DIY Filtered Positive Pressure Suit Shows Fine Workmanship

July 3, 2020 by Donald Papp 19 Comments

[Andrew]’s Air filtering unit & positive pressure supply might look like something off the set of Ghostbusters, but it’s an experiment in making a makeshift (but feasible) positive pressure suit. The idea is to provide an excess of filtered air to what is essentially an inflatable soft helmet. The wearer can breathe filtered air while the positive pressure means nothing else gets in. It’s definitely an involved build that uses some specific hardware he had on hand, but the workmanship is great and shows some thoughtful design elements.

The unit has three stacked filters that can be easily swapped. The first stage is medical mask material, intended to catch most large particles, which is supported by a honeycomb frame. The next filter is an off-the-shelf HEPA filter sealed with a gasket; these are available in a wide variety of sizes and shapes so [Andrew] selected one that was a good fit. The third and final stage is an activated carbon filter that, like the first stage, is supported by a honeycomb frame. The idea is that air that makes it through all three filters is safe (or at least safer) to breathe. There isn’t any need for the helmet part to be leakproof, because the positive pressure relative to the environment means nothing gets in.

Air is sucked through the filters and moved to the helmet by an HP BLc7000 server fan unit, which he had on hand but are also readily available on eBay. These fan units are capable of shoveling a surprising amount of air, if one doesn’t mind a surprising amount of noise in the process, so while stacked filter stages certainly impede airflow, the fan unit handles it easily. The BLc7000 isn’t a simple DC motor and requires a driver, so for reference [Andrew] has a short YouTube video of how the fan works and acts.

All the 3D models and design files are available online should anyone wish to take a closer look. It’s certainly a neat experiment in making a filtered positive pressure supply and head cover with materials that are fairly common. If [Andrew] ever wants to move to a whole-body suit, maybe repurpose an old Halloween costume into a serviceable positive pressure suit.

An Off-The-Grid Instant Messaging Plattform

July 2, 2020 by Moritz v. Sivers 19 Comments

Having an open-source communication device that is independent of any network and works without fees sounds like a hacker’s dream come true. Well, this is exactly what [bobricius]’ is aiming at with his Armawatch and Armachat devices.

Recently, [bobricius] built a LoRa based instant messaging device named Armachat. The gadget is controlled by a SAMD21 MCU with native USB and includes a QWERTY keyboard and an LCD display. Communication is based on an RFM95 LoRa transceiver which can reach a range of up to 2 km under ideal conditions. [bobricius] is a wiz when it comes to PCB design and one thing that makes his projects look so good is how he often uses PCBs as enclosures.

Armachat came in two form factors a large desktop and a smaller pocket version. The new Armawatch is another downsized version that perfectly fits on your arm by using a smaller display and keyboard. [bobricius] also did a lot of work on the firmware which now features a message delivery confirmation and the possibility to automatically resend undelivered messages. Future improvements will include message encryption, a store-and-forward function, and GPS position parsing. [bobricius] is also working on completing his portfolio of communicators with a credit-card-sized version.

LoRa is the go-to technology for off-the-grid communication devices and there are already other ongoing projects for using it to construct a mesh network.

Wearable Device For Preventing SUDEP (Sudden Unexpected Death In Epilepsy)

June 22, 2020 by Orlando Hoilett 13 Comments

Epilepsy is a neurological disorder characterized by the occurrence of seizures. Epilepsy can often prevent patients from living a normal life since it’s nearly impossible to predict when a seizure will occur. The unpredictability of the seizures makes performing tasks such as driving extremely dangerous. One of the challenges in treating epilepsy is the condition is still not very well understood.

Neurava, a recent startup company from Purdue University, aims to change this fact. Neurava is developing a neck wearable that “records key biological signals related to epilepsy.” None of the press releases we’ve found so far elaborate on what those biological signals are. Though we have some guesses of our own, we’ll leave it to the Hackaday community to speculate for the time being. One of the major hurdles in using biological signals to treat conditions like epilepsy both lies in the accuracy of the measurement itself in addition to how well the measurement correlates to the underlying condition. From the looks of it, Neurava has been working on this technology for a long time and are certainly more aware of these challenges than we are.

Neurava’s wearable includes a few other functionalities we’ve come to expect in this era of smart devices such as wireless data transmission to both the physician and patient, physician dashboard to monitor the patient’s progress over extended periods of time, and in-time alerts in the event a seizure is detected.

