We’re always a little surprised by how well a vacuum thermos works, but eventually the contents will cool down (or warm up depending on what’s in there). [Gamesh_] added a temperature meter to his thermos using an Arduino and a temperature sensor. The original post is in Portuguese but [Bruno] republished it in English.
The temperature sensor has been repurposed from a digital thermometer meant for taking your temperature. Holes for the LEDs making up the indicator bar were melted in the side of the plastic housing. When the hot liquid is poured out at about 0:45 into the video you can glimpse the Arduino hanging our on the other side of the pot and a power cord running off behind the laptop. It would be nice to see this migrated over to a less powerful chip and run from a small coin cell, but we like the concept.
Unlike regular thermometers that can get incorrect readings because of the sun’s heat, shading, and airflow, aspirated thermometers isolate the temperature sensor from precipitation and the sun, while providing constant air circulation. Take ten 1-wire T2SS boards and combine them with DS18B20s and you’ve got yourself the start of an aspirated thermometer. A foot of PVC pipe, fans, and the above mentioned parts and you’ll have accurate temperature readings in no time.
[Dave] made his to control a natural gas boiler, pumps, and 11 gas-fired unit heaters for a combined output of 5.3 million BTUs per hour – keeping his greenhouse nice and toasty.
Update: Thanks Firetech for pointing out our silly typo.
The guys over at NerdKits put together a really informative video on a meat thermometer using predictive filtering which is viewable below. The video, supplemental text, and code is available on their website. The thermometer is constructed of a LM34 temperature sensor attached to a piece of 12 gauge solid copper wire. The thermometer signal is processed on an ATmega168 microcontroller and visualized using the pygame library for python. The real gem in this project is their excellent explanation of predictive filtering, which could easily be utilized for a large number of projects.
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This digital thermometer won’t win any awards for being something innovative and new, but we really like how it looks. The bar graph style display adds something to the project that a normal character display just wouldn’t. You can download source code and schematics on the site.
[Chris] sent in the Thermosmart. It is an Arduino controlled thermostat. It has a web interface which allows him to see the current temperature and make adjustments from remote locations. He can set heating or cooling to on, off, or auto and adjust the ranges as well. We’ve seen similar done with an Arduino before, even one with a nice LCD interface. This could possibly be useful for remote plant monitoring as well.
[Peter] sent in this writeup on how to build a remotely accessible thermometer. The hardware side is pretty easy on this one, all you need is an Arduino, a resistor and an thermistor. The software is where the main focus is. You can check the temperature via command line, but also via email. It can also tell you the temperature using the host computers sound hardware. You can see a video of it in action after the break. We have to wonder why he didn’t make it twitter.
Continue reading “Remote thermometer using Arduino”
Here’s another nerdy present that was built for Valentine’s Day. [João Silva] created a temperature sensing Munny. A Munny is a vinyl toy made to be customized. Other than these Munny speakers, we haven’t seen them in many electronics projects. The LM35CZ temperature sensor has an analog output that connects to the ADC on the ATtiny15L. The microcontroller changes the RGB LED’s color based on the temperature: blue for cold, green for comfortable, and red for hot. It only flashes every three minutes to conserve the power in the coin cells. His one-off circuit board also includes an ISP header for programming. The Munny’s head looks like it does a great job diffusing the light.