Table of Contents
- Team Vision for Detailed Design Design Phase
- Sensor Testing
- Arduino Chip Schematic
- Bill of Materials
- Test Plans
- Summer Feasibility Testing
- Risk Assessment
- Plans for the Next Phase
- Purchasing Plans
Team Vision for Detailed Design Phase
- How are we planning on testing this summer?
- What needs to be purchased before the summer?
- How do we want to organize our work, so we know what we're doing when we get back from break?
- How can the team help Quinn with the code?
- How can we test the sensor's ranges and accuracies?
- Which microcontroller best fits our needs?
- How will we store data from the microcontroller?
- What is the best power option based on the selected microcontroller?
The soil moisture sensor was tested by measuring the moisture of soil that had been dried out in a furnace so that the moisture was known to be zero percent, which the sensor read correctly. It was also tested using very wet soil, which gave a reading similar to putting it in water, an expected result based on the consistency of the soil.
Thanks to Shwe Win in the Golisano Institute for Sustainability for allowing us to make use of the oven to dry the soil sample.
Arduino Chip Schematic
Bill of Material (BOM)
Summer Feasibility Testing
Over the summer, we are planning on performing a feasibility test of a preliminary prototype. For this, we have dug a pit with a diameter of 20 -24 inches and a depth of 40 inches or 1.016 meters. The temperature and soil moisture sensors will both be placed in the pit and connected to the microcontroller chip. The wire connections will be fed through a hose for water proofing; a sealed hole in the container will allow the wires to enter the container.
Rather than using the entire Arduino Uno board, only the chip, the AT Mega 328p-PU, will be utilized in order to save power, which is something we believe may be an option in the final product. For the feasibility testing, a breadboard will be used for all of the connections to the chip and a 9 volt battery will provide the power for the test period.
Though further testing of the motion sensor that will be used to count the use is required, it will not be a part of the feasibility testing over the summer. The team agrees that it is not as important to test the motion sensor in the simulation and time is running short to complete the prototype and install the module at the test site. The temperature and soil moisture sensors both require more testing in the pit to ensure their durability, while the motion sensor will be less exposed and require less testing in this respect.
Over the summer our guide, who graciously offered his yard for the test, will follow a given script and add things to the pit, such as water, to provide a full range of conditions for the test. A log will be kept of everything that is done to the pit. The weather will also be monitored.
Update on May 22, 2016
During the gate review on May 18,2016, the summer test system was completed for installation. The test plans can be found at the following link: Feasibility Test Plans.
- Pit depth = 3' 3" (measured)
- Top of water to top of pit = 2' 0.5" (measured)
- Water depth = 2' 2.5" (calculated)
- Approximately 1.25 buckets* of dog feces
- 2 buckets of cut grass
- *will add volume of bucket once measurements of it are obtained
- The wires of the enclosure were rolled up with tape to organize them
- The battery packs were taped together in a staggered formation so the on/off switches could be accessed on all of them
- For water proofing on the end cap, Kwik Seal Plus caulk was used in the holes around the sensors
- The caulk needed to dry for 24 hours, so Mr. Hanzlik would install the system the next day (May 19th, 2016)
- The system would be installed such that the pit sensors only reached the water level and were not completely submerged
Room for Future Improvement:
- Determine if the wire direction can be changed on the moisture sensor so they do not run into the conduit wall
- Be sure not to underestimate the required time in the future
- Make sure everything fits in the enclosure earlier on
- Create something to run the wires through the conduit more easily
Plans for next phase
- Evaluate summer testing to see if the design is feasible.
- How does the temperature affect the reliability of the motion sensor?
- Will one sensor failing affect the entire system?
- Can the battery and SD card be separate from the microcontroller module for easy access?