Quadcopter Ditches Batteries; Flies On Solar Power Alone

It seems kind of obvious when you think about it: why not just stick a solar panel on a quadcopter so it can fly on solar power? Unfortunately, physics is a cruel mistress, and it gets a bit more complex when you look at problems like weight to power ratios, panel efficiency, and similar tedious technical details. This group of National University of Singapore students has gone some way to overcome these technical issues, though: they just built a drone that is powered from solar power alone, with no batteries or other power source.

Their creation is a custom-built quadcopter made with carbon fiber that weighs just 2.6kg (about 5.7lbs), but which has about 4 square meters (about 43 square feet) of solar panels. By testing and hand-selecting the panels with the best efficiency, they were able to generate enough power to drive the four rotors, and have managed to achieve altitudes of up to 10 meters. The students have been working on prototypes of this since 2012, when their first version could only generate 45% of the power needed for flight. So, reaching 100% of flight power in the demo shown below is a significant step.

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Air Conditioner Remote Reverse Engineered Despite Esoteric Protocol

Infra-red remote control is something of a Done Deal when it comes to hardware hacking, it has been comprehensively reverse engineered, and there exist libraries and software packages to seamlessly take care of all its quirks. Just occasionally though, along comes an IR remote whose protocol doesn’t follow that well-worn path

[William Dudley] found himself in this position with an air-conditioning unit remote control. He found it sent a stream of data with all settings of the machine rather than the single command codes you might expect from a familiar TV remote. The solution was to reverse engineer and reimplement the IR codes.

His reverse engineering relied on an Arduino and IR receiver which he used to sniff the packets coming out of the remote. Eventually he was able to recognise some of the functions from the remote, and create his own protocol that can recreate most of the remote’s functions. This was pushed over to a Raspberry Pi Zero which uses an IR LED to command the air conditioner, joining the ranks of his growing home automation setup.

The write-up makes for a fascinating primer on analysis of obscure IR protocols, and is well worth a read for anybody with an interest in the topic. Meanwhile if you want more IR reverse engineering stories, try this tale of a bathroom scale.

UnMaker 2.0 Is Wile E Coyote’s Dead Blow Hammer

Hammers! They’re good for knocking in nails, breaking things apart, and generally smashing up the joint, if you’re in such a mood. Typically, they’re made of iron or steel and come in a variety of sizes depending on the purpose — from tiny chipping hammers for delicate sculpture work, to the heavy-duty sledge for tearing through building materials. But what if you built your own comically large mallet? Enter UnMaker 2.0.

The hammer receiving an eye-catching lick of paint.

Basically, it’s a really big hammer. It’s vaguely reminiscent of a dead blow type design, in that it consists of a moderately shock-absorbing outer shell filled with heavier material. In this case, steel ball bearings find a home inside the shell made out of maple and with a traditional tapered handle. In many ways it’s quite a typical build — other than the fact of its gigantic size and 34-pound head weight. Both of these make it a shoe-in for the ACME catalog. That roadrunner won’t know what hit him.

[Kevin] reports that it is not so much “swung” as it is “raised and allowed to drop”, due to its impressive weight. Clearly, it packs a punch. It’s a solid follow-on from the group’s former work – a truly gigantic utility knife.

Better Motion Through Electrostatic Actuators

If you want something to move with electricity, odds are you’ll be using magnets. Deep inside every servo, every motor, and every linear actuator is a magnet and some coils of wire. There is another way of making things move, though: electrostatics. These are usually seen in tiny MEMS devices, and now we have tiny little electrostatic speakers making their way into phones and other miniature devices.

For [Nathann]’s Hackaday Prize entry, he’s building electrostatic actuators on the cheap, and not just tiny ones, either. He’s building ‘human’ scale electrostatic devices.

The reason electrostatic devices are usually very small is simple: the force of any actuator is dependent on the distance between the plates and the voltage. Moving the plates closer together is right out, or else they would be touching, so the solution to building bigger electrostatic actuators is increasing the voltage. [Nathann] is doing this with a cheap boost converter that’s actually sold as a taser module. These modules are small, output about 800kV, and cost around five bucks.

The prototype for this project is basically a 3D printed box with intersecting fins. These fins are covered in aluminum foil, and the box is filled with oil to prevent arcing. Will it work? That remains to be seen, but this project is a great example of what can be done with some creative part sourcing, a 3D printer, and a tiny bit of know-how. It’s some of the best work the Hackaday Prize has to offer, and we’re amazed that [Nathann] put in the work to make this happen.

