Plant Pulse

Kaylie Ching, Clara Huang, Shivreet Dhillon

Overview

PlantPulse is intended to be a custom capacitive moisture sensor, powered by a single cell lipo battery, with a regulating charge circuit. The ESP32 on the board also serves to automatically water the plant once the moisture in the soil is read as lower than a calibrated threshold. The bottom half of the board is stuck into the soil, wherein the copper trace serves as one side of a capacitive plate. Once a DC voltage is sent through the RC circuit connected to the copper trace, the change in capacitance can be measured as a function of the voltage drop across the plant. So that the board can be modular and used in any location in the household, a battery charging circuit was implement using two ICs and a dropout regulator to drop the 5V USBC connection to the 3V ESP32.

Breadboarding our idea

IMG_8371.mov

Schematic

Front and Back Copper Layout

Challenges


Although we weren't able to properly debug our board and get to a stage where calibration and , we learned a great deal about PCB design & assembly, and got a change to implement the more theoretical electronics knowledge accumulated in previous classes.