3171 Instrumentations Extra Credit

Caleb Harvey

Demetric Davis

Elan Weinberg

The circuit configured in this project utilizes a cell phone app (Particle) to control a water pump through the application of a Particle Photon, switch, servo motor, and 120V from the nearest outlet. The triggering component of this project (the servo motor and the switch) are held together using duct tape. The following list indicates what all this project utilizes:

Purchased

  • Particle Photon ($30)
  • Breadboard (included in above price)
  • Servo Motor – Radioshack Micro Servo ($12)
  • Switch – Radioshack SPDT Switch w/ Roller Lever ($4)
  • Pond Water Pump – Intertek WPR2000 (Retail $150, already possessed)

Not Purchased

  • 120v standard outlet
  • Particle cell phone app
  • Wires

The visual represents the collaborated circuit as seen on a basic level. When the code is activated via the cell phone app, it sends a signal (via Wi-Fi) to the Particle Photon. The Photon then activates the servo motor which in turn operates the roller switch. With the switch off (open), no current is flowing and the water pump is off, but with the switch on (closed, which is shown in the diagram), the pump is powered on. Since the Particle Photon cannot operate at 120v, there is a stepdown transformer to convert the standard 120v to a useable 5v.

Shown to the left is the wiring of the Particle Photon to the servo motor. The stepdown transformer output (5v) is fed to the Particle Photon via a microUSB cable.

This pump and circuit are to be used by Caleb at his home. The design arose from a problem with the pond pumps constantly running, thus causing failure at a faster rate. With this design, the pump will run roughly half as long as it normally would (12hr vs. 24hr/day), this cycling will increase the pump life by an estimated 2x, from 2 years to 4, saving about $37.50 per year based on a $150 pump cost. The power saved would me on the order of 576,840 Watt-hours per year and based on Duke Energy’s rate (9.3581 cents/kWh), this design will save $53.14 per year.

Altogether, this design could possibly save about $90 per year or more, depending on pump use and life. With a parts cost of $46, it would technically pay for itself in 6 months.

The first apparent downside to this design are that it cannot be used outside of Wi-Fi range, or else the signal cannot be sent from the Particle app to the Photon. The second downside is that the electrical components are not weatherproof (except for the pump), so the whole circuit must be kept inside with a long wire running to the pump.

The foremost design improvement that can be made is the weatherproofing of all circuitry and components via a case, though a long wire will still need to be run to supply power. Long weatherproofed extension cords are easy to come by and bury out of sight. Using the IFTTT app, a code could also be made to control the pump via the time of day, turning the pump on only for the hours that see sunlight, the major upside to this would be that the operation could be completely hands-free.

For a basic design, this system is very effective. We all learned quite a bit doing this project, including but not limited to: a better understanding of real-world microcontroller applications, Particle Photon code, and servo motors and their uses.

Included on the following pages are snips of the Particle Photon code.