Each LED is tied to an if statement which is checking for different levels of humidity. As the target humidity is about to be reached, more LEDS are illuminated.

Scale:

Each different level in the chart shown above lights the corresponding number of LEDs on the LED bar graph.

In programming the device I used an Arduino library that can be found here: https://brainy-bits.com/blogs/tutorials/dht11-tutorial. This just makes the whole process faster and easier to read and make changes to.

All code can be found in the Details section of the project.