When [James] moved to Lima, Peru, he brought his jogging habit with him. His morning jaunts to the coast involve crossing a few busy streets that are often occupied by old, smoke-belching diesel trucks. [James] noticed that his throat would tickle a bit when he got back home. A recent study linking air pollution to dementia risk made him wonder how cities could monitor air quality on a street-by-street basis, rather than relying on a few scattered stations. Lima has a lot of taxis, so why wire them up with sensors and monitor the air quality in real-time?
This taxi data logger’s chief purpose is collect airborne particulate counts and illustrate the pollution level with a Google Maps overlay. [James] used a light-scattering particle sensor and a Raspi 3 to send the data to the cloud via Android Things. Since the Pi only has one native UART, [James] used it for the particle sensor and connected the data-heavy GPS module through an FTDI serial adapter. There’s also a GPS to locate the cab and a temperature/humidity/pressure sensor to get a fuller environmental picture.
Take a ride past the break to go on the walk through, and stick around for the testing video if you want to drive around Lima for a bit. Interested in monitoring your own personal air quality? Here’s a DIY version that uses a dust sensor.
Continue reading “Distributed Air Quality Monitoring via Taxi Fleet”
The secret of cold-brew coffee is out. Department stores are selling gimmicks to make it at home or you can make it with a mason jar in good old-fashioned DIY style. This method is for the on-the-go hacker who may not have even the most spartan of equipment to brew a cold cup of Joe. Many hotel rooms are outfitted with a cheap percolating coffee machine and proprietary pods. The pods are just a sachet of filter paper with ground coffee inside.
Leave that percolating fire hazard unplugged and brew those pods overnight in a glass of water. In eight hours, you have a cup of rocket fuel. Compost the spent pod and away you go. Don’t heat your brew in the coffee maker, that’ll probably wreck it. Nuke it if you need it hot.
If coffee implements are your bag, here’s a 3D printed coffee bean grinder but be sure to read up on 3D printing and food safety. If coffee isn’t your cup of tea, how about a perfectly timed cup of tea?
While it is often said that “necessity is the mother of invention”, we can’t say that’s always been our experience here at Hackaday. You won’t need to search too long before you find a project or hack on this site that definitely falls out of the realm of strict necessity. But that’s part of the fun, there’s a reason this site isn’t called AppropriateUseOfTime.com
But when [Sam Storino] couldn’t seem to stop his cats from howling for their supper at 3:00 AM, he had the perfect opportunity to fulfill that age-old wisdom. Not only did he manage to turn a trip to the plumbing isle of his local home improvement store into a very Steampunk-looking automatic cat feeder, but he also found the time to write up an exceptionally detailed series of blog posts on what he learned during the process.
The heart of the machine is everyone’s favorite Linux board, the Raspberry Pi. You might be thinking the Pi is overkill for a simple timer, and you’d be right. Rather than just dump the food out on a set schedule, [Sam] decided to get a little fancy and come up with some Python scripts that will monitor a GMail inbox and activate the feeder hardware when it receives an email with the title “feed cats”. He then uses IFTTT to send the appropriately named email to the GMail account of his cat feeder on a specific schedule. Hey, nobody said necessity was the mother of straightforward invention.
In the final post of the series, [Sam] goes over the hardware side of the device. Copper pipe makes up the frame, which holds a commercial off-the-shelf dry food dispenser. The feeder was designed for manual operation, but by attaching a continuous rotation servo [Sam] can spin it up and dump a pre-measured amount of food via the Pi’s GPIO pins. The addition of some PVC pipe and fittings takes the food and (at least in theory) divides it equally between the two cat bowls below.
If you think [Sam] may have put a bit more thought than was necessary into something as simple as feeding his pets, keep in mind that he’s in exceptionally good company. Paging through the archives, it seems the intersection of felines and hackers is littered with gloriously complex contraptions.
An AT button is a device that helps people with all kinds of physical disabilities to interact with their world. There isn’t much to them, just a switch wired up to a 3.5mm mono plug or jack, but the switch is installed in a large button housing that’s easy to operate.
