Wireless Soil Moisture Sensor- University of Calgary

Our team of 7 engineering students at the University of Calgary are developing a wireless soil moisture sensor for farms.

Problem:

Agricultural irrigation in Alberta uses a total of 216 000 000 L of water each year, at an average cost of $1375.23/ML. This equates to agriculture in Alberta spending close to $300 000/year on water for irrigation. There is also a substantial cost to power the pumping infrastructure in most irrigation systems, which is not accounted for in the above value. Evidence suggests that current irrigation practices in southern Alberta are not meeting optimum plant growth requirements. Agriculture practices have been found to be conservative in water usage. Sites tend to under-irrigate more commonly, with less than 7% of sites being found to over-irrigate. Currently, farmers lack the resources to know the precise moisture conditions of their fields for control of irrigation. Increases in global temperature will likely increase the moisture needs of crops in Alberta, while other parts of the world are already experiencing significant water resource challenges. If trends continue, some sites will continue to under-irrigate their crops, limiting their maximum yields. Others will continue to over-irrigate their crops, leading to water waste and unnecessary costs.

Solution:

A soil moisture controlled irrigation system to provide crops with water when they need it and conserve it when moisture levels are sufficient. The system consists of devices (nodes) which can be distributed around farms and placed in each irrigation zone to monitor specific moisture conditions. The nodes will communicate to a central gateway at timed intervals using wireless communication. If a crop needs water, the user will be notified to commence irrigation. Sprinklers will be triggered and the moisture level will be monitored. The sensors will notify the user when moisture levels are adequate. The users will be able to track soil moisture data through an easy to use app or web page with the location of each node indicated. By controlling irrigation with real time moisture level data, our system will help users improve their crop yield and maximize profit.

Technical Details:

The diagram above shows how the sensor nodes will communicate to the user application.

For the hardware side of the project, the sensor nodes will consist of:

-Battery

-Microcontroller

-Radio Transceiver Module

-Moisture sensor analog conditioning circuity

The gateway is custom-designed, with the following components:

-Processor (running Linux)

-Radio Transceiver

-WiFi Module

-Power Supply

In order to measure the soil moisture with the accuracy required for agriculture, we are designing a custom probe structure for the sensor. We have designed an analog control/ monitoring circuit that interfaces with the microcontroller.

There will be several PCB's in the first prototype. One for the radio/ microcontroller/ battery and another for the sensor circuitry, and another for the gateway. We are currently in the process of building our first prototype and are funding this project ourselves, so any help we can get would be greatly appreciated! We are planning to build our first set of PCB's within the next 2 weeks, so we can begin validating the design. If PCBWay will sponsor our project, we will mention your company at our end-of-year design project where we will showcase the project to students, professors, and industry. Thank you!