Monitor Your City’s Air Quality

July 16, 2017 by 18 Comments

[Radu Motisan]’s entry in the 2017 Hackaday Prize is a series of IoT Air Quality monitors, the City Air Quality project. According to [Radu], air pollution is the single largest environmental cause of premature death in urban Europe and transport is the main source. [Radu] has created a unit that can be deployed throughout a city and has sensors on it to report on the air quality.

The hardware has a laser light scattering sensor for particulate matter and 4 electromechanical sensors for carbon monoxide, nitrogen dioxide, sulfur dioxide and ozone (these sense the six parameters that are recognized as having significant health impact by multiple countries.) These sensors have2-yearear lifespan, so they are installed in sockets for easy replacement, and if needed, you can swap to different sensors to detect different things. The PCBs for the hardware are separated into a WiFi version and a LoRaWAN version and the software runs on an ATMega328 – the PCB has the standard six-pin ISP connection for programming.

The data collected is sent to a server where it is adjusted based on the unit’s calibration parameters and stored in a database per sensor. This makes servicing the sensors at the end of their life easier as all that’s required is replacing the sensors in the unit and changing the calibration parameters stored for that unit, the software changes are required. The server offers the data via a RESTful API so that building dashboards with the stats and charts become easy.

[Radu] used an off the shelf module as the first prototype and attached it to a car while driving around. He used this to test out the plan and work on the server. He then proceeded to designing the PCB hardware and the enclosure for the final unit. This work is an extension of [Radu]’s previous work, spotlit here in the 2015 Hackaday Prize, but also check out this project to put air quality sensors in the classroom.

Continue reading “Monitor Your City’s Air Quality” →

Flush Out Car Thieves With A Key Fob Jammer Locator

July 16, 2017 by 97 Comments

We all do it — park our cars, thumb the lock button on the key fob, and trust that our ride will be there when we get back. But there could be evildoers lurking in that parking lot, preventing you from locking up by using a powerful RF jammer. If you want to be sure your car is safe, you might want to scan the lot with a Raspberry Pi and SDR jammer range finder.

Inspired by a recent post featuring a simple jammer detector, [mikeh69] decide to build something that would provide more directional information. His jammer locator consists of an SDR dongle and a Raspberry Pi. The SDR is set to listen to the band used by key fobs for the continuous, strong emissions you’d expect from a jammer, and the Pi generates a tone that varies relative to signal strength. In theory you could walk through a parking lot until you get the strongest signal and locate the bad guys. We can’t say we’d recommend confronting anyone based on this information, but at least you’d know your car is at risk.

We’d venture a guess that a directional antenna would make the search much easier than the whip shown. In that case, brushing up on Yagi-Uda antenna basics might be a good idea.

Slimline Nixie Clocks

July 16, 2017 by 26 Comments

Everyone needs to build a Nixie clock at some point. It’s a fantastic learning opportunity; not only do you get to play around with high voltages and tooobs, but there’s also the joy of sourcing obsolete components and figuring out the mechanical side of electronic design as well. [wouterdevinck] recently took up the challenge of building a Nixie clock. Instead of building a clock with a huge base, garish RGB LEDs, and other unnecessary accouterments, [wouter] is building a minimalist clock. It’s slimline, and a work of art.

The circuit for this Nixie clock is more or less what you would expect for a neon display project designed in the last few years. The microcontroller is an ATMega328, with a Maxim DS3231 real time clock providing the time. The tubes are standard Russian IN-14 Nixies with two IN-3 neon bulbs for the colons. The drivers are two HV5622 high voltage shift registers, and the power supply is a standard, off-the-shelf DC to DC module that converts 5 V from a USB connector into the 170 V DC the tubes require.

The trick here is the design. The electronics for this clock were designed to fit in a thin base crafted out of sheets of bamboo plywood. The base is a stackup of three 3.2mm thick sheets of plywood and a single 1.6 mm piece that is machined on a small desktop CNC.

Discounting the wristwatch, this is one of the thinnest Nixie clocks we’ve ever seen and looks absolutely fantastic. You can check out the video of the clock in action below, or peruse the circuit design and code for the clock here.

