Too much of a good thing can be a bad thing, and nitrate pollution due to agricultural fertilizer runoff is a major problem for both lakes and coastal waters. Assessing nitrate levels commercially is an expensive process that uses proprietary instruments and toxic reagents such as cadmium. But [Joshua Pearce] has recently developed an open-source photometer for nitrate field measurement that uses an enzyme from spinach and costs a mere $65USD to build.
The device itself is incredibly simple – a 3D printed enclosure houses an LED light source and a light sensor. The sample to be tested is mixed with a commercially available reagent kit based on the enzyme nitrate reductase, resulting in a characteristic color change proportional to the amount of nitrate present. The instrument reads the amount of light absorbed by the sample, and communicates the results to an Android device over a Bluetooth link.
Open-source instruments like this can really open up educational opportunities for STEM groups to get out into the real world and start making measurements that can make a difference. Not only can this enable citizen scientists and activists, but it also opens the door for getting farmers involved in controlling nitrate pollution at its source – knowing when a field has been fertilized enough can save a farmer unnecessary expense and reduce nitrate runoff.
There are a lot of other ways to put an open-source instrument like this to use in biohacking – photometery is a very common measuring modality in the life sciences, after all. We’ve seen similar instruments before, like a DIY spectrophotometer, or this 2015 Hackaday Prize entry medical tricorder with a built-in spectrophotometer. Still, for simplicity of build and potential impact, it’s hard to beat this instrument.
Two tables down from us at SXSW Create the Raspberry Pi foundation had a steady stream of kids playing Minecraft on Raspberry Pi, and picking up paint brushes. The painting activity was driven by a board they spun for the event that used conductive paint to control the Raspberry Pi 2.
The board uses the HAT form factor which it a fancy name for a shield (also a clever one as it stands for “Hardware Attached on Top”). You can see the back side of the board in this image. It utilizes an extremely low-profile surface mount pin socket.
The front side exposes several circular pads of copper which build up a “connect-the-dots” game that is played by painting conductive ink on the surface. This results in an airplane being pained on the board, as well as displayed on the computer. There is a set of pads that allow the user to select what color is painted on the monitor.
We like this as a different approach to education. Kids are more than used to tapping on a touchscreen, clicking a mouse, or pounding a keyboard. But conductive ink provides several learning opportunities; the paint simply connects the inner circle with the outer circle; one of these circles is the same on every single dot (ground); anything that connects these two parts of the dot together will result in input for the computer. Great stuff!
The foundation is taking the boards to Maker Faire Bay Area next month so stop by to see these in action. You can read about the production process for the DOTS board on the Raspberry Pi website. They’re giving away a few boards to software developers who want contribute to the project. And our video interview with [Matt Richardson] is found after the break.
Continue reading “DOTS Uses Paint to Control Raspberry Pi 2”
Tuesday was [Ada Lovelace] day and to recognize it SparkFun posted an article about women in their workforce and the STEM initiative. [Ada Lovelace] is credited with forging a path for women in mathematics and computing. The STEM acronym represents a movement to get more of America’s students into Science, Technology, Engineering, and Mathematics fields in order to keep up with the rest of the developed world. But part of the issue includes drastically increasing the interest of young women in these fields and their access to it. The thing is, I feel the same way about the community at Hackaday.
Obviously some of the biggest names in the hobby electronics and engineering enthusiast industry are women. The name that seems to top lists is always [Limor Fried] who you may know better as [Lady Ada]. She founded Adafruit industries. But there are couple of other notables that stick out in our minds. [Jeri Ellsworth] has been huge name around here forever. Just this week Hackaday was celebrating the Kickstarter for her latest project. [Becky Stern] has had a ton of awesome project featured, mostly in conjunction with her work at Adafruit but her knitting machine hack when she was with MAKE has always stuck out in our minds. And of course, there’s [Quinn Dunki] who has long been building her own 6502 computer from the ground up (Incidentally we’re running a Guest Rant from her at midday on Friday).
What I’m missing is the grass-roots hacks from women. I know they’re out there because I see them at monthly meetings at the local hackerspace. We featured [Caroline’s] bathymetric book, and [Robin]’s collaboration that produced solar powered supercap jewelry. Both are members of Sector67.
So I call for all Hackaday readers to make this a friendly environment for anyone who wants to participate. If you’re a female reader who has been lurking around rather than sending in links to your gnarly hacks please take the plunge and send us a tip! If your female friends have awesome projects, offer to help them document it for a feature. You may not have thought of it, but sharing your projects makes you a role model for young readers.
By trade I’m an orchestra musician — a field that was completely closed off to women until well into the last century. While gender equality hasn’t been reached in all orchestras, the Regional Orchestras I have and do play with, show equal representation of gender throughout. Let’s make the same thing happen with STEM!
The iBeacon has been all over the interwebs lately. Here’s a riff on the Arduino Pro MIni that adds a BLE module. It can be used to make an iBeacon clone. You can also hack a VTag keyfinder to operate in much the same way.
Remember that post about pulling a QR Code generator into Google Docs? One could argue that the best use of this functionality is to add labels to your parts storage that lead back to the product page for the component. [Thanks Nicholas]
[Michael] wrote in to share his crowd funding campaign. He is a school teacher and wants to publish a detective story that gets kids excited about STEM.
Our own [James Hobson] made the first cut to be [Adam Savage’s] new assistant. He’s the [TheHacksmith] (read our staff page if you don’t believe us) and is the third entry featured in this vignette. Apparently they’ve got something against Canadians because they say he’s ineligible due to his nationality!?
If you’ve ever been confused about the features of different Xbee modules this comparison chart may be of assistance.
A couple of weeks ago we learned about a contest put on by TheControllerProject. [TouchStone936] gets credit for quick, easy, and functional. His solution to making shoulder buttons more accessible includes hot-glue, a golf tee, and a binder clip. Pretty clever!
Wanting a better color of backlight for his eReader, [Vivek Gani] cracked it open and applied Kapton Tape as a gel to soften the hue.
And finally something very silly. If you put a strong enough prop on the front, you can get just about anything to fly. This instance involves a flying pizza box which to us looks particularly un-flight-worthy. [via Gizmodo]