I have been working on the following during the last week:

• Actinic light pulse control with the Arduino. The Arduino controls the LED driver via a PWM pin and it uses a optocoupler and a resistor to solve the voltage variation between the driver and the Arduino (10v vs 5v).

• Light intensity control with some microcontrollers (manual stage, but will be coded all together within one Arduino code later on)

• Light Intensity calibration using the PAR sensor and the Spectrometer

I wanted to have 500 umoles of light under the chamber, and I also wanted to make sure that it's got the shape (or wavelengths) I want, which I use the spectrometer for. The spectrum is more or less 60% Red, 25% Blue and 15% White. That should please the most demanding plants :) 

You can see that I have bundled up together the PAR and the fibre with the cosine corrector using a lab stand with a clamp.

I use the spectrometer to adjust the spectra to the ratios I want.

You can see that I had to migrate from my garage to my home office due to weather conditions (is fall in Europe).

It has taken quite a bit of space though!

Want to see some results?

Above, a nice fluorescence sequence with an initial pulse, followed by 500 umoles and 2-minutes interval pulses.

Finally, a nice picture of cactus sunbathing within the chamber!

Back to work fellas...