IN THIS PROJECT I’LL INTRODUCE A NEW TYPE OF ANALOG SENSOR THAT DETECTS MOISTURE LEVELS. YOU’LL SET UP A LIGHT AND SOUND ALARM SYSTEM TO TELL YOU WHEN YOUR PLANT NEEDS WATERING.
• Arduino board
• Jumper wires
• HL-69 hygrometer soil moisture sensor
• Piezo buzzer
You’ll use an HL-69 moisture sensor, readily available online for a few dollars or from some of the retailers listed in Appendix A. The prongs of the sensor detect the moisture level in the surrounding soil by passing current ...