Small Swedish Stores Are Miniature Oases In A National Food Desert

It all started one night in 2016 after [Robert Ilijason] dropped the last remaining jar of baby food in the house, breaking it. On the 20-minute drive to the nearest supermarket, he had an idea: what if there were small, 24-hour convenience-level grocery stores that could fill the glaring need for access to basics across the country?

Sweden has lost a few thousand smaller grocery stores in the last 25 years or so, mostly in rural areas. For many people living outside the cities, the nearest place to buy milk is several miles away, at a huge supermarket that’s either in a city, or close to it. After [Robert] built Sweden’s first 24-hour unmanned convenience store, the idea received quite a bit of media attention.

Five years and a pandemic later, the concept is still going strong. A chain of 30 of these bite-sized bodegas have popped up all over Sweden, run by a company called Lifvs. They have no staff at all, not even a cashier. Instead, shoppers unlock the door with their phones. They scan all their barcodes into an app, which provides a bill every month and is linked to both their bank account and national identity system. Beyond that, security is in the form of a single camera.

Because these tiny stores are staff-less, the prices can be kept relatively low. The only problem is that the technology is a bit of an issue for some older residents. Back in 2016, [Robert Ilijason] was trying to figure out another way for customers to unlock the door, but it doesn’t look like Lifvs has solved that problem yet.

One thing you can’t complain about with a store like this is the selection. We have to wonder if shoppers are more or less likely to encounter fasciated fruit amongst the produce.

Spherical Keyboard Build Leaves Hacker Well-Rounded

Often times we as hackers don’t know what we’re doing, and we sally forth and do it anyway. Here at Hackaday, we think that’s one of the best ways to go about a new project, and the absolute fastest way to learn a whole lot as you go. Just ask [Aaron Rasmussen] regarding this spherical, standing 5×6 dactyl manuform keyboard build, which you can see in a three-part short video series embedded after the break.

[Aaron] gets right down to it in the first video. He had to get creative right away, slicing up the dactyl manuform model to fit on a tiny print bed. However, there’s plenty of room inside the sphere for all that wiring and a pair of Elite-C microcontrollers running QMK. Be sure to turn on the sound to hear the accompanying voice-overs.

The second video answers our burning question: how exactly does one angle grind a slippery sphere without sacrificing sheen or shine? We love the solution, which involves swaddling the thing in duct tape and foam.

You may be wondering how [Aaron] is gonna use any kind of mouse while standing there at the pedestal keyboard. While there is space for a mouse to balance on top, this question is answered in the third video, where [Aaron] learns the truth behind the iconic ThinkPad nubbin and applies this knowledge to build a force-feedback joystick/trackpoint mouse. Awesome answer, [Aaron]!

Not ready to go full-tilt, sci-fi prop ergo? Dip your toe in the DIY waters with a handy macropad.

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Automated Watering Machine Has What Plants Crave: Fertilizer

We’ve seen countless automated plant care systems over the years, but for some reason they almost never involve the secret sauce of gardening — fertilizer. But [xythobuz] knows what’s up. When they moved into their new flat by themselves, it was time to spread out and start growing some plants on the balcony. Before long, the garden was big enough to warrant an automated system for watering and fertilizing.

This clever DIY system is based around a 5L gravity-fed water tank with solenoid control and three [jugs] of liquid fertilizer that is added to the water via peristaltic pump. Don’t worry, the water tank has float switches, and [xythobuz] is there to switch it off manually every time so it doesn’t flood the flat.

On the UI side, an Arduino Nano clone is running the show, providing the LCD output and handling the keypad input. The machine itself is controlled with an ESP32 and a pair of four-channel relay boards that control the inlet valve, the four outlet valves, and the three peristaltic pumps that squirt out the fertilizer. The ESP also serves up a web interface that mimics the control panel and adds in the debug logs. These two boards communicate using I²C over DB-9, because that’s probably what [xythobuz] had lying around. Check out the demo video after the break, and then go check on your own plants. They miss you!

Don’t want to buy just any old peristaltic pumps? Maybe you could print your own.

