https://github.com/jervine/rpi-temp-humid-monitor (Google graph/chart design)

https://github.com/dalexgray/RaspberryPI_HTU21DF (Python HTU21DF drivers)

https://github.com/bpass03/RaspPi_HumidorMonitor (HTML/PHP/CSS design, Python MySQL integration, build components)

Initially, the project started with researching the advantages or disadvantages of building from the Arduino 
or Raspberry Pi platform.

Canakit Raspberry Pi 3 ($75)

Temperature/Humidity Sensor (HTU21D-F) ($15)

Five-Pin Flexcable (A9BAG-0508F-ND) ($2.50)

Edit this file to include the proper MySQL settings for your database

Edit this file with the file location for htu21df.py

Place this file in /etc/init.d/

This file will be called by the modified rc.local to start monitoring on boot

Edit and add the following line before exit 0 

Add sudo sh /etc/init.d/launch_htu21df.sh >> /root/htu21df.log & 

Initially, I had the sensor mounted on the rear wall of the humidor, with the cable run out the gap and the Raspberry Pi mounted on the 
outside rear of the humidor (basically, just on the other side of the wood from the sensor). However, the Raspberry Pi generated and 
transferred too much heat through the back side of the wood, and caused the sensor produce inaccurate readings (high temp, probably accurate, 
but excessively low humidity). 

I fixed this by reversing the pinout and flipping the sensor and mounting it to the lid of the humidor near where the humidifier and internal
hygrometer attach.