Simultaneous AP & Client On The Pi Zero W

The Raspberry Pi Zero W is a great platform for IoT projects, with a smattering of GPIO and onboard WiFi. However, security is an important consideration when it comes to the Internet of Things and it can be beneficial to keep your IoT devices on a separate network for safety’s sake. [Albert] wanted to do this all on board the Pi Zero W, and figured out how to get it acting as an access point and a client all at the same time.

[Albert] starts off with a fresh install of Raspbian Stretch, and sets the Pi up in OTG mode. This allows access to the Pi over a USB serial terminal. This is great for productivity when working on headless networking projects, as it can be frustrating trying to work with an SSH session that keeps dropping out when you change settings.

After creating a second named device (ap0) to go along with the one created automatically by the kernal (wlan0), DNSmasq is installed to act as a DHCP server for the AP. Hostapd is then installed to control the AP settings. Following this, like anything in Linux, a flurry of configuration files are edited to get everything humming along and starting up automatically after a reboot. For some reason, things don’t start up smoothly, so [Albert] has a cron job that fires 30 seconds after bootup and toggles the interfaces off and on again, and that’s done the trick.

It’s a useful hack, as it allows the Pi Zero to act as a hub for IoT devices, while also creating a bridge between them and the internet. Traffic can be managed to stop random internet users flicking your lights on and off and overspeeding your dishwasher.

We’ve seen the Pi Zero used for just about everything under the sun so far. If you’re just starting your own IoT build, perhaps you’d like to use the Pi Zero as a streaming camera?

 

Hackaday Prize Entry: Ebers – Diabetes Care, Step By Step

Diabetes is a disease that, among other things, has significant effects on the feet due to a combination of neuropathy, vascular issues, and other factors. You may have seen special diabetes socks with features like non-elasticated cuffs for better circulation and a lack of seams to prevent the formation of blisters. Taking care of  your feet is essential in diabetes to prevent injury and infection. Ebers is a project that seeks to help in just this area.

Ebers monitors plantar pressure, temperature, and humidity in the sole of the shoe. It then feeds this data back to a smartphone for analysis over Bluetooth. The brain of the project is an Arduino Pro Mini which is tasked with interfacing with the various sensors.

The project relies on 3D printed insoles which fit inside the shoe of the wearer. This is a particularly useful application of 3D printing, as it means the insole can be customised to fit the individual, rather than relying on a smaller selection of pre-sized forms. This has the additional benefit of allowing the insole to be designed to minimise pressure on the foot in the first place, further reducing the likelihood of injury and infection. The pressure sensing is actually built into the insole itself, and can measure pressure at several different areas of the foot.

Overall, it’s a project with huge potential health benefits for those with diabetes. We look forward to seeing where this project goes in future, and how it can bring improvements to the quality of life for people the world over.

We’re Using The Word Firmware Wrong

I had an interesting discussion the other day about code written for an embedded system. I was speaking with Voja Antonic about ‘firmware’. The conversation continued forward but I noticed that he was calling it ‘software’. We later discussed it and Voja told me he thought only the parts of the code directly interacting with the microcontroller were firmware; the rest falls under the more generic term of software. It really had me wondering where firmware stops being firmware and is merely software?

The topic has remained on my mind and I finally got around to doing some dictionary searches. I’m surprised that I’ve been using the word differently and I think most of the people I’ve heard use it are doing the same — at least as far as dictionary definitions are concerned. My go to sources are generally Merriam-Webster and Oxford English dictionaries and both indicate that firmware is a type of software that is indelible:

Permanent software programmed into a read-only memory.

computer programs contained permanently in a hardware device (such as a read-only memory)

According to this definition, I have never written a single bit of firmware. Everything I have written has been embedded software. But surely this is a term that must change with the times as technology progress so I kept digging.

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Earth Rovers Explore Our Own Planet

While Mars is currently under close scrutiny by NASA and other space agencies, there is still a lot of exploring to do here on Earth. But if you would like to explore a corner of our own planet in the same way NASA that explores Mars, it’s possible to send your own rover to a place and have it send back pictures and data for you, rather than go there yourself. This is what [Norbert Heinz]’s Earth Explorer robots do, and anyone can drive any of the robots to explore whatever locations they happen to be in.

A major goal of the Earth Explorer robot is to be easy to ship. This is a smaller version of the same problem the Mars rovers have: how to get the most into a robot while having as little mass as possible. The weight is kept to under 500g, and the length, width, and height to no more than 90cm combined. This is easy to do with some toy cars modified to carry a Raspberry Pi, a camera, and some radios and sensors. After that, the robots only need an interesting place to go and an Internet connection to communicate with Mission Control.

[Norbert] is currently looking for volunteers to host some of these robots, so if you’re interested head on over to the project page and get started. If you’d just like to drive the robots, though, you can also get your rover fix there as well. It’s an interesting project that will both get people interested in exploring Earth and in robotics all at the same time. And, if you’d like to take the rover concept beyond simple exploration, there are other machines that can take care of the same planet they explore.

