Servo-Controlled IoT Light Switches

January 17, 2017 by Lewin Day 27 Comments

The Internet of Things is fun to play with; there’s all manner of devices to automate and control remotely. It can be sketchy, though — make a mistake when coding your automatic plant watering system and you could flood your house. Make a mistake with a space heater and you could burn it down. Combine these risks with the fact that many people live in rental properties, and it can be a difficult proposition to bring the Internet of Things to your home.

[Suyash] came up with a way around this by building 3D printed light switch covers that add servo control. It’s a great solution that it doesn’t require the modification of any mains wiring, and interfaces with the standard switches in the normal way. It makes it a lot safer this way — there are municipal wiring codes for a reason. This is a great example of what you can do with a 3D printer, above and beyond printing out Yoda heads and keychains.

The backend of things is handled by the venerable ESP8266, with [Suyash]’s custom IoT library known as conduit doing the heavy lifting. The library is a way to quickly build IoT devices with web interfaces, and [Suyash] claims it’s possible to be blinking an LED from the cloud within 5 minutes using the tool.

For another take on an IoT light switch, check out this Hackaday Prize entry from 2016.

Shmoocon 2017: The Ins And Outs Of Manufacturing And Selling Hardware

January 17, 2017 by Brian Benchoff 29 Comments

Every day, we see people building things. Sometimes, useful things. Very rarely, this thing becomes a product, but even then we don’t hear much about the ins and outs of manufacturing a bunch of these things or the economics of actually selling them. This past weekend at Shmoocon, [Conor Patrick] gave the crowd the inside scoop on selling a few hundred two factor authentication tokens. What started as a hobby is now a legitimate business, thanks to good engineering and abusing Amazon’s distribution program.

The product in question is the U2F Zero, an open source U2F token for two-factor authentication. It’s built around the Atmel/Microchip ATECC508A crypto chip and is, by all accounts, secure enough. It’s also cheap at about $0.70 a piece, and the entire build comes to about $3 USD. All of this is hardware, and should be extremely familiar to the regular Hackaday reader. This isn’t the focus of [Conor]’s talk though. The real challenge is how to manufacture and sell these U2F dongles, a topic we looked in on back in September.

The circuit for this U2F key is basically just a crypto chip and a USB microcontroller, each of which needs to be programmed separately and ideally securely. The private key isn’t something [Conor] wants to give to an assembly house, which means he’s programming all these devices himself.

For a run of 1100 units, [Conor] spent $350 on PCB, $3600 for components and assembly, $190 on shipping and tariffs from China, and an additional $500 for packaging on Amazon. That last bit pushed the final price of the U2F key up nearly 30%, and packaging is something you have to watch if you ever want to sell things of your own.

For distribution, [Conor] chose Fulfillment By Amazon. This is fantastically cheap if you’re selling a product that already exists, but of course, [Conor]’s U2F Zero wasn’t already on Amazon. A new product needs brand approval, and Amazon would not initially recognize the U2F Zero brand. The solution to this was for [Conor] to send a letter to himself allowing him to use the U2F Zero brand and forward that letter to the automated Amazon brand bot. Is that stupid? Yes. Did it work? Also yes.

Sales were quiet until [Conor] submitted a tip to Hacker News and sold about 70 U2F Zeros in a day. After that, sales remained relatively steady. The U2F Zero is now a legitimate product. Even though [Conor] isn’t going to get rich by selling a dozen or so U2F keys a day, it’s still an amazing learning experience and we’re glad to have sat in on his story of bootstrapping a product, if only for the great tip on getting around Amazon’s fulfillment policies.

Microfluidics “Frogger” Is A Game Changer For DIY Biology

January 16, 2017 by Dan Maloney 30 Comments

See those blue and green dots in the GIF? Those aren’t pixels on an LCD display. Those are actual drops of liquid moving across a special PCB. The fact that the droplets are being manipulated to play a microfluidics game of “Frogger” only makes OpenDrop v 2.0 even cooler.

Lab biology is mainly an exercise in liquid handling – transferring a little of solution X into some of solution Y with a pipette. Manual pipetting is tedious, error prone, and very low throughput, but automated liquid handling workstations run into the hundreds of thousands of dollars. This makes [Urs Gaudenz]’s “OpenDrop” microfluidics project a potential game changer for the nascent biohacking movement by offering cheap and easy desktop liquid handling.

Details are scarce on the OpenDrop website as to exactly how this works, but diving into the literature cited reveals that the pads on the PCB are driven to high voltages to attract the droplets. The PCB itself is covered with a hydrophobic film – Saran wrap that has been treated with either peanut oil or Rain-X. Moving the droplets is a simple matter of controlling which pads are charged. Splitting drops is possible, as is combining them – witness the “frog” getting run over by the blue car.

There is a lot of cool work being done in microfluidics, and we’re looking forward to see what comes out of this open effort. We’ve covered other open source efforts in microfluidics before, but this one seems so approachable that it’s sure to capture someone’s imagination.

Continue reading “Microfluidics “Frogger” Is A Game Changer For DIY Biology” →

3D Print Your E-Drum Pads

January 16, 2017 by Lewin Day 2 Comments

The concept behind DIY electronic drum kits is fairly simple — small piezoelectric elements are used to generate a voltage when the drumpads are struck. That’s easy enough, but the mechanical design can be a difficult problem to approach. To solve that, [ryo.kosaka.10] decided to design an E-drum pad made with paper & 3D printed parts.

