[DIYbio] Re: 4-tube incubator and optical density meter arduino shield

On Oct 7, 5:46 pm, Mackenzie Cowell <m...@diybio.org> wrote:
> I'd like to build a simple incubator+OD meter for up to 4 microcentrifuge
> tubes....

My first quick comment is that you might have a look at the following:

http://soslab.ee.washington.edu/mw/images/e/ef/EE449_SP10_Group6_MS5_Report.pdf

In that, they used LEDs and a Light-to-Frequency Converter called a
TSL230 which I think they interfaced with the Arduino.  They seem
confident in their results.
I'm in the process now of testing an OD system using a similar set-up,
but it's taking OD readings and some other optical properties through
a syringe, not microcentrifuge tubes.  Also, I'm not familiar with the
Arduino and have built my system around the Propeller microcontroller
- sorry.  I have an incubator built around the syringes using non-
inductive resistors, but I haven't yet tested the incubator portion
yet.  I have digital thermometers using DS18B20's.  Although I've
heard of people using PCB traces for heating, it seems to me it might
be easier to use resistors because they can be positioned around the
microtubes without dramas.

Anyway that's it for now.
hope that helps get you started,
Mark