The greenhouse project
What's measured
Links
Temperature
 Green house with one vent door open |
The temperature is simple to measure as the sensor is on the logger itself. It's ranging from -50 to +125 degrees C (but I don't think the logger would stand for that) with ½ degree resolution. I can programmatically change the resolution or the range to use one byte of data instead of two.
Vent doors
Four of the six vent doors in the roof are automatically opened by the sun (uses no power). I monitor to what extent they (at least two of them) are open. I have built two small open aluminum cases which holds a standard potentiometer. The potentiometer is connected to the door. In the picture you may think that the arm is not parallel with the door. But it is parallel to the imaginary line from the turn point of the door.
 Door sensor |
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Water level
Beside the greenhouse is a small house for tools etc. located slightly above the greenhouse. Rain water from the house is collected into a 200 liter barrel. It's capable of feeding the automatic irrigation system for the greenhouse. In the future I will measure the water level in the barrel, so I know when to fill it during the dry periods.
Humidity
I will also measure the humidity in the soil in the greenhouse, to see it gets the right amount of water.
The water level and humidity sensors are described at the Parallax site. Look for earth measurements.