Temperature Logging On The Last Frontier

August 22, 2019 by Kristina Panos 36 Comments

In Alaska, the impact of climate change is easy to see. Already the melting permafrost is shifting foundations and rocking roads. Hotter summers are also turning food caches from refrigerators into ovens.

[rabbitcreek]’s friend builds food caches with kids as part of a program to teach them traditional native activities. Food caches are usually inside buried boxes or small cabins raised on poles. Both are designed to keep hangry bears out. As you might expect, monitoring the temperature at these remote sites is crucial, so the food doesn’t spoil. His friend wanted a set-and-forget temperature monitoring system that could collect data for eight months over the winter.

The Alaska Datalogger carried a pretty serious list of requirements. It has to be waterproof, especially as ice and snow turn to water. Ideally, it should sip power and have a long battery life anyway. Most importantly, it has to be cheap and relatively easy for kids to build.

This awesome little data spaceship is designed around an O-ring used in domestic water purifiers. The greased up O-ring fits between two 3D printed enclosure halves that are shut tight with nylon bolts. Two waterproof temperature probes extend from the case—one inside the cache and the other outside in the elements. It’s built around an Adafruit Feather Adalogger and powered by an 18650 cell. The data is collected by visiting the site and pulling the SD card to extract the text file. There’s really no other way because the sites are far out of cell coverage. Or is there?

Though it probably wouldn’t survive the last frontier, this self-sufficient weather station is a simple solution for sunnier situations.

3D Printer Guardian Watches For Worst-case Failures

July 16, 2018 by Donald Papp 17 Comments

Some devices have one job to do, but that job can have many facets. To [jmcservv], an example of this is the job of protecting against worst-case failures in a 3D printer, and it led him to develop the 3D Printer Watchdog Guardian. When it comes to fire, secondary protection is the name of the game because it’s one thing to detect thermal runaway and turn off a heater, but what if that isn’t enough? The MOSFET controlling the heater could have failed closed and can no longer be turned off in a normal sense. In such cases, some kind of backup is needed. Of course, a protection system should also notify an operator of any serious problem, but what’s the best way to do that? These are the kinds of issues that [jmcservv] is working to address with his watchdog, which not only keeps a careful eye on any heating elements in the system, but can take a variety of actions as a result.

Some outcomes (like fire) are bad enough that it’s worth the extra work and cost of additional protection, and that’s the thinking that has led [jmcservv] to submit his watchdog system for The Hackaday Prize.

Arduino Watchdog Sniffs Out Hot 3D Printers

June 18, 2018 by Tom Nardi 23 Comments

We know we’ve told you this already, but you should really keep a close eye on your 3D printer. The cheaper import machines are starting to display a worrying tendency to go up in flames, either due to cheap components or design flaws. The fact that it happens is, sadly, no longer up for debate. The best thing we can do now is figure out ways to mitigate the risk for all the printers that are already deployed in the field.

At the risk of making a generalization, most 3D printer fires seem to be due to overheating components. Not a huge surprise, of course, as parts of a 3D printer heat up to hundreds of degrees and must remain there for hours and hours on end. Accordingly, [Bin Sun] has created a very slick device that keeps a close eye on the printer’s temperature at various locations, and cuts power if anything goes out of acceptable range.

The device is powered by an Arduino Nano and uses a 1602 serial LCD and KY040 rotary encoder to provide the user interface. The user can set the shutdown temperature with the encoder knob, and the 16×2 character LCD will give a real-time display of current temperature and power status.

Once the user-defined temperature is met or exceeded, the device cuts power to the printer with an optocoupler relay. It will also sound an alarm for one minute so anyone in the area will know the printer needs some immediate attention.

We’ve recently covered a similar device that minimizes the amount of time the printer is powered on, but checking temperature and acting on it in real-time seems a better bet. No matter what, we’d still suggest adding a smoke detector and fire extinguisher to your list of essential 3D printer accessories.

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Body Heat Sensing PC Security System

April 8, 2011 by Mike Nathan 25 Comments

lockifnothot

[Didier Stevens] wrote in to tell us about a little piece of PC security software he put together recently. His application, LockIfNotHot, works in conjunction with your PC as well as an IR temperature sensor in order to lock your computer the moment you step away.

The theory behind the system is pretty simple. Basically, the IR temp sensor monitors when you are at your desk, sensing your presence by the heat your body gives off. As soon as you step away however, it locks the computer since the temperature of the surrounding area immediately drops. It’s pretty simple, but as you can see in the video below, it works quite well.

The software has configurable set points and timeout values, which make it flexible enough to adapt to your specific situation. He happens to use an off-the-shelf IR sensor, but we assume any USB temperature module will do the trick. If you happen to work with sensitive information but often forget to lock your workstation, this is the program for you!

Continue reading to see a quick demonstration of his software in action.

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Growing Algae With An Arduino

October 2, 2009 by Matt Schulz 58 Comments

algae_grow

We’ve seen automated grow boxes of all shapes and sizes, but all were for growing plants. [Jared] over at Inventgeek wanted to do something similar for his algae. He started off with an Arduino-based solution that allows the controlled pulse of LEDs connected to his standard bioreactor as a prototype. Once he determined his proof of concept worked, he began work on a design based on the Arduino Pro Mini that has more advanced features such as temperature monitoring and algae culture density monitoring via some fancy IR voodoo. The code is open source and the hardware is easily obtainable, all that remains is the desire to grow algae.