Process

I was certain that I want to sense the soil moisture level, so I built the sensor myself in the first week. I first built circuits with sensors (FSR and soil moisture sensor) and outputs (speaker and two LED light). I coded it so that it's blue with a rising tone when moisture, and red with a falling tone when dry. 

Then I altered the code so that dryness will result in non-stoping falling tones to harass users. I then realized that this constant reminder can be overwhelming and there should be a trigger to stop the sound when not desired. Nevertheless, an easy stop button will discourage people from watering their plants at the moment. So I set up the trigger as an FSR sensor, with LEGO components on it. In this way, one has to hit really hard on it to stop the sound but also hurting oneself with the bumpy LEGO. 

As the saying goes, you never win with violence. This device teaches people the lesson and reminds people to take care of plant properly, just as one may take care of their cats.