Tracking Cicadas With Radiolab And An Arduino

Cicadia

Once every 17 years, a population of cicadas ranging from Connecticut to the Appalachian highlands of North Carolina emerges to annoy everyone within earshot. The last time east coasters saw this brood was in 1996, making 2013 yet another year of annoying insect pests. The only question is, when will we start to see this year’s cicada brood?

Radiolab, the awesome podcast and public radio show, has put together an awesome project that asks listeners to track when the cicadas in their area will emerge. Cicadas generally enter their loud and obnoxious adult stage when the ground temperature 8 inches below the surface reaches 64º F. Armed with an Arduino, thermistor, and a few wires and resistors, any Radiolab listener can upload soil temperature data to Radiolab servers where all the data will be correlated with documented cicada sightings.

After following the page’s instructions for wiring up a bunch of LEDs and a thermistor to an Arduino, just upload the most well-commented code we’ve ever seen and go outside to take soil temperature measurements. The temperature is displayed in a pseudo-binary format on nine LEDs. To decode the temperature without counting by powers of two, Radiolab has an online decoder that also allows you to upload your data and location.

Scooterputer, The All-in-one Scooter Computer

ScootDisplay-2

We’ve seen a fair share of carputer builds involving a Raspberry Pi in the last few months, but even the power of a Raspi can’t compete with the awesomeness of this Arduino-powered scooterputer.

Like all awesome projects, this build is the product of a massive case of feature creep. Initially, [Kurt] only wanted a voltage monitor for his battery. With an  Arduino Duemilanove, a voltage divider, and an evening of coding, [Kurt] whipped up a simple device with three LEDs to indicate the status of the batter: either low, good, or charging.

The project was complete until he ran across an awesome OLED screen. Using a touch screen display for just battery monitoring is a bit overkill, so [Kurt] made a trip over to Sparkfun and got his hands on a temperature sensor, real-time clock, accelerometer, GPS sensor, and even a cellular shield.

The resulting scooterputer is a masterpiece of in-vehicle displays: there’s a digital speedometer and GPS unit, and the cellular shield works as a tracking device and a way to download real-time maps of the scooter’s current location with itouchmap.

While the majority of the electronics are hidden under the hood of the scooter, the display of course needed to be out in the weather. To do this, [Kurt] found a nice enclosure with a rubber boot that perfectly fit the OLED display. The display is connected to the Arduino with a cat5 cable, and everything should hold up pretty well as long as [Kurt] doesn’t drive through a hurricane.

You can check out a video of the scooterputuer below.

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Automated Cat Feeder And Large Plastic Screws

We’ve seen automated food dispensers for pets, but none that go so far as to build large plastic screws for dispensing kibble.

This isn’t [Mathieu]’s first automatic cat feeder; an earlier version used a wheel to dispense cat food in excessively large version. To improve upon his first build, [Mathiu] decided to use an Archimedean screw to dispense food in 5 gram increments. There was a problem, though: a proper industrial screw cost about $1500 and the ‘consumer’ versions of what he wanted were trash. He though about casting one in epoxy but didn’t want to poison his cat with strange chemicals. He ended up using PolyMorph for his screw, a plastic that melts at 60º C and is also used in medical devices.

The electronics of the build are an Arduino, a  DS1307 real-time clock, LCD display, and a relay board powering an electric screwdriver motor. From the video demo below, we’re going to say [Mathieu] put together a pretty nice automated cat feeder.

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Update: Grow Controller Rebuilt To Last

new-grow-controller

[The Cheap Vegetable Gardener] assembled his first grow controller about three and a half years ago. He’s been very happy with it and knows that he’ll be using it for years, maybe even decades to come. He just finished overhauling the grow controller design to help make sure he doesn’t burn down his garage one day. You have to admit, without knowing anything about the project this rendition does look safer than his original offering.

Pictured above is the weather-proof enclosure he used to house four mains-rated solid state relays. This box is isolated from the control hardware, providing heavy-duty utility plugs to interface with the heater, lights, fan, and water pump.  He mounted the Arduino board which controls the relays to the outside of the box, using the Ethernet wire to switch the SSRs. It uses a manufactured shield he designed which will help ease the pain of fixing the system if parts ever go bad.

Later on in the build he shows the grow light and heaters used in his operation. The heaters simply screw into light sockets; something we’ve never come across before.

Measuring The Lifespan Of LEGO

lifespan-of-LEGO

How many times can you put two LEGO pieces together and take them apart again before they wear out? The answer is 37,112. At least that’s the number established by one test case. [Phillipe Cantin] was interested in this peculiar question so he built the test rig above to measure a LEGO’s lifespan.

The hacked together apparatus is pretty ingenious. It uses two servo motors for testing, each driven by the Arduino which is logging the count on an SD card. One of the two white LEGO parts has been screwed onto an arm of the upper servo. That servo presses down onto the mating piece which is sitting inside that yellow band. Look close and you’ll realize the yellow is the handle end of an IC puller. When the post on the lower servo is moved toward one arm of the puller it grips the lower LEGO piece tightly so that the upper servo can pull the two apart. In addition to the assembly and disassembly step there’s a verification step which raises the mated parts so that a reflectance sensor can verify that they’re holding together. [Phillipe] let the rig run for ten days straight before the pieces failed.

Don’t miss his video description of the project after the break.

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Rolling Your Own Minimal USB To Serial Arduino Programmer

usb-to-serial-programmer

[Hans Peter] wanted to move away from using full Arduino boards in his projects. One of the components he rarely used after the development stage is the USB hardware. Once the firmware is flashed to the chip he didn’t need it any longer. So he tried his hand with some really small SMD parts by building this USB to serial Arduino programmer.

The chip he went with isn’t the FTDI part we’re used to. Instead of using an FT232RL, he opted for its smaller cousin the FT230x. This chip doesn’t fully implement the communications protocol of the 232, but it does work with AVRdude and that’s all that really matters. Above you can see [Hans’] creation next to the official Arduino USB-to-serial programmer. He used the same connection scheme, but went with an edge connector for the USB instead of using a mini-B jack.

It’s pretty impressive to see his prototyping work with the 16-pin QFN package. He soldered it dead-bug style to a couple of SIL pin headers in order to test it on a breadboard. The first board he assembled was too loose in the USB port, but he added some tape to the back to make it thicker, and coated the edge connector traces with a bit of solder and that did the trick.

Home Security Hardware Makes You The Monitoring Service

diy-home-security

[Nick] and [Simon] both have home security systems with a monitoring service who will call whenever an alarm is tripped. For [Simon] this ends up happening a lot and he wanted to change the circumstances that would trigger a call. Because of company policy the service is inflexible, so he and [Nick] went to work cutting them out of the loop. What they came up with is this custom electronics board which monitors the security system and calls or texts them accordingly.

They started with the self-monitoring alarm system design we looked at back in September. This led to the inclusion of the SIM900 GSM modem, which is a really cheap way to get your device connected to the cellular network. It also uses a DTMF touch tone decoder to emulate the phone line to keep the security system happy. [Simon] highlights several changes he made to the design, as well as the reasons for them. One idea he has for a possible revision is to do away with the MT8870 chip which handles the touch tones. He thinks it may be possible to use the SIM900’s DTMF features to do that work instead.