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: * []( * []( ### 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 [ sketch]( ([source]( (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]( non-contact IR thermometer (3v). Data sheet: * 1 [common-anode RGB LED]( * 2 4.7k Ohm resistors * 2 100 Ohm resistors * 1 180 Ohm resistor * 1 0.1 μF capacitor * wire * [a breadboard]( or circuit board & soldering eqmt. * [Arduino]( * 9v battery and holder **Software** Gist: _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: For the common cathode circuit board follow this diagram: Links to purchasing equipment: ### Consumable Parts * LEDs (1 per flashlight, but they sell as a pack of 25): * Arduino Uno (1 per flashlight): * Capicator (1 per flashlight): * Resistor pack (this pack has a 180 ohm resistor which we found other packs not to have): * 3.6 V infra red thermometer (1 per flashlight): Data sheet: 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: If you are soldering: * 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 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]( * [Thermal Fishing Bob presentation from 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: ##Photos [![IMG_0779.JPG](]( [![IMG_0781.JPG](]( ...

Author Comment Last activity Moderation
sekjal "There are Lego bricks for just about anything :) I was thinking that, since there are screw holes in the corners of the board already, flat topped..." | Read more » over 10 years ago
donblair "This is fantastic! I didn't know there were Lego parts that did that sort of height adjustment thing :) Your results are really important -- so n..." | Read more » over 10 years ago
ajawitz "The "REVA" board looks awesome! It looks like you can get a lot of the components you use at Adafruit now for a good price too, so that might help..." | Read more » over 10 years ago
donblair "Yeah! It's fun to picture this device being used in the mode of an old-fashioned 'light meter' held next to an infragram camera and which accounts..." | Read more » over 10 years ago
warren "wow, sweet -- i wonder if this could also be used to calibrate NDVI with a more absolute brightness measure. Ned would know more about this... " | Read more » over 10 years ago
warren "woohoo! " | Read more » over 10 years ago
donblair "Here she is! IR sensor hasn't yet been placed, but here's the basic idea: " | Read more » over 10 years ago
donblair "Hi Jeff -- great idea! That's how they currently do it on the design, too. For reference, students could use the LeoStick Eagle design f..." | Read more » over 10 years ago
warren "I wonder if we could do both USB types, at least on the board? Jack, do you think adding a USB stick thing would be an interesting thing for your ..." | Read more » over 10 years ago
donblair "Thanks Jack! Great to hear re: your surface mount experience. I'm looking forward to trying it out myself. I haven't ordered a stencil -- but tha..." | Read more » over 10 years ago
warren "wow don!!! is that avr a version with built in USB? could we add a USB dongly thing like the visualight board has? " | Read more » over 10 years ago
JSummers "Hi Don, That looks really good! Did you order a stencil too? I just had my first experience soldering with paste solder and a stencil, and I was..." | Read more » over 10 years ago
warren "image broken? jack - the "diy" version is the one I have, but I dunno if that's the one theyre currently selling. but are the 4 holes we want on t..." | Read more » over 10 years ago
donblair "Hi All, Great discussion here. It sounds to me like designing the breakout board for the Visualight would be an excellent student project, and co..." | Read more » over 10 years ago
JSummers "That last comment surprised me. Turns out there are three versions of the board at the github site; The one I was looking at has four holes on 0.2"..." | Read more » over 10 years ago
warren "And indeed the eagle files also show 5 holes. The Fritzing diagram was actually just a screenshot of the Eagle board file, Photoshopped over a Frit..." | Read more » over 10 years ago
warren "It has five holes. The Fritzing diagram was a crude reproduction by me, so it's not likely to be accurate. The Eagle files are from Visualight; the..." | Read more » over 10 years ago
JSummers "Hi Jeff, I downloaded the eagle files that you can get to from the link that you reference and used the measurement tool in eagle to get the heade..." | Read more » over 10 years ago
warren "Sure, that'd be interesting. Do you think Don's are too complex? You know, I'm not sure what the spacing is on the Visualight. Do you think you co..." | Read more » over 10 years ago
JSummers "Hi Jeff, I plan to have some of my students make a few simple pcbs to introduce the eagle software and teach some quick and dirty fab methods. I ..." | Read more » over 10 years ago
cfastie "It's going to be 40° F on Thursday, Friday, and Saturday, so if you want to collect environmental data inside the SNOWFEST igloo, the RIFFLE might ..." | Read more » over 10 years ago
ajawitz "RE- Through hole kits- Interestingly enough... It appears we're not the only one's talking about an ATmega32u4-based breakout as this Kickstarter ..." | Read more » over 10 years ago
donblair "Hi! Sorry for the delayed reply -- been a bit crazy with other projects, but still excited about this! On reflection, rather than add extra power..." | Read more » over 10 years ago
ajawitz " Do you have a link to the Visualight schematics? I should check them out, as Jeff was hoping to use their more powerful LED, and we might be abl..." | Read more » over 10 years ago