Based on Roald Dahl's The Sound Machine short story, this Arduino machine will let you "hear" plant mood according to soil moisture.
Even when sounds of course do not come from the plants but from MP3 recordings, the experience results revealing and lets you be conscience about plants being alive and the suffering from water deprivation.
I've used an Arduino Nano, FC28 sensor, 7 segment display, a button, a 4ohm speaker, DFPlayer MP3 player, a microSD card and a custom case.
The code will check button status and when button is pressed it will read FC28 sensor, analog values will be mapped to 0-100 percentage scale, the percentage will be printed in the 7 segment display and a custom recording will be played according to the moisture percentage. For example: screams when moisture is less than 30%, giggles when moisture is greater than 75%, etc
Complete source code can be downloaded from https://github.com/ronibandini/TheSoundMachine
Files for 3D-printed can be downloaded from https://www.thingiverse.com/ronibandini/designs