[Bio] Post-meeting thoughts and NIR probe

Rolf rolfvw at gmail.com
Wed Apr 6 22:28:01 PDT 2011


Hey Sean,
I just took a quick look at these.
Such devices are mostly meant for an "on or off" kind of detection,
you know, like, is the metal tab in the slot or not.

It's possible it could be adapted, who knows?
And it is cool that it already sets up a fixed gap.
But, I think for the NIR probe, it is better to pick an
emitter and detector that is matched for the IR frequencies we want.
We get more specs in those datasheets too :-)
Cheers,
-rolf

On Wed, Apr 6, 2011 at 10:35 AM, Sean Cusack <sean.p.cusack at gmail.com> wrote:
> Hey kids!
>
> So, I was taking a peek through Jameco today to see what kinds of
> phototransistors could be used for the DO sensor, and came across these cool
> dillios:
>
> https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1872986_-1
>
> Essentially, we've got an IR LED with a phototransistor all in one package.
> Its designed to do solid object sensing, but wouldn't it be possible to use
> this as our spectrophotometer? I think using this guy could solve a lot of
> problems - the mount is already designed, the gap spacing is well
> characterized, and everything already lines up.
>
> Do people have experience using these kinds of things, or should I go ahead
> and order a couple?
>
> Sean
>
> On Tue, Apr 5, 2011 at 11:56 PM, Rikke Rasmussen
> <rikke.c.rasmussen at gmail.com> wrote:
>>
>> Hey all,
>>
>> Thanks for a great meeting yesterday, pleasant and very informative in
>> spite of weekend-wear and happy KDE people at Noiseybridge!
>>
>> Rolf, the OP506B looks just perfect - 100% relative response at 850nm, and
>> schematics so simple even I can follow them - brilliant! Ihave just been
>> reading through the attached .pdf on the wonders of single-colour NIR for
>> biomass measurements, published by one of Optek's competitors, mainly for
>> calibration equations + curves. Also a nice basic intro to
>> spectrometry, should anyone else be curious.
>>
>> Charlie, thanks so much for the blog post - was on my way to give a
>> somewhat wishy-washy update, and there was this brilliant, high-level
>> discussion of thermocouples and thermistors with pics and all! Check it out,
>> everyone!
>> In other news, there will be both destillation and kombucha brewing and
>> bottling to have fun with tomorrow night at Noisebridge, approx. 7pm - come
>> hang out, help out...or both!
>> /Rikke
>>
>> On Wed, Apr 6, 2011 at 12:18 AM, Rolf <rolfvw at gmail.com> wrote:
>>>
>>> Hi Folks!
>>> It was good to see everyone yesterday, and get updated on what people
>>> are working on.
>>> Too bad it got so noisy at Noiseybridge!
>>>
>>> I went ahead and ordered some parts today (will expense with Rikke
>>> soon) for the
>>> pH amplifier.  It's going to be quite an effort.
>>> I also will get some phototransistors for the NIR probe.
>>>
>>> I found some parts that are well matched for the 850nm IR LEDs that I
>>> brought in
>>> yesterday.  It's the Optek OP506B.  They cost 80 cents each.
>>> A very simple circuit is required around it, and it might even work
>>> with a couple
>>> resistors.
>>> I think the probe will require 3 wires:  +5v power, signal output, and
>>> GND (hopefully shielded).
>>>
>>> If these parts work, then the mechanicals should be straightforward.
>>> The LED and the detector are both 3mm LED-like packages.
>>> This should make it easier to design a probe around it.
>>>
>>> Cheers,
>>> -rolf
>>>
>>>
>>> On Sun, Apr 3, 2011 at 1:37 AM, Rikke Rasmussen
>>> <rikke.c.rasmussen at gmail.com> wrote:
>>> > Hey all,
>>> > Welcome to the Biobridge mailing list! By way of introduction, here's a
>>> > quick update on present status and future plans for the BioBridge
>>> > group.
>>> > Our current project, the BioBoard, one of the entries in the Great
>>> > Global
>>> > Hackerspace Challenge, is coming along really nicely. For any
>>> > subscribers
>>> > unfamiliar with the project, we're basically building a bunch of
>>> > different
>>> > sensors (temp., pH, dissolved oxygen, NIR spectrometer), hooking them
>>> > up to
>>> > a microcontroller and transmitting the sensor data to a server
>>> > somewhere
>>> > with a web app that plots a nice graph for you so you can monitor your
>>> > microbial culture in real time from the comfort of your couch.
>>> > What we've got so far:
>>> > Sensors
>>> > - thermometer: 2 different set-ups (one-wire digital thermometer,
>>> > thermistor), both functional (yay!) - Charlie's the man here
>>> > - pH: several leads, and at least two good brains chippin' away at the
>>> > problem  - Rolf and Otute are the dudes on the job
>>> > - dO: solvent sandwiched in a cheap and beautiful mylar/vinyl bilayer,
>>> > catalyst to arrive on Thursday - Sean's got it down
>>> > - NIR: have a fairly decent plan for the LED/photosensor part, but need
>>> > help
>>> > regarding circuitry and wiring - Rikke's fumbling with this one
>>> > Microcontroller
>>> > - Arduino board + ethernet shield have been successfully delivered to
>>> > Marc
>>> > (I hope?)
>>> > - alternative suggestions have come up, we'll go through the pros and
>>> > cons
>>> > of each on Monday
>>> > Software
>>> > - we've been given an Arduino sketch for above assembly
>>> > Project group meetings are on Mondays at 7:30pm at Noisebridge, (new)
>>> > deadline is March 3rd. Current plan is another 2 weeks of sensor
>>> > building,
>>> > then a week of assembling and testing and a final week of fine tuning
>>> > the
>>> > final product. All of this ends in a big finale at Maker Faire (where
>>> > Biobridge will hopefully also be represented at the Noisebridge table
>>> > at
>>> > least some of the time), May 21st-22nd.
>>> > Once Maker Faire is over, it is my hope that we can start hosting
>>> > regular
>>> > classes at Noisebridge - both theoretical (intro to general
>>> > microbiology,
>>> > specific aspects of bacteriology/mycology/phycology as relevant,
>>> > biochemistry/molecular biology/genetics, ecology & evolution) and
>>> > practical
>>> > (aerobic/anaerobic fermentation, bacterial/algal cultivation, mushroom
>>> > growing, selection/mutagenesis/mating group experiments, basic
>>> > transformation, whatever else we think of or find someone to teach)
>>> > ...in
>>> > short, all the fun we can have with microbes. We might well use the
>>> > wiki to
>>> > plan this - all input is valued!
>>> >  Thoughts, ideas, comments?
>>> > /Rikke
>>> > _______________________________________________
>>> > Bio mailing list
>>> > Bio at lists.noisebridge.net
>>> > https://www.noisebridge.net/mailman/listinfo/bio
>>> >
>>> >
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