As far as E-drum triggers go, it follows the basic rules — a piezo element used as a trigger with some foam used for damping. For the striking surface, a Tama-brand mesh drum head is used. Being an off-the-shelf drum head, it has a good feel and playability. But the shell is where the creativity really shines through. While the top and bottom parts are 3D printed in the usual way, the main shell of the drum is made with several layers of thick paper laminated together with glue. This creates a surprisingly strong, sturdy shell and is also much faster and less wasteful than waiting for a similar part to 3D print.

To round out the guide, instructions are given on how to wire the piezo triggers up for either a regular E-drum sound module or an Arduino. It’s a nice touch, as those inexperienced with E-drums may not be entirely familiar with how they work – this way, anyone can give the project a try.

Keen for something bigger? Back in 2014 we saw this awesome 5-piece e-drum kit built out of buckets.

Shmoocon 2017: Software Defined Radio For Terahertz Frequencies

January 16, 2017 by Brian Benchoff 29 Comments

Before Bluetooth, before the Internet of Things, and before network-connected everything, infrared was king. In the 90s, personal organizers, keyboards, Furbys, and critical infrastructure was built on infrared. Some of these devices are still around, hiding in plain sight. This means there’s a lot of opportunities for some very fun exploits. This was the focus of [Mike Ossmann] and [Dominic Spill]’s talk at this year’s Shmoocon, Exploring The Infrared World. What’s the hook? Using software-defined radio with terahertz frequencies.

Infrared communication hasn’t improved since the days of IrDA ports on laptops, and this means the hardware required to talk to these devices is exceptionally simple. The only thing you need is an IR phototransistor and a 4.7k resistor. This is enough to read signals, but overkill is the name of the game here leading to the development of the Gladiolus GreatFET neighbor. This add-on board for the GreatFET is effectively a software defined IR transceiver capable of playing with IrDA, 20 to 60 kHz IR remote control systems, and other less wholesome applications.

Demos are a necessity, but the world seems to have passed over IR in the last decade. That doesn’t mean there still aren’t interesting targets. A week before Shmoocon, [Mike Ossmann] put out the call on Twitter for a traffic light and the associated hardware. Yes, police cars and ambulances use infrared signaling to turn traffic lights green. You shouldn’t. You can, but you shouldn’t.

What was the takeaway from this talk? IR still exists, apparently. Yes, you can use it to send documents directly from your PalmPilot to a laser printer without any wires whatsoever. One of the more interesting applications for IR is an in-car wireless headphone unit that sends something almost, but not quite, like pulse coded audio over infrared. The demo that drew the most applause was an infrared device that changed traffic lights to green. The information to do that is freely available on the web, but you seriously don’t want to attempt that in the wild.

Cordless Drill Uses No Electricity

January 16, 2017 by Manuel Rodriguez-Achach 43 Comments

There are few projects on how to make your own cordless drill, but what sets [Johnnyq90’s] amazing project apart is the fact that his power plant is a nitro engine. Not an easy task of course, but he makes it look easier than it is, and we really enjoyed the construction process.

He uses an RC Kyosho GX12 engine that was previously modified, changing the cooling head with a larger one. The engine drives a gearbox that was taken from another drill. All other parts were hand made. The clutch was carefully machined, and the cooling fan was made in a 3D printer. Other necessary parts were the frame, brass spacers to adjust the engine height and alignment, throttle arm and handle. In the end even the gearbox had to be modified for higher speed. The finished drill sure looks and sounds terrific, and seems to be perfectly capable of doing its job.

As with other mechanical projects from [Johnnyq90], the video has good timing and attention to detail. His channel is definitely worth a visit, specially if you like turbines.

Shmoocon 2017: Dig Out Your Old Brick Phone

January 16, 2017 by Brian Benchoff 37 Comments

The 90s were a wonderful time for portable communications devices. Cell phones had mass, real buttons, and thick batteries – everything you want in next year’s flagship phone. Unfortunately, Zach Morris’ phone hasn’t been able to find a tower for the last decade, but that doesn’t mean these phones are dead. This weekend at Shmoocon, [Brandon Creighton] brought these phones back to life. The Motorola DynaTAC lives again.

[Brandon] has a history of building ad-hoc cell phone networks. A few years ago, he was part of Ninja Tel, the group that set up their own cell phone network at DEF CON. That was a GSM network, and brickphones are so much cooler, so for the last few months he’s set his sights on building out a 1G network. All the code is up on GitHub, and the hardware requirements for building a 1G tower are pretty light; you can roll your own 1G network for about $400.

The first step in building a 1G network, properly referred to as an AMPS network, is simply reading the documentation. The entire spec is only 136 pages, it’s simple enough for a single person to wrap their head around, and the concept of a ‘call’ really doesn’t exist. AMPS looks more like a trunking system, and the voice channels are just FM. All of this info was translated into GNU Radio blocks, and [Brandon] could place a call to an old Motorola flip phone.

As far as hardware is concerned, AMPS is pretty lightweight when compared to the capabilities of modern SDR hardware. The live demo setup used an Ettus Research USRP N210, but this is overkill. These phones operate around 824-849 MHz with minimal bandwidth, so a base station could easily be assembled from a single HackRF and an RTL-SDR dongle.

Yes, the phones are old, but there is one great bonus concerning AMPS. Nobody is really using these frequencies anymore in the US. That’s not to say building your own unlicensed 1G tower in the US is legally permissible, but if nobody reports you, you can probably get away with it.