Continue reading “Slimline Nixie Clocks” →

Three Thumbs, Way, Way Up!

July 16, 2017 by 58 Comments

At least one in their lives — or several times a day — everyone has wished they had a third hand to help them with a given task. Adding a mechanical extra arm to one’s outfit is a big step, so it might make sense to smart small, and first add an extra thumb to your hand.

This is not a prosthetic in the traditional sense, but a wearable human augmentation envisioned by [Dani Clode], a master’s student at London’s Royal College of Art. The thumb is 3D-printed out of Ninjaflex and mounted to a printed brace which slides over the hand. One servo rotates the thumb, and a second pulls it closed using a bowden cable system — not unlike that of a bicycle brake. Control of the thumb is achieved by pressure sensors in the wearer’s shoes, linked via Bluetooth to a wristband hosting the servos and the electronics. We already use our hands and feet in conjunction, so why not capitalize on this intuitive link?

Continue reading “Three Thumbs, Way, Way Up!” →

Hey NASA, Do You Want Your Stuff Back?

July 16, 2017 by 53 Comments

What would you do if you found hidden away artifacts of aerospace technology from the Apollo era?

You call NASA.

Two hulking computers — likely necessitating the use of a crane to move them — and hundreds of tape reels were discovered in the basement of a former IBM engineer by their heir and a scrap dealer cleaning out the deceased’s home. Labels are scarce, and those that are marked are mostly from the late 1960s through the mid 1970s, including data from the Pioneer 8 to 11 missions, as well as the Helios missions.

Continue reading “Hey NASA, Do You Want Your Stuff Back?” →

Irising Chicken Coop Door

July 15, 2017 by 26 Comments

What’s cooler than a door that irises open and closed? Not much. They add a nice science-fictiony detail to any entryway. [Zposner]’s dad wanted an automatic door for his chicken coop, so [zposner] took some time and came up with a nice door for him with an iris mechanism. You’ll need to watch the video.

[Zposner] used a combination of laser cutting and a CNC router to cut the pieces, then sanded and painted the wood. After assembly, [zposner] started work on the control mechanism. He’s controlling the door with an Arduino and a motor shield; to let the Arduino know to stop the motor, [zposner] used limit switches which get hit as the mechanism rotates. Once the switches were in the right place and the code written, it was time to finish assembly and install the door on the coop. To keep the Arduino that safe, it was installed in a plastic container with a screw lid, and then hot-glued to beside the iris.

Unfortunately, chickens don’t necessarily care how cool something is, and in this case, they didn’t realize that the iris was a door – they refused to exit the coop through it. [Zposner] tried a few things before settling on putting the chicken on the edge of the door – then the chicken would realize that it could go through it.

[Zposner]’s dad now has a snazzy door that opens with a switch. It was a great project for [zposner] and his dad to work on and, even if the chickens seem unimpressed, they did a great job. Check out the iris porthole that a Detroit Hackerspace built into its door, or, if you really want to build an iris mechanism, but don’t have access to a CNC router, a laser cutter, or, you know, wood, you could build this out of bits you have lying around.

Continue reading “Irising Chicken Coop Door” →

The Sound Of (Synthesized) Music

July 15, 2017 by 7 Comments

What’s an ADSR envelope generator? If you are a big music hacker, you probably know. If you are like the rest of us, you might need to read [Mich’s] post to find out that it is an attack-decay-sustain-release (ADSR) envelope generator. Still confused? It is a circuit used in music synthesis. You can see a demo of the device in the video below.

Before the Altair–which was sort of the first hobbyist computer you could actually buy–electronics magazines were full of music synthesizer projects that had a lot in common with the analog computers of old. A lot of people took that very seriously and then computers took over the collective consciousness and we found musical hackers started working with (digital) computer-based synthesizers. But the old analog synth designs just won’t die. [Mich’s] ADSR is based on an ancient design, and the amount of information and additions he provides makes it worth a read, even if you don’t fancy building one.

Continue reading “The Sound Of (Synthesized) Music” →