Low Cost Soil Moisture Monitoring System: A Capstone Design Project

Environmental monitoring is a significant driver for wireless sensor communication.Its potential to provide dynamic real-time data about monitored variable will enable to measure properties that have not previously been observable.A low cost consumer version soil moisture monitoring system was built using a gypsum block to take moisture readings, a peripheral interface controller (PIC) with a built-in transmitter as sensing unit, and a transmitter for wireless communication.The design of the overall system is based on: the system must provide consistent soil moisture measurements at low cost; the system must interface with an irrigation system to allow for automatic watering of the soil; and the measurement units must be unobtrusive to everyday activity.The system was tested so that it could be implemented with existing sprinkler systems.This system would conserve more water than the traditional timers that are in place on most irrigation systems today.In cases where the homeowner or user does a large amount of watering, there can be a substantial savings in water consumption with the low cost soil moisture monitoring system.While the prototype realizes all the goals that were set forth, the addition of other options would be beneficial to the marketability of the system.One option should be the implementation of other sensors such as a barometer and temperature sensor.These will allow the microcontroller to determine more accurately the optimum watering times.Also, reverting back to the original design that used a PIC with an integrated transmitter would reduce both the cost and the size of the sensing unit.While the current implementation works, a more user friendly interface, such as a PC interface, might be more desirable for some users.