You’ve Never See A Solid-State Oscilloscope Like This One

Remember a the time before oscilloscopes had a brain? It’s easy to forget as we’ve become accustomed to a class of simple solid state oscilloscope using a microcontroller as signal processor and a small LCD display to show the resulting waveforms. They are commonly available as inexpensive kits, and while their bandwidth is not huge they give a good account of themselves in low frequency applications. But of course, originally the signal processing was handled in a much simpler way.

[SimpleTronic] reminds us that a small solid state oscilloscope does not need a microcontroller, with a ‘scope on a breadboard that displays waveforms on an LED matrix in a much more traditional manner. This is very much an analogue oscilloscope, in which the X deflection circuitry of the CRT is replaced by a decade counter stepping through the columns of LEDs on the display, and the Y deflection circuitry by some analogue signal conditioning followed by an LM3914 bar graph display chip driving the display rows. There are a few refinements such as a trigger circuit, but it remains a very understandable and surprisingly simple device.

It has a claimed bandwidth of 40 kHz defined by its sweep ranges rather than its analogue bandwidth, and an input voltage range from 50 mVpp to 50 Vpp. It’s hardly a useful instrument due to its low bandwidth, but its strength lies in novelty and in understanding a traditional oscilloscope rather than in its utility. You can see it in action in the video we’ve placed below the break.

‘Scopes of limited use appear from time to time on these pages. A favourite of ours is this soldering iron.

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The Electric Vehicles Of Electromagnetic FIeld: The Selby

A couple of weekends ago on a farm in rural England with a cider orchard and a very good line in free-range pork sausages, there was the first get-together of the nascent British Hacky Racers series of competitions for comedic small electric vehicles. At the event, [Mark Mellors] shot a set of video interviews with each of the attendees asking them to describe their vehicles in detail, and we’d like to present the first of them here.

The Selby is unique among all the Hacky Racers in being a six-wheeler. It’s the creation of [Michael West] of MK Makerspace, and it bears a curious resemblance to a pair of PowaKaddy golf buggies grafted together. The resulting vehicle has four driven wheels and two steering wheels, and though it is hardly a speedy machine this extra drive gives it what is probably the most hefty pulling power of all the contestants. In the video below it appears without bodywork, but we are told that something impressive will sit upon it when it appears at Electromagnetic Field.

View of motors fed with 24 V driving the rear wheels

I should own up, that the Selby is a familiar to Hackaday, as I’m also an MK Makerspace member. I’ve seen it progress from two worn-out golf trolleys to its current state, and seen first hand some of the engineering challenges that has presented. The PowaKaddy buggies of that vintage are extremely well-engineered, with a Curtis controller that is still comfortably within spec even when driving four motors instead of two. Unusually for a Hacky Racer the power comes from a pair of huge lead-acid batteries, as these were the power source supplied with the PowaKaddy from new and it made little sense to change them. Gearing is fixed at golf-course speeds, and braking comes from a pair of brakes fitted on the motors. The motors themselves are simple DC affairs, with significant weatherproofing.

Cutting and shutting the two PowaKaddys was straightforward enough, but introduced a warp to the chassis that was solved by your Hackaday scribe hanging on the end of a lever formed from a long piece of 4-by-2 while [Mike] and friends stood on the other end of the Selby.

As a driving experience it’s exciting enough but lacks the speed of some of its competitors. Where it really comes into its own though is off-road, as the multi-wheel drive and broad treaded tyres power it across mud and offer powersliding opportunities on wet grass.

We’ve covered a couple of Hacky Racers so far in our mini-series on the Electric Vehicles of Electromagnetic Field, and we’ll bring you a few more before the event. Meanwhile feast your eyes on a Sinclair C5, and an Austin 7 inspired mobility scooter conversion.

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Electric Shower Head Teardown Makes Us Wince

We have bought some really amazing stuff from the Chinese online shops. We’ve also bought stuff that was… less than satisfactory, let’s say. At the prices you pay, you usually just chalk up the bad stuff as a cost of doing business. But [DiodeGoneWild] has a teardown of something that could be very dangerous if it wasn’t up to snuff: an electrically heated shower head. He says they are common in Latin America and have the nickname “suicide showers.”

We’ve seen the cute showerheads that change color, but those take batteries. What we are talking about here connects to the 220V main and draws 30A to instantly heat your shower water. Environmentally, that’s great since you don’t have a tank of water you keep heating and reheating just in case you need hot water. But you wouldn’t throw an AC radio in the tub, so you have to wonder just how safely this thing’s built. Well, you don’t have to wonder, because the videos below are going to show us.

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