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The Hackers And The Hurricane

When natural disasters strike, particularly if they are in some of the less remote parts of the world, we see them unfolding in real-time on our television screens. They become a 24-hour rolling news exercise in disaster titillation, each fresh horror ghoulishly picked over by breathless reporters live-telecasting from windswept streets, and endlessly rehashed by a succession of in-studio expert guests.

Then once the required image of a dusty child being pulled from the rubble or a tearful mother describing her daughter being swept away is in the can, a politician somewhere is found in bed with a model or a tinpot dictator rattles his sabre, and the world moves on. The BAFTA or the Emmy is a certainty for this one, did you see the anguish!

Meanwhile on the ground, the situation remains the same. There is no power, no sanitation, no communications, no food, and help seems very far away. In the wake of the recent hurricane season across the Caribbean, there are millions of people whose worlds have been wrecked, and several international governments have faced significant criticism for their lethargic response.

In our world of hardware hackers and makers, we are on the whole practical people. We exist to make, and do, rather than to endlessly talk. Seeing the plight of the victims of Irma, Jose, or Maria leaves us wanting to do practical things to help, because that’s what we do. But of course, we can do nothing, because we’re thousands of miles away and probably lack whatever skills or training are in demand on the islands.

It’s heartening then to hear of just a few moments when our wider community has managed to be in the right place at the right time to offer some help. We’ve had a couple in our tips line lately we’d like to share.

[Csp3r] writes about the Derbycon conference held in Louisville, at which [Carlos Perez] and [Jose Quinones Borreros], information security specialists from Puerto Rico, were in attendance. They mentioned a need for emergency radios, and the community at the conference came together to raise money for much more than just a few radios. $15,000 was raised in all, spent on radios, solar chargers, generators, flashlights, USB battery packs, and tools. This amounted to a significant bulk, so Hackers For Charity helped secure some space on an aid flight to the island.

Then [Bruce Perens, K6BP] writes about a request from the American Red Cross to the ARRL for 50 radio amateurs to help with their relief efforts in Puerto Rico. They will perform the role you might expect of enabling essential communications, as well as to quote the ARRL: “help record, enter, and submit disaster-survivor information into the ARC Safe and Well system”. This is a request unprecedented in its scale, and reflects the level of damage across the island.

For most of us, the best we can do when helping out with these events will be to drop coins into an OXFAM or Red Cross collecting tin and leave it to the experts. But as we’ve noted above, for just a few of us the opportunity to do something a bit more useful presents itself. If you find yourself in that position, make it count!

We’ve looked at the role of amateur radio in public service before, and we’ve even featured it in one or two projects. This emergency box for example has all you’d need to provide this type of service.

Cyclone Catarina image from the ISS, [Public domain].

OLED Hacked Power Bank

In a feat of over-engineering, [Everett Bradford] hacked his power bank to add power monitor via an OLED display to show live current, voltage, temperature, and capacity information. The idea came when he learned about the INA219 chip. The INA219 is a current shunt and power monitor IC with an I²C or SMBUS compatible interface. The device is able to monitor both shunt voltage drop and bus supply voltage, with programmable conversion times and filtering. A programmable calibration value, combined with an internal multiplier, enables direct readouts of current in amperes. An additional multiplying register calculates power in watts.

With impressive miniaturization skills, [Everett] dissembles the Xiaomi Mi power bank and manages to add a custom power monitoring module and an OLED display. Not only that, he replaced the 4 LEDs that were the battery level indicators and actually consume more amps than his board plus the display. While active, the board consumes about 8mA. In sleep mode, it consumes less than 30µA.

The 32×64 OLED display and the custom-made circuit was assembled and tightly fitted into the original case. The power bank now gives readings of the battery charge level in a small graph, numeric current input/output, voltage and temperature. The seamless integration of the display into the power bank makes it look like something that could perfectly have come from a store. This is not your typical DIY power bank nor a gigantic 64 cells power bank. It is a precise and careful modification of an existing product, adding value, functionality, and dare I say it, style: an awesome hack!

We can see [Everett] process in the following video:

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Hand-Carving Geometric Art

[Scott Cramer] is a retired professional woodworker who specializes in geometric art made from beautifully joined wood. In this project he’s carving four interlocked cloverleaf rings from a block of basswood. First he made a series of cuts to turn the block into a cuboctahedron, a geometric solid comprising six squares and eight triangles. Then he drew on the basic lines of the rings on the wood and went to work with a chisel, smoothing and separating the rings and carving out the interior. You can see more shots of the project on his Facebook post, which is included after the break.

To see more of [Scott]’s projects you can follow his Twitter feed. Our favorites include this 70″ pentagonal icosatetrahedron built out of hemlock that [Scott] says is the “largest in Coös County, NH” — what, there are others? He also made a magogany representation of a Hamiltonian circuit of a dodecahedron’s vertices.

We love math art on Hackaday — see our interview with Francisco do Comité we ran earlier this year.

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