Model Hydroelectric Plant Is An Illuminating Educational Tool

July 21, 2020 by Kristina Panos 6 Comments

There’s more than one way to light up a strip of LEDs. Have you tried building your own hydroelectric power plant to do it? Well, now you can. Replicating [Matic Markovič]’s entry into the 2020 Hackaday Prize is bound to teach you something, if not many things, about the way hydroelectric power is generated and the way the variables play into it.

In [Matic]’s model, water from an adjustable-height reservoir flows into a 3D-printed Pelton turbine. The water jet hits the turbine’s cupped fins at a 90° angle, causing the assembly to spin around rapidly. This mechanical energy charges a brushless DC motor that’s connected to an Arduino Nano, which rectifies the AC from the generator and uses it to light up an RGB strip like an equalizer display that represents the power being generated.

This is easily one of the coolest educational displays we’ve ever seen. The reservoir can move up and down over a 55 cm (21.6″) range with the flick of a three-way toggle, which makes it easy to see that the higher the reservoir, the more power is generated. [Matic] has the STLs and INOs in the usual places if you want to make your own. Flow past the break for a demonstration, followed by an exploded render that gets put back together by invisible hands.

Your hydroelectric setup doesn’t need to be fancy, it just needs to work. One man’s trash can be another man’s off-grid phone charger.

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This Soap Dispenser Will Crush Your Germs

July 17, 2020 by Sharon Lin 12 Comments

When it comes to cleaning your hands, [Arnov Sharma] is not messing around. He built an automatic soap dispenser using ultrasonic sensors, a stepper motor for activating the pump, and 3D printed components for housing a bottle of soap – a spectacular display of over-engineering. At least he won’t be needing to stand in line at the supermarket for motion detection soap dispensers anytime soon.

Initially, he had the idea to build the dispenser using a common servo motor-based method. This would involve activating motors to push down on the plunger for the soap bottle to dispense soap. Instead, he for a different approach that ended up being fairly straightforward in theory, although the execution is pretty involved.

Model of the soap dispenser made in Fusion 360

He started off by 3D printing the compartment where the soap bottle would sit and the structural support for the Z-axis rail that would be pushing down on the soap bottle. It’s similar to the type of linear actuator you might find in a 3D printer or PCB mill, where a motor controls a rotating screw that moves the carriage across a belt. (We presume the linear rail came first, and the ultrasonic soap dispenser second.)

In this build, there are two additional rods added to help support the lever pressing down on the soap dispenser.

The setup is controlled by an Arduino, which triggers the movement from the linear actuator if it receives a signal from an ultrasonic sensor. He’s added the model files and Arduino code for other makers curious about building a similar project. Check out his video for the soap dispenser in action – the stepper motor definitely makes for a much more powerful plunge than you might expect.

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Dream Team Members Announced For The 2020 Hackaday Prize

July 10, 2020 by Mike Szczys 1 Comment

The Dream Team program is an exciting new element of the 2020 Hackaday Prize, with twelve people accepted to work full-time on a specific problem for each of our non-profit partners this summer. Each team of three is already deep into an engineering sprint to pull together a design, and to recognize their efforts, they’ll be receiving a $3,000 monthly microgrant during the two-month program.

Join us after the break to meet the people that make up each of the teams and get a taste of what they’re working on. We’ll be following along as they publish detailed work logs on the Dream Team project pages.

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RC Car Becomes Useful Little Mower

July 7, 2020 by Lewin Day 16 Comments

When we think of lawn mowers, our first thought is of heavy, rusty old machines that take the best part of an afternoon to get started. Of course, there’s always another way, as [Mark] ably demonstrates with his own build.

Beginning from an unconventional starting point, [Mark] chose a remote control car, of the type that can flip and drive in both orientations. Having lost the controller, he started by ripping out the original electronics. In its place, an ESP32 receives signals from a FlySky RC receiver, and runs the drive motors with a Sparkfun Monster Motor Shield. Another channel on the receiver is hooked up directly to a drone speed controller driving a brushless motor, outfitted with a sawblade to cut the grass.

