Mid Semester Presentation October 4, 2011

Team Members Duties: Real Time Clock Website Kevin Wellman Electrical Engineering Reginald Lott Adam Teague Matthew Adkins Duties: Power Circuit PCB Design Duties: User Interface Microprocessor Programming Duties: Sensors PCB Design Dr. Winton Faculty Advisor

Overview Problem Solution System Overview Constraints Technical Practical Improvements Systems Test PCB Enclosure SD2 Timeline References Questions

Problem Current residential sprinkler systems are inadequate in the following areas: Efficiency Ease of use Cost

Digital Sun S. Sense Add-on device Battery operated (sensors and control unit) $199 MSRP [1]

Cyber Rain XCI Requires internet access Weather reports cover general area $499 MSRP [2]

Solution Water Conserving Sprinkler Control Periodically monitors moisture content and temperature Operates on user-defined schedule Requires no external devices for modifying settings Costs less than $150

System Overview Microcontroller Moisture Sensor Temperature Sensor Power Supply Sprinkler Interface Real Time Clock

Physical Model

Technical Constraints Name Description Moisture Sensor Range The WCSC must be able to sense the volumetric water content of the soil from 20 to 50 percent. Outputs The WCSC must be able to output 24 V AC at 0.6A. Display The WCSC display must provide relevant information and options to the user, and it must be readable in well or dimly lit environments.

Technical Constraints (Cont.) Name Description Temperature Sensor Range The WCSC must sense temperatures from 20 to 50 degrees Fahrenheit. Voltage The WCSC must operate from a standard 120V wall outlet.

Practical Constraints TypeConstraintDescription EnvironmentalDurabilityThe device must be able to operate in harsh conditions. UsabilityCustomer Convenience The device must be easy to use and change watering schedule.

Environmental Sensors must withstand a variety of weather elements Heat Cold Water Resistant Control unit encasement durability Must be rugged enough to withstand incidental impact

Usability The unit must be simple to configure and operate. Water scheduling Time changes Display and Button Interface

Improvements RTC from breakout board to through hole mountable components AC/DC converter resized from 12VDC to 6VDC Implementation of PCB from Breadboard

Systems Test Testing of the systems will be completed after arrival of the PCB. Test will be conducted on the following components in this order: PCB Power supply Microprocessor LCD RTC Temperature Sensor Moisture Sensors Enclosure Entire System

Testing of Entire System Moisture (VWC) Current Moisture (VWC) Test 1 Moisture content greater than Moisture Setting Temperature greater than Temperature Setting Sprinkler should not operate Test 2 Moisture content less than Moisture Setting Temperature less than Temperature Setting Sprinkler should not operate Test 3 Moisture content less than Moisture Setting Temperature greater than Temperature Setting Sprinkler should operate

PCB

Enclosure

Timeline for SD2 AugustSeptemberOctoberNovember Hardware Refinement Software Refinement PCB Design PCB Populating Enclosure Testing

References: [1] Sprinkler Warehouse. [Online]. Available: Soil-Moisture-Sensors-s/7666.htm. [Accessed: January 18, 2011]. Soil-Moisture-Sensors-s/7666.htm [2] Beanworthy. [Online]. Available: 16Zone-Automated-Sprinkler-Controller/A/B000ZHTXEC.htm. [Accessed: January 18, 2011]. 16Zone-Automated-Sprinkler-Controller/A/B000ZHTXEC.htm [3] “VG400 Moisture Probe” [Online] Available:

Any Questions?