Thermal Flashlight
thermal-flashlight

A "Thermal Flashlight" is a DIY device which lets you do a kind of "light painting" -- [thermal photography](/wiki/thermal-photography). It produces a colored "heat map" overlaid directly onto a photo of a room. This is the simplest, cheapest, and to date, most effective way we have developed of measuring heat leaks or cool leaks indoors and outdoors. Simply put, the "flashlight" puts out redder light if it's pointed at something hot (default 75 deg F or more) and bluer light if it's pointed at something cold *(default 60 deg F or less). ### Parts The Melexis MLX90614 digital thermometer used in this kit can be found in a few places, at different price points: * [Adafruit.com](https://www.adafruit.com/product/1747) * [AliBaba.com](https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&CatId=&SearchText=Melexis+MLX90614+3V&viewtype=) ### Assembly There are a few versions of the thermal flashlight: [notes:grid:activity:thermal-flashlight-assembly] ### Questions [questions:thermal-flashlight] **** ### Activities [activities:thermal-flashlight] **** ### Using a Thermal Flashlight To capture the light painting over time, we have been using timelapse photography or this [p5js.org sketch](https://editor.p5js.org/jywarren/present/dl7B2Upp-) ([source](https://editor.p5js.org/jywarren/sketches/dl7B2Upp-)) (or its inspiration, GlowDoodle), as seen in the top image on this page. * Within view of the camera or laptop, sweep the flashlight beam over the scene at a distance of about 12 inches. * Try to stay out of the way of the beam, and don't point it directly at the camera or it will create a "starburst" and may mess up your image. * It's helpful to wear dark clothing so you don't show up in the image as you're moving around. ### Building your own **Parts list** For a Thermal Flashlight with 3.6 V Melexis Sensor and Common Anode LED. * 1 [Melexis MLX90614](http://www.futureelectronics.com/en/technologies/semiconductors/analog/sensors/temperature/Pages/6314181-MLX90614ESF-DAA.aspx) non-contact IR thermometer (3v). Data sheet: http://www1.futureelectronics.com/doc/MELEXIS/MLX90614ESF-DAA.pdf * 1 [common-anode RGB LED](http://www.sparkfun.com/products/10820) * 2 4.7k Ohm resistors * 2 100 Ohm resistors * 1 180 Ohm resistor * 1 0.1 μF capacitor * wire * [a breadboard](http://www.sparkfun.com/products/7916) or circuit board & soldering eqmt. * [Arduino](http://arduino.cc) * 9v battery and holder **Software** thermal-flashlight.zip Gist: https://gist.github.com/sdosemagen/1739961/ _Note: The goal of this file is to be a place to download everything without pursuing other links. If there are changes or updates please feel free to add and re-upload. If the file is missing anything, please comment below. You might notice that this is for the 5v Melexis, but it will work for either without issues. Alternative variations of the Flashlight can be made with a 5.5V Melexis Sensor and Common Cathode LED. For the 5.5 V sensor follow this diagram: http://publiclaboratory.org/notes/sara/2-7-2012/circuit-diagram-5v-melexis-sensor For the common cathode circuit board follow this diagram: http://publiclaboratory.org/notes/warren/2-11-2012/common-cathode-variant-thermal-flashlight-code Links to purchasing equipment: ### Consumable Parts * LEDs (1 per flashlight, but they sell as a pack of 25): http://www.sparkfun.com/products/10818 * Arduino Uno (1 per flashlight): http://www.sparkfun.com/products/11021 * Capicator (1 per flashlight): http://www.sparkfun.com/products/8375 * Resistor pack (this pack has a 180 ohm resistor which we found other packs not to have): http://www.eio.com/p-19326-velleman-kres-e12-pack-of-610-e12-series-resistors.aspx * 3.6 V infra red thermometer (1 per flashlight): http://www.futureelectronics.com/en/technologies/semiconductors/analog/sensors/temperature/Pages/6314181-MLX90614ESF-DAA.aspx. Data sheet: http://www1.futureelectronics.com/doc/MELEXIS/MLX90614ESF-DAA.pdf If you are starting an electronics kit from scratch: * a 40Watt soldering Iron (if you want it to be permanent otherwise duct tape or Velcro works temporarily) * hookup wire (solid not stranded- 22 or 24 gauge, you can get this at Radio Shack) * pliers called "wire strippers" to get the plastic wrap off the hookup wire (can get at Radio Shack) * solder for 40Watt iron, lead-free. * a breadboard (1 per flashlight). If you aren't soldering: http://www.adafruit.com/products/64. If you are soldering: https://www.adafruit.com/products/571. * a USB cable to connect the arduino to the computer via USB for power 5Volts (can get at Radio Shack) * household sponge for cleaning solder off tip * 9 volt battery with connector wires (can get at Radio Shack- 1 per flashlight) ***Cost: ~$40-$60*** **** ### Updates All research on PublicLab.org about the thermal flashlight project: [notes:thermal-flashlight] **** Several meetups have been organized to build and test thermal flashlights, at RISD (Providence, RI) and in Brooklyn, NY. We are organizing one now in Somerville, MA: * [Thermal Flashlight workshop](/wiki/thermal-flashlight-workshop) * [May 26 AS220 workshop](http://publiclab.org/wiki/may-26th-as220-thermal-flashlight-workshop) * [Thermal Fishing Bob presentation from NE barnraising](http://publiclab.org/notes/Kaya9804/06-09-2014/thermal-fishing-bob-presentation-from-the-ne-barnraising) ## Thermal flashlight heatmaps **** ## Custom thermal flashlight circuit boards Instead of building off of an #Arduino, it's possible to make a Thermal Flashlight using a custom circuit board. The circuit board files can be found here: https://github.com/Pioneer-Valley-Open-Science/thermal-flashlight ##Photos [![IMG_0779.JPG](https://i.publiclab.org/system/images/photos/000/003/132/medium/IMG_0779.JPG)](https://i.publiclab.org/system/images/photos/000/003/132/original/IMG_0779.JPG) [![IMG_0781.JPG](https://i.publiclab.org/system/images/photos/000/003/133/medium/IMG_0781.JPG)](https://i.publiclab.org/system/images/photos/000/003/133/original/IMG_0781.JPG) ...


