You mean hopocolor spectrometers are not viable or the tcd1304+transmission grating spectrometers are not viable?

Thanks for sharing these. I am quite aware of your work, following from your interactions with curious scientist on Pcbway project. So it’s glad to meet you here.

Simply beautiful

It makes me wonder what other scientific instruments are quietly undergoing similar transformations in unexpected places. Thanks to Leonhard for sharing the teardown images of hopocolor. and screenshots that sparked this observation.

These instruments are becoming viable tools for field measurements, where the cost-benefit equation of traditional spectrometers doesn't work. I think there is still room for improving these spectrometers in terms of cost & performance by using transmission grating with linear CCDs such as TCD1304.

These aren't just hardware upgrades. The manufacturers have developed desktop applications, mobile apps that run standalone or inside WeChat, and optional LCD displays. They're building complete measurement platforms, not just optical instruments.

Not only they use Czerny-Turner optical layouts - the same configuration found in laboratory spectrometers costing at least $2,000, they get you impressive specs: 350-800nm range, integration times from 50 microseconds to 10 seconds, and 2nm spectral resolution.

Compared to both Garden and Torch bearer spectrometers, what I'm seeing in hopocolor is entirely different: professional-grade spectrometers for just $250-$300, made by Hopocolor.

Then came torch bearer spectrometers, priced around $150-$200. Same general approach, but refined - better mechanics, improved optical alignment, more stable performance. Still using transmission gratings but executed with more care.

Previously, I covered garden spectrometers - the only spectrometers you could buy for under $100. These are simple enough: transmission gratings paired with camera sensors with Bayer filters removed. They worked but were basic. bsky.app/profile/chin...

3/3 The complete design files, firmware, and mobile application are available as open source under GPL 3.0 license at lnkd.in/eSq-asPH
Here is the ink to the ODX paper: doi.org/10.1021/acs....
The corresponding tweet that went viral is here:
x.com/VarunKothama...

2/3 ColorX extends this concept by repurposing fitness trackers as portable instruments capable of detecting five critical water quality parameters: nitrite, sulfate, chromium, free chlorine, and turbidity, with detection limits meeting EPA/CDC guidelines.

youtube.com/shorts/27e49...

Of course the #pocketspectrometer can be used without the web interafce with its own UI enabled by its own screen and two buttons on the #M5stickC. Here is the link to the github repo github.com/devpnryn/Poc...

Here is the video tutorial on how to use the #pocketspectrometer’s web interface. We had a french intern student (Gabriel Kirady) who kindly recorded this video while using the spectrometer. #OpenSource #Spectrometer #STEM #DIY #CitizenScience #Instrumentation #OpenHardware