These buttons can be used with any appliance or toy that can be adapted for mono input. They’re a simple piece of technology that makes a world of difference, but for some reason, they cost around $65 each. Because of this, people make their own simple switches, but these aren’t usually sturdy or long-lasting. [Christopher] thinks they should cost way less than that and set out to make buttons for about $10 in materials. Aside from the printed files, all you really need to make a Clunke button is one Cherry MX in your favorite shade of blue, blue, or blue, and either a 3.5mm mono jack or plug, depending on preference.
[Christopher] and his team devised the Clunke Button in collaboration with the local United Cerebral Palsy chapter as part of their senior design project. When it came time to present the project, they wanted to find a way to be able to pass a Clunke button around the audience and have it do something when pressed. They made an interactive ticker by adding an ESP-01 and a battery. [Christopher] has since taken over the project and continues to improve the design as he progresses through the Prize finals. Code for the ticker is available on GitHub, and the button STL files are on Thingiverse.
[Scott] created an LED candle in preparation for the big mac daddy storm (storms?) coming through. Like millions of other people in Florida, he was stuck at home with his roommates when an oncoming hurricane headed their way. Worrying about blundering about in the dark when the power inevitably went out, they set off to gather up all of the candles they had lying around. Realizing the monstrous pile of candles and matches looked more and more like a death wish, the decision was made to create a makeshift light out of what components they had on hand. Now, not having access to any outside sources for parts means that you are going to have a bare bones model.
That being said, this straightforward light only takes a couple of seconds to put together. Jury rig a couple of AA or AAA batteries up, then slap on a resistor, LED, and jumper to get that sucker running. Wrap electrical tape around the whole thing, or even try duct tape, whatever gets the job done. A little paper hat on top of it will diffuse the light and bada bing, bada boom, you’re all done. Generally though, soldering directly onto a battery is not a wise idea. So, if you want to get fancy, perhaps a better alternative is to have a battery casing as shown below.
This LED candle is a clear option if your home isn’t a micro warehouse for electronic components (apparently it is frowned upon to clog up your garage for projects), and you have limited time. However, if you have a number of extra minutes lying around before your windows blow in, see if you can top the brightest flashlight ever made (thus far). Continue reading “Need a Night-Light?”
Borescope cameras are great inspection tools. They’re flexible, they magnify on a variable scale, and they come with their own lighting. Oh, and they’re pretty cheap, too. Because of all this, these tiny cameras can serve a number of purposes. Doctors put them down your cake hole to look for ulcers and polyps, and mechanics probe pistons with them to check for buildup. [agulesin] used one to make a reading aid for his mom.
Mom suffers from macular degeneration, and can’t read print smaller than 1″ (2.5cm). This condition can cause issues ranging from blurred vision to complete loss of vision in the center of the visual field. Standard handheld magnifiers can work fairly well depending on a person’s condition, but they only provide a fixed magnification level and most offer no lighting.
[Agulesin] had the idea to make a reading magnifier by feeding video from a downward-facing borescope camera to an old netbook. The camera is mounted in a plywood arm that’s fixed to a bi-level platform made from scrap MDF. It’s a simple idea that’s well executed—just project flat, printed material on to a vertical screen. There’s nothing for the user to hold or mount, and no risk of neck strain from looking down over the material.
With any simple project comes limitations. The camera is fixed in place. This rig built to view sheets of A4 paper (between letter and legal size) that are moved around by the user, and it can only handle a stack of so many sheets. If [agulesin]’s mom tried to read a thick novel this way, the camera would likely not focus. Even so, it’s a great piece of assistive tech for people with low vision.
I have storage on the mind, and it comes from two facts in my life:
First, I have tons of stuff in my workshop, far too much for the amount of space I have. A lot of this material is much easier to use if it’s well-organized. Think electronics, robotics, building sets. Modular parts that need to go together a certain way for them to be useful. It is imperative, therefore, that I come up with some sort of organization system to keep the chaos in check.
Second, my favorite tool is the laser cutter, born from my love for building vector designs. I can do art on the computer and have it manufactured in front of my eyes, and share my designs with someone else who can remix it into something even cooler.
So with those two facts in mind, I set about creating a modular storage system in Inkscape and cutting out the design from pine boards using a laser cutter. Let us go on a journey through my thought process:
Continue reading “Modular Storage with Peanut Butter and Lasers”