Author Comment Last activity Moderation
mathew "Well, I saw the device and did a patent search for Black & Decker-assigned patents and thermal sensing-- it didn't take too long. does their c..." | Read more » over 9 years ago
sara "Interesting Matt, how did you find out about their patent? I wonder if the Berkman Center for Internet and Society would be interested in discussin..." | Read more » over 9 years ago
mathew "great route plans! really good pre-trip planning. awesome! " | Read more » over 9 years ago
acnud "Our "tech failure" was that the temp sensor stopped working - was not picking up any reading at all. The light was just "on". The flashlight was ca..." | Read more » over 9 years ago
warren "I guess possibly not, from the video. You should embed it in this research note! Loved the music. " | Read more » over 9 years ago
warren "Is it possible that the environment was cold enough that you were well below the range that would appear to be anything but blue? What was the rang..." | Read more » over 9 years ago
ckenny "Please excuse my inability to take video horizontally! " | Read more » over 9 years ago
KKMS "Looks great you all! :D " | Read more » over 9 years ago
btbonval "As an example of something with low specific heat capacity, you could fill your fridge with metal pots. Although the pots won't fall out of the fri..." | Read more » over 9 years ago
btbonval "As a heads up, the contents of the refridgerator can make a huge difference. If you have a fridge with nothing in it at all, the fridge is only co..." | Read more » over 9 years ago
sara "Thanks for sharing your project! Particularly the easily made error of covering up sensor. It's a great reminder to the rest of us! " | Read more » over 9 years ago
sara "Hi Julia, awesome work! Could you give a little more detail on what's in each picture? " | Read more » over 9 years ago
bsugar "Greetings from Barn Raising 2014. Live from Lumcon! We just finished a wonderful workshop on this tool, and there was a bit of a kerfuffle (sligh..." | Read more » over 9 years ago
donblair "Follow-up -- there's some nice info on IR photodiodes (at least the sort that are in a typical IR remote), here -- including a link to a datasheet...." | Read more » over 10 years ago
donblair "Yay! Yeah, I puzzled a bit over the best geometry of 'emitters and receivers' to use on the device. I have two photodiodes on the board, one of w..." | Read more » over 10 years ago
mathew "The circular layout will make concentrating the different LEDs towards a common point easier. good thinking. " | Read more » over 10 years ago
warren "Exciting! " | Read more » over 10 years ago
sekjal "Can't wait to get my hands on the updated version and build some sweet Lego cases/containers/contraptions! " | Read more » over 10 years ago
donblair "And here's a nice way of doing color mixing using a ping pong ball as a diffuser: https://teachers.web.cern.ch/teachers/archiv/hst2005/part_sessio..." | Read more » over 10 years ago
donblair "Mathew -- AIR HOGS! Just watched the video -- WHUUUT!! We've got to do this! That's so much fun! We could be sampling the entire room remotely!..." | Read more » over 10 years ago
mathew "Sekjal, It would be really cool to have a rangefinder, but they're pricey sensors, and might significantly up the cost of the board. Don- I fixed ..." | Read more » over 10 years ago
sekjal "If we can determine the change in reading to be purely a function of distance alone, perhaps adding an ultrasonic rangefinder to the IR sensor/serv..." | Read more » over 10 years ago
donblair "Mathew -- I have never been so eager to follow a missing link -- where's the wall-climbing remote control toy car?! :) Wait a minute -- are you su..." | Read more » over 10 years ago
mathew "This is a really neat idea. thanks for working on this distance calibration. I have a stud finder that has felt on the bottom, and sounds similar..." | Read more » over 10 years ago