took care of the enclosure design, but it also pays to be mindful of the manufacturing method so as to play to its strengths. For FDM 3D printing, that means most curved shapes and rounded edges are trivial. It also means that the biggest favor you can do yourself is to design parts so that they can be printed in a stable orientation without any supports.

This may be nothing that an experienced 3D printer and modeler doesn’t already know, but everyone is a novice at some point and learning from others’ experiences can be a real timesaver. For the more experienced, we covered a somewhat more in-depth guide to practical 3D printed enclosure design.

[ByTechLab]’s desire for a custom enclosure was partly because RTL-SDR devices come in many shapes and sizes, as you can see in this review of 19 different units (of which only 14 actually worked.)