It’s a small platform, and one that ordinarily you might doubt could do the job. However, for [Mark]’s purposes, the rig works just fine, and has been doing good work for the last two years! We’ve seen mowers hacked before too, like this autonomous rig out in the wild. Video after break.

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Time Bandit Clock Hits The Aesthetic Jackpot

July 6, 2020 by Kristina Panos 11 Comments

When was the last time you looked forward to looking at a clock? Not to find out the time per se — like gee, maybe it’s beer o’ clock already — but waited with bated breath to gaze upon a particular clock? Never? We don’t blame you, but only because you haven’t seen this fruit machine clock in action yet.

Every 60 seconds, the reels start spinning like some little man inside pulled the lever on a slot machine (or fruit machine, as they’re called across the pond). The reels slow down and stop one by one, left to right, settling on the four digits of time in 24-hour mode. Imagine the suspense of coming to see what time it is just as the reels start spinning!

[timebanditclock] grew this fruit machine out of old-school discrete logic beautifully applied to stripboard. Each of the reels has a DIY binary encoder that uses IR transmit/receive pairs to generate a binary word. These four binary words are compared to a binary clock module using comparators.

We think this is an amazing concept already, but then [timebanditclock] worked overtime by doing it all in discrete logic. Spin past the break to see a demo and stick around for the build video.

Want a challenging clock build that’s a little less challenging? Maybe it’s time to try circuit sculpture.

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Sky Anchor Puts Radios Up High, No Tower Needed

July 3, 2020 by Dan Maloney 65 Comments

When it comes to radio communications on the VHF bands and above, there’s no substitute for elevation. The higher you get your antenna, the farther your signal will get out. That’s why mountaintops are crowded with everything from public service radios to amateur repeaters, and it’s the reason behind the “big stick” antennas for TV and radio stations.

But getting space on a hilltop site is often difficult, and putting up a tower is always expensive. Those are the problems that the Sky Anchor, an antenna-carrying drone, aims to address. The project by [Josh Starnes] goes beyond what a typical drone can do. Rather than relying on GPS for station keeping, [Josh] plans a down-looking camera so that machine vision can keep the drone locked over its launch site. To achieve unlimited flight time, he’s planning to supply power over a tether. He predicts a 100′ to 200′ (30 m to 60 m) working range with a heavy-lift octocopter. A fiberoptic line will join the bundle and allow a MIMO access point to be taken aloft, to provide wide-area Internet access. Radio payloads could be anything from SDR-based transceivers to amateur repeaters; if the station-keeping is good enough, microwave links could even be feasible.

Sky Anchor sounds like a great idea that could have applications in disaster relief and humanitarian aid situations. We’re looking forward to seeing how [Josh] develops it. In the meantime, what’s your world-changing idea? If you’ve got one, we’d love to see it entered in the 2020 Hackaday Prize.

An Off-The-Grid Instant Messaging Plattform

July 2, 2020 by Moritz v. Sivers 19 Comments

Having an open-source communication device that is independent of any network and works without fees sounds like a hacker’s dream come true. Well, this is exactly what [bobricius]’ is aiming at with his Armawatch and Armachat devices.

Recently, [bobricius] built a LoRa based instant messaging device named Armachat. The gadget is controlled by a SAMD21 MCU with native USB and includes a QWERTY keyboard and an LCD display. Communication is based on an RFM95 LoRa transceiver which can reach a range of up to 2 km under ideal conditions. [bobricius] is a wiz when it comes to PCB design and one thing that makes his projects look so good is how he often uses PCBs as enclosures.

Armachat came in two form factors a large desktop and a smaller pocket version. The new Armawatch is another downsized version that perfectly fits on your arm by using a smaller display and keyboard. [bobricius] also did a lot of work on the firmware which now features a message delivery confirmation and the possibility to automatically resend undelivered messages. Future improvements will include message encryption, a store-and-forward function, and GPS position parsing. [bobricius] is also working on completing his portfolio of communicators with a credit-card-sized version.

LoRa is the go-to technology for off-the-grid communication devices and there are already other ongoing projects for using it to construct a mesh network.