Lego Spectrometer
question:lego-spectrometer

This is the latest version of Public Lab's DIY Desktop Spectrometry Kit -- the Lego Spectrometer. It addresses issues of rigidity, sourcing, modularity, and image quality over previous versions. We've been making and distributing [Do-It-Yourself spectrometers](/w//spectrometry) since 2011, and have been through [4 major kit versions](http://store.publiclab.org/collections/spectrometry) and hundreds of different community contributed modifications, new versions, changes, and more. ## Get a kit This is an open source kit, so you can just build your own -- but to **order parts for a kit**, visit the Public Lab Store: ## Design goals Over the years, we've identified a few really critical improvements that have been tough to solve: * rigidity * easy to source parts * modularity - working together * image quality Our mission is to make it **easier, cheaper, and more accessible to do environmental monitoring**, and to do that as an open source, collaborative community. And of course part of that is cost -- while people build upon our kits with more expensive options and upgrades, we want the basic kit to be extremely affordable. ## Quick start [notes:grid:lego-quickstart] ## Questions [questions:lego-spectrometer] ## Building your Lego Spectrometer [activities:lego-spectrometer] ## Spectrometry activities [activities:spectrometry-sampling] **** ## Spectrometer calibration [activities:spectrometry-calibration] **** [![tinkercad.png](https://publiclab.org/system/images/photos/000/022/935/large/tinkercad.png)](https://publiclab.org/system/images/photos/000/022/935/original/tinkercad.png) _Tinkercad model, below_ ## Parts ### 3D models * Tinkercad: https://tinkercad.com/things/43IqCTHE7Iz * Thingiverse: https://www.thingiverse.com/thing:2711528 ### 3D brick models Lots of great brick models are available here: https://printabrick.org/ and on http://thingiverse.com * assorted standard bricks: https://www.thingiverse.com/thing:2626413 * holey bricks: https://www.thingiverse.com/thing:1095326 * sloped brick: https://www.thingiverse.com/thing:527185 * corner L brick: https://printabrick.org/bricks/2357 * brick w/ peg: https://printabrick.org/bricks/2458 (I used this instead of a 1x2 hole brick + a friction peg, because I couldn't find a model for the brick) Brick dimensions are nicely described in this diagram from Wikipedia: https://commons.wikimedia.org/wiki/File:Lego_dimensions.svg Print files for the black cardstock insert can be [found here](https://publiclab.org/notes/abdul/10-19-2016/foldable-paper-spectrometer-instructions). ...


Author Comment Last activity Moderation
warren "Oh, interesting! Maybe @programmer1200 would be interested in this, re: related work on a turbidity sensor... " | Read more » about 6 years ago
Ag8n "The current epa method for turbidity, with standard prep, is at: Https://epa.gov/sites/production/files//2015-08/documents/method_180-1_1993.pdf ..." | Read more » about 6 years ago
UHF "DVDs work better with smaller track separation and therefore greater diffraction. " | Read more » over 6 years ago
warren "Hi! There are a few posts exploring this question here: https://publiclab.org/questions/dsvilko/06-13-2017/any-way-to-improve-on-the-dvd-grating ..." | Read more » over 6 years ago
Ag8n "It sounds like Warren answered the question. I can give some more background. Proteins contain nitrogen, which isn't present in many other milk c..." | Read more » over 6 years ago
stef "What I was alluding to is that with all of the filter attenuation, the cmos sensor was still overloaded. This can be seen in the spectra submitted..." | Read more » over 6 years ago
Ag8n "There are two approaches to this, the hardware and software. Sounds like you took care of the hardware end very well. Can you think of any softwa..." | Read more » over 6 years ago
warren "Hi, would this help? https://publiclab.org/notes/wagnerc4/02-05-2014/fat-percent-in-milk I think it's fat percent, not proteins, but it could be s..." | Read more » over 6 years ago
stef "I have used photographic neutral density filters and have not been able to view the sun directly using the spec3 highly modified device. The attenu..." | Read more » over 6 years ago
Ag8n "Only one suggestion then. Sunlight can be strong. As a safety measure, partially block the sun and work your way up to full exposure. Might not ..." | Read more » over 6 years ago
jsbonillam "I am going to make and analyse the graphs with the wavelength and absorption. " | Read more » over 6 years ago
Ag8n "Please forgive the question, but what lines are you using and what method of analysis? Thank you for the information. " | Read more » over 6 years ago
warren "Oh, i don't know, but it looks very cool! " | Read more » over 6 years ago
jsbonillam "@warren The camera will be just part of the spectrometer. I am still considering whether to use LDRs (light depending resistors), as here http://ww..." | Read more » over 6 years ago
warren "How would you set up the spectrometer next to the other equipment, or the tracker? Are you using a raspberry pi camera as-is, as well, or just as p..." | Read more » over 6 years ago
warren "I think the Lego spectrometer's suitability for this is an open question, but the Raspberry Pi Camera v2 is very low noise and could be worth testi..." | Read more » over 6 years ago
warren "I think either would work, but haven't tried it myself. Once you get this assembled, please do and share your results! " | Read more » over 6 years ago
Ag8n "The device referenced has very mixed reviews on the internet. And it does seem pricey. As a suggestion, borrow or rent one first. Try it and see..." | Read more » over 6 years ago
zayas "Here is a device ( https://www.consumerphysics.com/business/ )we have considered using as it offers a self contained hand held unit suitable for co..." | Read more » over 6 years ago
zayas "Thank you for the article! As mentioned in my posting, BRIX has been a standard tool used in the field ( current Consumer/Business product in the ..." | Read more » over 6 years ago
jht001 "Here is an article from Ohio State University Extension on using Brix to measure vegetable quality Artice link " | Read more » over 6 years ago
Ag8n "Absolutely correct. The fluorescence spectrometer is the same layout as for the basic turbidimeter. The standards are a bit of a pain, but quite ..." | Read more » over 6 years ago
warren "So a design using the Lego Spectrometer, for example, might need a right-angle light source -- but that's not so bad, since already with fluorescen..." | Read more » over 6 years ago
warren "Hm, good point -- actually going back to an old post there's some great stuff here: https://publiclab.org/notes/donblair/08-25-2015/turbidity-001 ..." | Read more » over 6 years ago