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The Coffee Must Flow: Replacing A Spent Lithium Cell In A Coffee Machine

When [hacky] bought a used Douwe Egberts Gallery 200 all-in-one coffee maker, the machine was known to have a ’empty battery’. Being one of those fancy coffee makers that handle everything from the grinding of coffee beans to the application of hot water and steam, it relies on instructions for each coffee recipe. Unfortunately, it turns out that this machine stores these on battery-backed SRAM, as [hacky] found out with help from friendly folk over at the Dutch Tweakers forum.

The Douwe Egberts Gallery 200 is a rebranded machine that’s also sold in Scandinavia as the Wittenborg FB 5100. These machines have an ST M48T58 TimeKeeper module that combines 8 kB of persistent SRAM with a real-time clock. Being powered from a single coin cell (lithium carbon monofluoride chemistry), their lifespan is limited.

Replacing the coin cell in an M48T58 TimeKeeper module with AA cells.

Fortunatley, a DE-9 connector is provided on the back to provide service/maintenance access to to the hardware. Using a conveniently available programming guide for the hardware, it was easy to figure out the pinout and baud rate (9600, 8 bit, ignore parity, no flow control). This allows for reprogramming the SRAM, but without replacing the battery this data would be gone again on the next start.

Based on the ST M48T58 datasheet, it’s not clear that the clip-on module containing the coin cell and crystal can be replaced, though one could simply plug in a new M48T58 module. Or, as [hacky] did, it’s also possible to cut open the ‘SNAPHAT’ top section and wire in a replacement battery module. With two 1.5V AA cells providing the 3V to the module, it was operational again.

Next up: working out what to write to the SRAM to make the coffee flow again.

Mobile Electronics Workstation Has It All In A Small Package

Home is absolutely everything these days. Plenty of spaces around the abode have had to do double and triple duty as we navigate work, play, and everything in between. Although it’s been a great time to engage in hobbies and even find new ones, where exactly are we supposed put all the stuff that accumulates?

[Fabse89] needed a portable, usable solution for doing electronics work that could be easily packed away. They happened upon a tool case being thrown out, and repurposed it into a great one-stop solution for whenever the urge to play with pixies strikes.

[Fabse89] started by stripping the box out to the bare walls and modeling the inside in Fusion360. Then they built and cut an acrylic insert that holds two power supplies and a soldering station. There are fixed 5 V and 12 V outputs on one power supply, plus a variable supply that maxes out at 48 V.

When it came to tool storage options, [Fabse89] got lucky with a small, seldom-used set of plastic drawers that fits perfectly next to the power station. These hold all the small tools like flush cutters, pliers, and a de-soldering pump. The top section of the case folds back and is the perfect place for component storage boxes. We think this is a tidy solution and especially like that you don’t have to dismantle it to use it — can be used with everything in place and packed up quickly. We also like that the front lid pulls down into a makeshift table, so this really could go anywhere with mains power.

Acrylic not rugged enough for your tastes? Here’s a DIY supply that doubles as a melee weapon.

MIT’s Hair-Brushing Robot Untangles Difficult Robotics Problem

Whether you care to admit it or not, hair is important to self-image, and not being able to deal with it yourself feels like a real loss of independence. To help people with limited mobility, researchers at MIT CSAIL have created a hair-brushing robot that combines a camera with force feedback and closed-loop control to adjust to any hair type from straight to curly on the fly. They achieved this by examining hair as double helices of soft fibers and developed a mathematical model to untangle them much like a human would — by working from the bottom up.

It may look like a hairbrush strapped to a robot arm, but there’s more to it than that. Before it ever starts brushing, the robot’s camera takes a picture that gets cropped down to a rectangle of pure hair data. This image is converted to grayscale, and then the program analyzes the x/y image gradients. The straighter the hair, the more edges it has in the x-direction, whereas curly hair is more evenly distributed. Finally, the program computes the ratio of straightness to curliness, and uses this number to set the pain threshold.

The brush is equipped with sensors that measure the forces being exerted on the hair and scalp as it’s being brushed, and compares this input to a baseline established by a human who used it to brush their own hair. We think it would be awesome if the robot could grasp the section of hair first so the person can’t feel the pull against their scalp, and start by brushing out the ends before brushing from the scalp down, but we admit that would be asking a lot. Maybe they could get it to respond to exclamations like ‘ow’ and ‘ouch’. Human trials are still in the works. For now, watch it gently brush out various wigs after the break.

Even though we have wavy hair that tangles quite easily, we would probably let this robot brush our hair. But this haircut robot? We’re not that brave.

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