Having
added a realtime clock to my Boarduino, I'm now on to measuring the humidity and temperature inside the vivarium. This iteration displays the current reading along with the time on the LCD. Eventually, I plan to capture the data so I can graph how these are changing over the course of the day.
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Masdevallia with AM2302 Temperature / Humidity Sensor |
Incremental Bill of Materials
New to this step is a temperature / humidity sensor from
Adafruit Industries. I went with the AM2302 since I think the DHT22 will give a reasonable amount of accuracy and I liked the larger plastic housing. I did end up soldering a scrap length of CAT5 cable to the sensor's wires to make the wires long enough to get out of the vivarium to the board.
(The full bill of materials is provided at the end of this post)
Wiring
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Components with Logical Connections |
- The AM2302 runs on 5V along with the LCD and RTC.
- The ground line is connected to common ground.
- The data line is connected to digital pin 2 on the Boarduino.
Code
Initial setup of the sensor involves creating a new DHT object and passing in the data pin and sensor type as parameters.
Each pass through the loop, read the values from the sensor. The sensor only produces readings every two seconds, so this might be better reduced to only reading every 5 seconds or some other arbitrary interval.
Full source code is available on github:
https://github.com/dmalec/Project-Masdev/tree/master/masdev_temp_humid
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LCD Showing Time, Humidity, & Temperature |
Full Bill of Materials
The next step is
recording the temperature and humidity readings to an SD card and graphing the data using RRDTool.