Wireless Data Connections Through Light

When wired networking or data connections can’t be made, for reasons of distance or practicality, various wireless protocols are available to us. Wi-Fi is among the most common, at least as far as networking personal computers is concerned, but other methods such as LoRa or Zigbee are available when data rates are low and distances great. All of these methods share one thing in common, though: their use of radio waves to send data. Using other parts of the electromagnetic spectrum is not out of the question, though, and [mircemk] demonstrates using light as the medium instead of radio.

Although this isn’t a new technology (“Li-Fi” was first introduced in 2011) it’s not one that we see often. It does have a few benefits though, including high rates of data transmission. In this system, [mircemk] is using an LED to send the information and a solar cell as the receiver. The LED is connected to a simple analog modulator circuit, which takes an audio signal as its input and sends the data to the light. The solar cell sends its data, with the help of a capacitor, straight to the aux input on a radio which is used to convert the signal back to audio.

Some of the other perks of a system like this are seen here as well. The audio is clear even as the light source and solar cell are separated at a fairly significant distance, perhaps ten meters or so. This might not seem like a lot compared to Wi-Fi, but another perk shown is that this method can be used within existing lighting systems since the modulation is not detectable by the human eye. Outside of a home or office setting, systems like these can also be used to send data much greater distances as well, as long as the LED is replaced with a laser.

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Open Source OLED Nametag Is Full Of Features

Ever wanted a sweet OLED nametag with fancy features like daylight readability, automatic brightness adjustment, GIF animation support, all-day runtime, easy web interface, and more? [TobleMiner]’s OLED Nametag is the project you want to keep an eye on in that case.

It’s still an early prototype, but the feature list looks great and works with a variety of OLED modules that are easily available. The enclosure can be 3D printed, and while there is very little spare room inside the housing, [TobleMiner] has clearly made the most of all available space. Some PCB fab houses offer component placement these days, and the board is designed with exactly that in mind.

We’ve seen a batteryless E-paper display make a serviceable nametag in the past, and while those offer high contrast and wide viewing angles, they lack the sort of features this project is bursting at the seams with. Affordable access to good components and the ability to have high-quality PCBs made on demand has really raised the bar in terms of what a hacker project can work with in recent years, and we love to see it expressed in projects like this one.

Souped-Up Reflective Sensor Uses Itself For Wireless Programming

Proximity sensors are common enough in automation projects that we hardly give them a second thought — pick something with specs that match the job and move on. But they can be fussy to get adjusted just right, a job made more difficult if they’re located in some out-of-the-way corner.

But where lies a challenge, there’s also an opportunity, as [Ido Gendel] shows us with this remote-controlled proximity sensor. The story behind this clever little hack starts with an off-the-shelf sensor, the kind with an IR LED and a phototransistor pointed in the same direction that gives a digital output when the light bouncing back into the phototransistor exceeds a certain threshold. It was setting the threshold that gave [Ido]’s client trouble, so [Ido] decided to build a programmable drop-in replacement to make the job easier.

The first try at this used an OBP732 reflective transmitter and an ATtiny202 microcontroller and had three pads on the PCB for programming. This still required physical contact for programming, though, so [Ido] had the idea to use the sensor for wireless IR programming. The microcontroller on version two was switched to an ATtiny212, and a couple of components were added to control the power of the LED so the sensor could do double duty. A programmer using the same sensor and a USB-to-UART adapter completes the system, and allows the sensor threshold to be set just by shining the programmer in its general direction from up to 25 cm away.

We think that getting multiple uses from a single sensor is pretty clever, so hats off for this one. It’s not the first time we’ve featured one of [Ido]’s projects, but it’s been quite a while — this one-clock-cycle-a-day Shabbat clock was the most recent, but you can clearly see the roots of the sensor project in this mouse pointer data encoder that goes all the way back to 2015.

Headset’s Poor Range Fixed By Replacing Antenna

[rafii6312]’s Corsair HS80 wireless headset had a big problem: short range. The sound quality was great, but the wireless range wasn’t winning any friends. Fortunately, the solution was just to swap the small SMT antenna on the USB transmitter for an external one.

Original SMT antenna (blue component) offers small size, but poor range.

This particular headset relies on a USB dongle to transmit audio from PC to headset over its own 2.4 GHz wireless connection. By popping open the USB dongle, [rafii6312] was able to identify an SMT antenna and easily desolder it, replacing it with a wired connection to a spare 2.4 GHz external antenna. That’s all it took to boost the headset’s range from barely one room to easily three rooms, which is a success by any measure.

