Looking for a cheap way to keep an eye on something? [Kevin Hester] pointed us to a way to make a WiFi webcam for under $10. This uses one of the many cheap ESP32 dev boards available, along with the Internet of Things platform PlatformIO and a bit of code that creates an RTSP server. This can be accessed by any software that supports this streaming protocol, and a bit of smart routing could put it on the interwebs. [Kevin] claims that the ESP32 camera dev boards he uses can be found for less than $10, but we found that most of them cost about $15. Either way, that’s cheaper than most commercial streaming cameras.
Create An Aurora Of Your Own
Throughout our day-to-day experiences, we come across or make use of many scientific principles which we might not be aware of, even if we immediately recognize them when they’re described. One such curiosity is that of caustics, which refers not only to corrosive substances, but can also refer to a behavior of light that can be observed when it passes through transparent objects. Holding up a glass to a light source will produce the effect, for example, and while this is certainly interesting, there are also ways of manipulating these patterns using lasers, which makes an aurora-like effect.
The first part of this project is finding a light source. LEDs proved to be too broad for good resolution, so [Neuromodulator] pulled the lasers out of some DVD drives for point sources. From there, the surface of the water he was using to generate the caustic patterns needed to be agitated, as the patterns don’t form when passing through a smooth surface. For this he used a small speaker and driver circuit which allows precise control of the ripples on the water.
The final part of the project was fixing the lasers to a special lens scavenged from a projector, and hooking everything up to the driver circuit for the lasers. From there, the caustic patterns can be produced and controlled, although [Neuromodulator] notes that the effects that this device has on film are quite different from the way the human eye and brain perceive them in real life. If you’re fascinated by the effect, even through the lens of the camera, there are other light-based art installations that might catch your eye as well.
Custom Jig Makes Short Work Of Product Testing
When you build one-off projects for yourself, if it doesn’t work right the first time, it’s a nuisance. You go back to the bench, rework it, and move on with life. The equation changes considerably when you’re building things to sell to someone. Once you take money for your thing, you have to support it, and anything that goes out the door busted is money out of your pocket.
[Brian Lough] ran into this fact of life recently when the widget he sells on Tindie became popular enough that he landed an order for 100 units. Not willing to cut corners on testing but also not interested in spending days on the task, he built this automated test jig to handle the job for him. The widget in question is the “Power BLough-R”, a USB pass-through device that strips the 5-volt from the line while letting the data come through; it’s useful for preventing 3D-printers from being backfed when connected to Octoprint. The tester is very much a tactical build, with a Nano in a breakout board wired to a couple of USB connectors. When the widget is connected to the tester, a complete series of checks make sure that there are no wiring errors, and the results are logged to the serial console. [Brian] now has complete confidence that each unit works before going out the door, and what’s more, the tester shaved almost a minute off each manual test. Check in out in action in the video below.
We’ve featured quite a few of [Brian]’s projects before. You may remember his Tetris-themed YouTube subscriber counter, or his seven-segment shoelace display.
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This Creepy Skull Shows Time With Its Eyes
Sometimes you have an idea, and despite it not being the “right” time of year you put a creepy skull whose eyes tell the time and whose jaw clacks on the hour into a nice wooden box for your wife as a Christmas present. At least, if you’re reddit user [flyingalbatross1], you do!
The eyes are rotated using 360 degree servos, which makes rotating the eyes based on the time pretty easy. The servos are connected to rods that are epoxied to the spheres used as eyes. Some water slide iris decals are put on the eyes offset from center in order to point in the direction of the minutes/hours. An arduino with a real time clock module keeps track of the time and powers the servos.
Check out the video after the break:
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Portable Ham Antenna Gets A Workout
Ham radio isn’t just one hobby. It is a bunch of hobbies ranging from chatting to building things, bouncing signals off the moon, and lots of things in between. Some of these specialties, such as supporting disaster relief or putting odd locations “on the air”, require portable operation. To encourage disaster readiness, hams participate in Field Days which is a type of contest that encourages simulated emergency conditions. So how do you erect an antenna when you just have a few hours to set up a temporary station? [KB9VBR] shows how he and his friend used a Chameleon Emcomm III portable HF antenna for Winter Field Day. You can see the video review, below.
Unlike some portable antennas, this one is almost 100 feet of wire (73 feet of radiator and a 25 foot counterpoise). The entire affair is meant to be put up and taken down repeatedly.
This Blinken Grid Is All Analog
The personal computers of today are economical with their employ of the humble LED. A modern laptop might have a power LED, and a hard drive indicator if you’re lucky. It was the mainframes of the ’60s and ’70s that adhered to the holy Doctrine of Blinken, flickering lamps with abandon to indicate machine activity to the skilled operators of yore. [Matseng] wanted to recreate this aesthetic, and went about it in an entirely analog fashion.
The project is built around an 8×8 LED grid, that was soldered up using a 3D printed jig for dimensional accuracy. Fitted to each column is a PNP flip flop that pulls the column to VCC, while each row has an NPN flip flop which pulls it to ground. Due to variances in component values and tolerances, the oscillators are all out of sync, leading to a remarkably pleasing blinkenlights effect.
We’re a big fan of the raw aesthetic, but [Matseng] has also fitted the grid with a diffuser which more clearly represents that vintage computer aesthetic. We’re a big fan of the blinken here, such as this loving recreation of the PDP-8/I. Video after the break. Continue reading “This Blinken Grid Is All Analog”
A 3D Printed Robotic Chariot For Your Phone
As we’ve said many times in the past, the wide availability of low-cost modular components has really lowered the barrier to entry for many complex projects which previously would have been nigh-on impossible for the hobbyist to tackle. The field of robotics has especially exploded over the last few years, as now even $100 can put together a robust robotics experimentation platform which a decade ago might have been the subject of a DARPA grant.
But what if you want to go even lower? What’s the cheapest and easiest way to put together something like a telepresence robot? That’s exactly what [Advance Robotics] set out to determine with their latest project, and the gadget’s final form might be somewhat surprising. Leveraging the fact that nearly everyone has a device capable of video calls in their pocket, the kit uses simple hardware and 3D printed components to produce a vehicle that can carry around a smartphone. With the phone providing the audio and video link, the robot only needs to handle rolling around in accordance with the operators commands.
The robot chassis consists of a few simple 3D printed components, including the base which holds the phone and electronics, the wheels, and the two rear “spoons” which are used to provide a low-friction way of keeping the two-wheeled device vertical. To get it rolling, two standard DC gear motors are bolted to the sides. With the low cost of printer filament and the fact that these motors can be had for as little as $2 online, it’s hard to imagine a cheaper way to get your electronics moving.
As for the electronics, [Advance Robotics] is using the Wemos D1 Mini ESP8266 development board along with L298N motor controller, another very low-cost solution. The provided source code pulls together a few open source libraries and examples to provide a simple web-based user interface which allows the operator to connect to the bot from their browser and move it around with just a few clicks of the mouse.
If you like the idea of printing a rover to explore your living room but want something a bit more advanced, we’ve seen printable robotics platforms that are sure to meet your needs, no matter what your skill level is.
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