Neurava appears to have garnered a bit of publicity in these last few months and are currently securing seed money to help advance their technology. We’ll check in every so often to see how they’re doing.

Surviving The Pandemic As A Hacker: Peering Behind The Mask

June 3, 2020 by Jenny List 30 Comments

We’re now several months into the global response to the COVID-19 pandemic, with most parts of the world falling somewhere on the lockdown/social distancing/opening up path.

It’s fair to say now that while the medical emergency has not passed, the level of knowledge about it has changed significantly. When communities were fighting to slow the initial spead, the focus was on solving the problem of medical protection gear and other equipment shortages at all costs with some interesting yet possibly hazardous solutions. Now the focus has moved towards protecting the general public when they do need to venture out, and as society learns to get life moving again with safety measures in place.

So, we all need masks of some sort. What type to do you need? Is one type better than another? And how do we all get them when everyone suddenly needs what was once a somewhat niche item?

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Arduband Gives Your Eyes A Hand

May 24, 2020 by Kristina Panos 14 Comments

Let’s face it, we probably all sit at our computers for way too long without getting up. Yes, there’s work to be done, games to be played, and the internet abounds with people who are wrong and must be down-voted and/or corrected. We totally get and respect all that. However, if you want to maintain your middle- and long-range vision, you should really get up regularly and gaze out the window for a bit.

In fact, the Arduband does you one better. Its Arduino Nano and accelerometer check your position every ten minutes. If you haven’t changed your Z by the third check, then it’s time for a break. The combination of an RGB LED, buzzer, and vibrating disc motor working together should be enough to pull you out of any computerized stupor, and they won’t give up and go back to sleep until you have stood up and remained upright for one minute.

We like that [ardutronics123] spun up a board and made it small enough to be wrist-mounted using a watch strap. It would work just as well worn around your neck, and would probably even fit in your pocket. Blink a few times before you check out the build video after the break.

Arduband would be great on the go, but who does that anymore? If you spend every day at the same desk, you could point a time-of-flight sensor at your chair and start a timer.

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Dyeing Fabric To Create Sensors

May 22, 2020 by Danie Conradie 21 Comments

Fabrics with electrical functionality have been around for several years, but are very rarely used in mainstream clothing. The fabrics are very expensive and the supply can be unreliable. Frustrated by this, [Counter Chemists] developed PolySense, simple open-source technology to make any fibrous material into a conductive material that can be used to sense pressure, stretch, capacitive touch, humidity, or temperature.

PolySense uses a process called in-situ polymerization, effectively dying a fabric to become piezoelectric. This is done by first soaking the fabric in a mixture of water and the organic compound pyrrole, and then adding iron chloride to trigger a reaction. The polymerization process that takes place wraps the individual fibers of the fabric in conductive polymer chains.

Instead of just uniformly coating a fabric, various masking techniques can be used to dye patterns onto the fabric for various use cases. The video after the break shows a range of these applications, including using polymerized gloves and leggings for motion capture, a zipper that acts like a linear potentiometer, and touch-sensitive fabric. The project page lists sources for the required chemicals in both Europe and the US, and we look forward to seeing what other applications the community can come up with.

The project is very well documented, with a number of scientific papers covering all the details. [Counter Chemists] will also be presenting PolySense at the 2020 Virtual Maker Faire.

This technology can also be used to make a fabric piano with a lot less effort. On the more mechanical side of things, you can also 3D print on pre-stretched fabric to make it pop into 3D shapes.

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Is That An ESP32 On Your Wrist?

May 22, 2020 by Al Williams 38 Comments

What could you do with a dual-core 240 MHz ESP32 that supports Arduino-style programming, with 16 MB of flash, 8 MB of PSRAM, and 520 k of RAM? Oh, let’s throw in a touchscreen, an accelerometer, Wifi, and Bluetooth. Besides that, it fits on your wrist and can show the time? That’s the proposition behind Lilygo T Watch 2020. If it sounds like a smartwatch, it is. At around $25 –and you can snag the hardware from a few different places — it is not only cheaper than the latest flagship smartwatch, but it is also infinitely more hackable.

OK, so the screen is only 1.54″, but then again, it is a watch. If Arduino isn’t your thing, you can use anything else that supports the ESP32 like Micropython or even Scratch. There are variants that have LoRA and GPS, at slightly higher prices. You can also find ones with heart rate monitors and other features.

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