Re: [DIYbio] Re: Does Anyone Know Of A Submersible Arduino/RaspberryPI Compatible Spectrometer?

I didn't look closely into what you trying to do but if it is simple absorption (not polarized absorption) you don't need to have polarizer at all.

Regarding led coupling, it depends on your detector (what is on the exit of spectrometer). If that is sensitive and you don't need much light on it, just put the led close the fiber and enough light should go in. My hunch is that the detector sensitivity will be ok in VIS (UV is a problem, also your led emission in UV is questionable) and your problem would be ambient/stray light. I would pulse the diode and detect on that frequency if you can get spectrometer detector reading signal to work that way.

 

On Sunday, September 10, 2017 at 2:35:11 AM UTC-5, Cory Geesaman wrote:

I should add that the polarization on the images are indicated by a line crossing the fiber in the direction of the polarization allowed in the cross section (maybe I'll get lucky and they just etch them on to a normal polarization-maintaining fiber for their other polarized fibers so it will be nothing, keeping my fingers crossed.)

On Sunday, September 10, 2017 at 3:32:31 AM UTC-4, Cory Geesaman wrote:

I see you went with the Atlas sensors (I plan on using those too) - I'm not seeing ion detectors though - is that what you mean by being interested in it?  Thus far my best idea is the image below, I put an RFQ into Thor Labs for it which should allow for detection of just about anything in combination with the Atlas sensors, will see if they can do it.  Not so sure about the coupling on the LED cavity, but it should work reasonably well with the additional distribution of fibers dedicated to signal at various stages to account for losses.  The big questionmark in regard to whether or not Thor Labs will do it is the polarized fibers - those might be too much of a pain for them to align so many in a single cable, then pair them with an alignment in another cable (though it does kill off the need for collimators, polarizing beam splitters, prisms, and a bunch of other nonsense I was considering to couple the LEDs to the probe then get the signal back to a diffraction grating - everything else in the image seems to be stuff they already do.

On Saturday, September 9, 2017 at 8:59:05 AM UTC-4, Ravasz wrote:

Hi folks,

I thought I'll chip in as well as I am struggling with a similar project. I am building a closed bioreactor to grow algae with, and that can essentially do what you need it to: monitor nutrients/spectral characteristics of a body of water. I helped design a prototype a few years ago, there are instructables for that one here: http://www.instructables.com/id/Biomonstaaar/

At the moment I am trying to come up with a new design that allows for more automation but being a biologist my electronics knowledge is limited. At the moment I am hooking up demo sensors to an arduino board and using the instrumentino package (https://github.com/yoelk/instrumentino ) on a Pi to log and graph all the data but the system does not work too well.

So if you do come up with a design that work and could keep me posted I would be utterly grateful. Also, if you feel like looking into why I can't get my own system working that would be amazing.

Let me know if you find any of this useful.

Cheers,
Mate



On Thursday, 7 September 2017 01:58:33 UTC+1, Cory Geesaman wrote:

subjective*

On Wednesday, September 6, 2017 at 5:13:03 PM UTC-4, Cory Geesaman wrote:

I'm not sure which of the requirements you're considering objective.

Sent from my T-Mobile 4G LTE Device

-------- Original message --------

From: Jonathan Cline <jcl...@ieee.org>

Date: 9/6/17 5:03 PM (GMT-05:00)

To: Cory Geesaman <co...@geesaman.com>

Cc: DIYbio <diy...@googlegroups.com>, jcl...@ieee.org

Subject: Re: [DIYbio] Re: Does Anyone Know Of A Submersible   Arduino/RaspberryPI Compatible Spectrometer?

It's important to be as objective as possible when defining
requirements and when choosing appropriate tools to handle those
requirements (including the reasons behind those early requirements),
i.e. without bias.  It will make any project much more successful both
short and long term.   Most of the project failures I've seen could be
traced back to arbitrary decisions in the requirements or early design
process, not in the later implementation.


On 9/6/17, Cory Geesaman <co...@geesaman.com> wrote:
>I'm looking at sticking 20 of these things
> in different tanks in the same room not more than 50ft from a server room,
> and after that a bunch more of them outdoors not more than 5,000 ft away in
> the worst case scenario, I'd rather build some repeater shacks every 1,000
> ft



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