Sadly, the USB transmitter dongle doesn’t have any intention of being opened and puts up a fight, so the process was a bit destructive. No problem, [rafii6312] simply fired up Fusion360 to design a new 3D-printed enclosure that accommodated the new antenna. Pictures, instructions, and 3D model files are all available on the project page, if you want to improve your headset, too.

This kind of antenna upgrade is reasonably straightforward, but if one is armed with the right knowledge, antenna upgrades from scratch using scrap wire and dollar store hardware are entirely possible. Just be sure to pick an antenna that doesn’t weigh down your headset.

Hackaday Prize 2023: Bolt Bot Micro Servo Droids

This Hackaday prize entry from [saul] is the beginning of a reconfigurable kit of 3D printed parts and servo motors for robotics learning. With just access to a printer, a few cheap-as-chips servo motors, an Arduino, and some nuts and bolts, you could be hacking together robot walkers within a few hours of starting!

Bolt Bots is very simple to understand, with all the mechanics and wiring out there in the breeze, but strictly for indoor use we reckon. If you want to add remote control to your application, then drop in one of the ubiquitous nRF24L01 boards and build yourself a copy of the remote control [saul] handily provides in this other project.

There really isn’t a great deal we can say about this, as it’s essentially a build kit with quite a few configuration options, and you just have to build with it and see what’s possible. We expect the number of parts to proliferate over time giving even more options. So far [saul] demonstrates a few flavors of ‘walkers’, a rudimentary ‘robot arm’, and even a hanging drawbot.

The bolt hardware can be found in this GitHub repo, and the remote control code in this second one.

Servo-based designs are sometimes sneered at due to their dubious accuracy and repeatability, but with a little of effort, this can be vastly improved upon. Also, multi-legged walkers need multiple servos and controllers to drive ’em. Or do they?

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Wireless Charging On A Massive Scale

Despite the increasing popularity of various electric vehicles, the limits of battery technology continue to be a bottleneck in their day-to-day use. They don’t behave well in extreme temperatures, they can wear out quickly, and, perhaps most obviously, charging them is often burdensome. Larger batteries take longer to charge, and this can take a lot of time and space, but this research team from Chalmers University are looking to make this process just a little bit easier.

The group has been developing an inductive wireless charging method for large vehicles including cars, trucks, busses, and ferries that can deliver 500 kW across a 15 cm (6 inch) air gap. The system relies on a silicon carbide semiconductor and extremely thin copper wire in order to make all this happen, and eliminates the need for any human involvement in the charging process. This might not be too much of a hassle for plugging in an electric car, but for larger vehicles like busses and ferries traditional charging methods often require a robot arm or human to attach the charging cables.

While this technology won’t decrease the amount of time it takes batteries to charge, it will improve the usability of devices like these. Even for cars, this could mean simply pulling into a parking space and getting the car’s battery topped off automatically. For all the talk about charging times of batteries, there is another problem looming which is that plenty of charging methods are proprietary as well. This charger attempts to develop an open-source standard instead.

Thanks to [Ben] for the tip!

Security Vulnerabilities In Modern Cars Somehow Not Surprising

As the saying goes, there’s no lock that can’t be picked, much like there’s no networked computer that can’t be accessed. It’s usually a continual arms race between attackers and defenders — but for some modern passenger vehicles, which are essentially highly mobile computers now, the defenders seem to be asleep at the wheel. The computing systems that control these cars can be relatively easy to break into thanks to manufacturers’ insistence on using wireless technology to unlock or activate them.

This particular vulnerability involves the use of a piece of software called gattacker which exploits vulnerabilities in Bluetooth Low Energy (BLE), a common protocol not only for IoT devices but also to interface a driver’s smartphone or other wireless key with the vehicle’s security system. By using a man-in-the-middle attack the protocol between the phone and the car can be duplicated and the doors unlocked. Not only that, but this can be done without being physically close to the car as long as a network of some sort is available.

[Kevin2600] successfully performed these attacks on a Tesla Model 3 and a few other vehicles using the seven-year-old gattacker software and methods first discovered by security researcher [Martin Herfurt]. Some other vehicles seem to have patched these vulnerabilities as well, and [Kevin2600] didn’t have universal success with every vehicle, but it does remind us of some other vehicle-based attacks we’ve seen before.