Humidity Controller

thingiverse

This is an Arduino Uno-based humidity controller designed for small grow rooms or tents, but it can be used in any room of your house. In addition to controlling a humidifier, it will calculate the Vapor Pressure Deficit, which is useful for growing and maintaining healthy plants. The documentation provides more details on how this works. The documentation and Arduino sketch are contained in zipped folders for easy access. This controller was designed to work with an inexpensive vaporizer like the Vicks Warm Steam Vaporizer. The case has a location for adding a real-time clock if desired, but I haven't written any code for that yet. * Update: I'm currently using this area to give it WiFi capability with an ESP8266 (ESP-01) and adapter board. The existing case design can still be used if the separator is cut or broken out, but I'm enlarging this space to make room. * I've got the Arduino code working so you can view Air Temperature, Humidity, Leaf Temperature, and Vapor Pressure Deficit using any web browser without needing an internet connection. * I'm also working on a program for Windows that lets you view and log downloaded values using its own built-in browser. 4/22/2020 I had a hard drive crash while working on the sketch, and I'm in the process of updating my backup to what I had before the crash happened. * End of update In addition to an Arduino Uno, you'll need an LCD/Keypad Shield, a Solid State Relay rated at least 10 amps and higher than your mains voltage. The SSR must have a DC input and AC output. A mechanical relay can be used instead, but it's recommended that the #define PIDCONTROL line be commented out so On/Off control is used instead of PID to increase the lifespan of the relay. There are two versions of the DHT11 sensor case: one for use with the DHT11 supplied with some Arduino kits and a circuit board designed for multiple items. Mine was a Rex Qualis kit. This is my first original Arduino project, so I apologize in advance if the code isn't up to professional standards yet. The faceplate and buttons for this project were adapted from the configurable case by Egil on Thingiverse at https://www.thingiverse.com/thing:845415