[HN Gopher] DIY Raspberry Pi Spectrometer Guide
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DIY Raspberry Pi Spectrometer Guide
Author : robertelder
Score : 124 points
Date : 2022-01-21 18:26 UTC (4 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| anfractuosity wrote:
| Does anyone know what you call the mount with a screw that's
| holding the spectrometer for either the mini/larger version? I
| couldn't seem to see it mentioned in the readme.
|
| I tried something similar using just blu tack to hold the
| spectrometer to camera, from looking at the graph from it I think
| I possibly used the pi noir camera, as it can seem to see up to
| 900+nm or so.
| dljsjr wrote:
| I worked in a laser lab w/ an optical table in college and I
| believe it's called a beam probe mount. If you're referring to
| the black powder coated aluminum block w/ the through-hole and
| the tightening screw.
| KennyBlanken wrote:
| You can use a peeled-apart DVD and a USB web camera for a
| fraction of the cost. It's a design Public Labs came up with
| around 2012: https://hackaday.com/2012/08/27/turning-a-webcam-
| into-a-spec...
|
| Public Labs even developed a modified design that works with most
| smart phone cameras, among their follow-up work (such as testing
| high-end cameras:
| https://publiclab.org/notes/stoft/10-23-2016/high-rez-webcam... )
|
| The spectral response of the sensor is not linear, as it is
| designed to imitate human vision - and as anyone who read early
| 2000's digital camera reviews can tell you, even fancy cameras
| from well known manufacturers can have noticeably different color
| response.
|
| One benefit of Rasp Pi cameras is that genuine cameras could be
| evaluated and characterized, but counterfeits and such will be a
| problem. Same is true of USB web cams, I suppose.
| mncharity wrote:
| OT question: Is it possible to use a wedge-shaped slit (uneven
| width) to increase the dynamic range of a slit-grating-camera
| phone spectrograph?
|
| Backstory: I've repeatedly encountered deep confusion about
| color, even among first-tier physical-sciences graduate students.
| Yet color is widely taught K-2. Apparently without great success.
| So what might a rewrite, a modern learning progression for color,
| look like? Perhaps one based on spectra, a modern colorspace, and
| building on current understanding of color perception? Tablets
| are used in K - "find and take a picture of a circle". So how
| about using them for color? There's middle-school work with color
| "arithmetic" (an <R, G, B> binary triple with addition(light) and
| subtraction(filter)). And phone spectrographs are a thing.
| Thermal IR inspection cameras suggest having a context image aids
| understandability, and phones now have multiple cameras, so might
| one do a more accessible sample-with-context spectroscope app?
| With the light path folded flat, not sticking out? And a high
| dynamic range to permit sampling objects under ambient
| illumination? Might one craft a spectra-based introduction to
| color? For K?
| [deleted]
| showerst wrote:
| If you're into lasers, Les' YouTube channel is a goldmine.
| andai wrote:
| What would happen to the quality if the diffraction grating
| spectroscope were replaced with a prism?
| analog31 wrote:
| That can work too. You have to work out the range of angles
| that a given prism produces, not an unsolvable math problem.
| csdvrx wrote:
| Unfortunately, light spectrometer, not mass spectrometer.
|
| I'd love a DIY mass spectrometer or liquid chromatograph for
| biohacking!
| anfractuosity wrote:
| You might like - https://www.youtube.com/watch?v=nIKhUizkXxA (
| DIY mass spectrometer measures potassium in dietary salt
| substitute ) by Ben Krasnow
| nbernard wrote:
| As well as Chromatogiraffery's channel:
| https://www.youtube.com/channel/UCZ8l6SdZuRuoSdze1dIpzAQ
| shpongled wrote:
| I think you're going to have a very hard time doing any kind of
| actual (interesting) analysis on a DIY MS.
| cinntaile wrote:
| https://www.open-raman.org/
|
| You can try building that one. It's a DIY raman spectrometer.
| genericone wrote:
| Just in time to make a DIY plant-sap-analysis tool, perfect
| timing!
|
| Related: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4371691/
| forgotmyoldacc wrote:
| $70 seems expensive for a diffraction grating, what am I missing?
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