Learn Water Purification Techniques With This STEM Learning Kit

December 7, 2019 by Gerrit Coetzee 7 Comments

We see a lot of great STEM education projects. These projects have a way of turning into something much larger. How many commercial devices and machines are built on Raspberry Pi’s and Arduinos? [Ryan Beltrán] is using common materials to teach people how to clean water. This particular kit demonstrates a water purification process called electro-coagulation.

When current is passed through two electrodes suspended in water it changes the surface charge on the suspended solids. This causes the solids, metals, and oils to clump together which makes them considerably easier to treat and clean.

The kit consists of a jar, electrodes, some 3D printed parts, and a pre-flashed Arduino. There’s also salts and filters to finalize the purification process. Students can start the experiment right away and if they’re inspired they’ll have all the tools to try more advanced techniques.

Often STEM kits lean heavily to robotics or computer science, but there are so many vast and interesting fields out there with problems that need to be solved.

Beer Keg Becomes High-Performance Pizza Oven

December 7, 2019 by Lewin Day 14 Comments

Pizza varies all around the world, with several cities having put their own mark on the Italian dish. To make an authentic pie in the Neapolitan style requires extremely high temperatures in order to cook the pizza through in just a couple of minutes. Armed with a beer keg and some ingenuity, [AndrewW1977] got down to work, building a rig that could get the job done.

The build starts by cutting the keg in half. A series of zigzag steel pieces are welded inside, in order to give the refractory cement more surface area to stick to. With the cement poured and set, a handle was welded to the keg for ease of use, as well as a thermometer to monitor internal temperatures.

Initial attempts to cook using the rig used a wood-fired rocket stove design. This had the drawback of taking up to 45 minutes to reach the appropriate temperature, so the build then switched to using God’s Gas, clean burning propane, as a fuel source. With a jet-style burner installed in the base, the oven was ready to start turning out pizzas.

The idea of cooking a hot, fresh pizza in just a couple of minutes has us salivating at the possibilities. We’ve seen other high-speed pizza ovens, too. Video after the break.

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Upgrade Your Shades To Find Lost Items

December 7, 2019 by Sharon Lin 8 Comments

Ever wish you could augment your sense of sight?

[Nick Bild]’s latest hack helps you find objects (or people) by locating their position and tracking them with a laser. The device, dubbed Artemis, latches onto your eyeglasses and can be configured to locate a specific object.

Images collected from the device are streamed to an NVIDIA Jetson AGX Xavier board, which uses a SSD300 (Single Shot MultiBox Detection) model to locate objects. The model was pre-trained with the COCO dataset to recognize and localize 80 different object types given input from images thresholded in OpenCV. Once the desired object is identified and located, a laser diode activates.

Probably due to the current thresholds, the demo runs mostly work on objects placed further apart against a neutral background. It’s an interesting look at applications combining computer vision with physical devices to augment experiences, rather than simply processing and analyzing data.

The device uses two servos for controlling the laser: one for X-axis control and the other for Y-axis control. The controls are executed from an Adafruit Itsy Bitsy M4 Express microcontroller.

Perhaps with a bit more training, we might not have so much trouble with “Where’s Waldo” puzzles anymore.

Check out some of our other sunglasses hacks, from home automation to using LCDs to lessening the glare from headlights.

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Simple Pogo Programmer For ESP8266 Modules

December 7, 2019 by Tom Nardi 19 Comments

ESP8266 development boards like the Wemos D1 Mini and NodeMCU are an excellent way to get a one-off project up and rolling quickly, but their size and relative complexity mean they aren’t necessarily a good choice for even short-run production hardware. On the other hand, programming the bare ESP modules can be something of a pain. But thanks to [Greg Frost], flashing those tiny little boards just got a lot easier.

His 3D printed design uses pogo pins to securely connect to the board’s castellated edges, which also holds it in place during the programming process. On the back side there’s just a few jumper wires and a couple of resistors, which ultimately lead to the FT232R FTDI board that actually connects the chip to the computer so you can program it.

We’d like to see a back panel that encloses the wiring, and perhaps an alternate version that deletes the space for the FTDI board in favor of a row of header pins. Both easy enough modifications to the basic design should [Greg] or anyone else feel so inclined. But even as it is, this is a great little programmer that can be sourced and assembled easily and cheaply.

This isn’t the first 3D printed ESP8266 programmer we’ve seen, and there are some improvised versions which are even cheaper to put together, but this design has a certain professional look that we think will be right at home on your bench.

This CPU Has Only One Instruction

December 7, 2019 by Jenny List 37 Comments

Most of us will be familiar at some level with the operation of a basic CPU, usually through exposure to microprocessors of the type that find their way into our projects. We can look at its internal block diagram and get how it works, see the registers and ALU, follow the principles of a von Neumann architecture, and understand that it has an instruction set with different instructions for each of its functions. We all know that this only describes one type of CPU though, and thus it’s always interesting to see alternatives. [Ike Jr] then has a project that should provide a lot of interest, it’s a CPU that only has a single instruction. It can only move data from one place to another, which seems to preclude any possibility of computation. How on earth can it work?

The machine has a set of registers as well as memory, and it achieves computation by having specific registers where we might expect to see instructions. For example the AND register is a two-position stack, that when it is full computes the AND of its two pieces of data and places the result in a general purpose register. The write-up goes into significant detail on the CPU’s operation, and while it’s unlikely the world will move en masse to this architecture it’s still a very interesting read. For now this is a machine that exists in software simulation rather than in silicon, and he’s working to release it so enthusiasts for unusual CPUs can have a go.

The idea of having registers that compute reminds us of a transport triggered architecture machine, being not the same as a one instruction CPU with a more conventional computing instruction.

Abstract PCB header image: Harland Quarrington/MOD [OGL v1.0].

Visiting The FACOM 128B 1958 Relay Computer

December 6, 2019 by Al Williams 9 Comments

If you study the history of computing you might have heard of the FACOM 128B, a Japanese relay computer from 1958. It holds the distinction of being a contender for the oldest computer that still works in its original form, as it resides in a Fujitsu building in Numazu Japan. [CuriousMarc] visited the old computer and created a video about it as well as painting a picture of other contemporary machines. You can see the video below.

[Marc] explains how a relay machine was already behind the times in 1958, and also shows how the 5,000 relay machine is laid out. The machine on display came from a Tokyo university and did the kind of computations you might use a computer for today to do engineering design.

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Behind Amazon’s Doors Is A Library

December 6, 2019 by Al Williams 7 Comments

Some people love Amazon, while others think it has become too big and invasive. But you have to admit, they build gigantic and apparently reliable systems. Interestingly, they recently released a library of white papers from their senior staff called the Builder’s Library.

According to their blog post:

The Amazon Builders’ Library is a collection of living articles that take readers under the hood of how Amazon architects, releases, and operates the software underpinning Amazon.com and AWS. The Builders’ Library articles are written by Amazon’s senior technical leaders and engineers, covering topics across architecture, software delivery, and operations. For example, readers can see how Amazon automates software delivery to achieve over 150 million deployments a year or how Amazon’s engineers implement principles such as shuffle sharding to build resilient systems that are highly available and fault tolerant.

The Amazon Builders’ Library will continue to be updated with new content going forward.

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