Category: Team status reports

What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

The main risks are related to connections (solders breaking, sensors disconnecting). We are reinforcing our connections and using JHT connectors instead of soldering the sensors directly to a protoboard.

Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

No

List all unit tests and overall system test carried out for experimentation of the system. List any findings and design changes made from your analysis of test results and other data obtained from the experimentation.

Capacitance test – We learned that the capacitance between different liquids didn’t change much, so we needed to use different metrics for classification.

Unit tests for temperature, tds, turbidity, and color sensors with different liquids. We found good variability between color, tds, and turbidity in our target liquids. We also found that the temperature sensor is consistent with what we expected.

Integration tests for the sensors once the system had been assembled – we tested the sensors in the bottle, and found the results from the unit tests remain.

Level testing for the ultrasonic testing – we tested that the level indicated by the ultrasonic sensor is consistent with the expected value. We also found that this could be used as a metric for bottle stability, and decided to use this instead of FSR’s. This allowed us to simplify our system and decrease energy expenditure.

Static code analysis for the Arduino code and JS code. Issues found (such as unreachable code and uninitialized values) were either mitigated or found to be false positives.

Connection test – we tested the connection between the app and the bottle, and found it to be stable.

What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

We had a few issues with fabrication, wires breaking, sensors disconnecting, and fitting the assembly in the bottom compartment. We resoldered our assembly, with a much more reinforced structure, and are printing a slightly taller bottom compartment.

Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

We moved away from a pressure plate and to an FSM based on the ultrasonic sensor to measure bottle stability. This will simplify the system, reduce weight, and slightly decrease power expenditure.

Updated schedule:

What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

Right now, we are concerned with finding a food-safe, effective sealant. We are exploring a few different options. The first one has already arrived, and we will begin testing shortly. We are also working on detecting uprightness with an FSR, and are exploring different alternatives for this (more than one FSR, a larger FSR, different stands to hold the FSR in the final bottle).

Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

Our exploration into sealants and FSR options does have a cost, but we have room in the budget for them.

Another big change is that we decided to 3D-print our bottle (out of food-safe acrylic), so we have purchased filament for it, but, again, there is room in the budget for it.

Now that you have some portions of your project built, and entering into the verification and validation phase of your project, provide a comprehensive update on what tests you have run or are planning to run. In particular, how will you analyze the anticipated measured results to verify your contribution to the project meets the engineering design requirements or the use case requirements?

We will measure the sensors (temperature, turbidity, tds) against the ground truth (from reference tables and/or pre-existing sensors we know to be correct), to make sure they are within an acceptable margin of error in the final assembly.

We will use fuzzers and static analysis tools to detect issues in the code and correct them (both for the microcontroller code and the app code)

We will stress-test the bottle for leakage by leaving liquid in it for an extended period of time, and moving it at intervals (the acceptable threshold is no leakage).

We will test the battery life by keeping the bottle on for extended periods of time, and simulating drinking from it at intervals (we expect to reach the battery life outlined in our requirements, of at least 2 days).

We will test the classifier for accuracy with different samples, as we calibrate the system for them.

What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

We are working on integration, and the two main issues right now are fitting all the needed components into the bottle’s bottom chamber and detecting density and uprightness. For fitting all components, we are shortening wires as much as possible, and looking into fabricating a larger chamber.

For density and uprightness, we noticed that we couldn’t attach our pressure sensor directly to the bottom of our bottle, since it is slightly indented and the sensors are somewhat fragile when bent. Thus, we plan on fabricating an adapter (as was suggested to us in the weekly meeting) to improve that. We may need more pressure plates to work on this.

Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

We will need to purchase more pressure plates, but that is well within the budget; similarly, we plan on fabricating the adapter for the sensor and a larger bottom compartment, but we have access to printers we can use at no cost.

Here’s the bottle, with mounted sensors, that we assembled this week and will use for our interim demo:

• What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

The largest issue we currently have is that our waterproof ultrasonic sensor does not work. We believe the unit we received is defectful. We purchased a new one, and also purchased RS485 modules to test with a sensor we have, that requires this part to work. Another issue is that the difference of capacitance between liquids is not as large as we expected. We will try to use it as a dimension in classification, but we also have turbidity as an alternative metric to test.

• Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

We are considering adding a turbidity sensor, to increase classification accuracy, either instead of, or in addition to, capacitance. We also purchased a new ultrasonic sensor and RS485 modules, as the sensor we were testing does not seem to work. We have room in the budget for these new parts, but we will also try to return the sensor that does not work to receive that money back.

• What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

The main issue we found is that the waterproof ultrasonic sensor we were using was not working as expected. We discovered that this is because it communicated using the Rs485 protocol, and we need an adapter for it to work with the arduino boards, leading to added space, power consumption, and engineering complexity. The order for our contingency plan – a photoelectric water level sensor – had some issues, did not arrive, and needed to be reordered. It should arrive sometime next week, and we will test it as soon as we receive it. We also purchased a sensor that does not require an adapter. In the meantime, we are testing for our proof-of-concept with a non-waterproof ultrasonic sensor.

• Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

We are considering changing the ultrasonic sensor for a photoelectric sensor. We also purchased a new waterproof ultrasonic sensor. We have room in the budget for it, but it can be returned (within 30 days)  if we deem the photoelectric sensor adequate.

Please write a paragraph or two describing how the product solution you are designing will meet a specified need…

Part A (Erin): with consideration of global factors. Global factors are world-wide contexts and factors, rather than only local ones. They do not necessarily represent geographic concerns. Global factors do not need to concern every single person in the entire world. Rather, these factors affect people outside of Pittsburgh, or those who are not in an academic environment, or those who are not technologically savvy, etc

The smart water bottle we are proposing will remind people to drink more water and help them meet their intake goals. A smart water bottle like Aqualotol can benefit everyone in the world but more so people in first and second world countries due to the cost of the water bottle. This bottle is also better for people with smart phone access since it will allow them to use the full feature set of the bottle. People who are not good with technology will still be able to use our intuitive UI in the phone app to track their water consumption level. This bottle is meant for anyone who has a smart phone and can afford the bottle. Although this may seem limited, 68% of the world owns a smart phone and many may want to buy the bottle.

Part B (Alan): with consideration of cultural factors. Cultural factors are encompass the set of beliefs, moral values, traditions, language, and laws (or rules of behavior) held in common by a nation, a community, or other defined group of people.

It has been concluded that the majority of Americans do not drink enough water each day [1] . The current culture, where people have very busy lifes, is, reasonably, one of the factors that impedes people from hitting their water drinking goals. This water bottle, as it is designed to be carried throughout the day, will help people incorporate more water drinking into their routines, helping in the mitigation of this issue. This effect will be further enhanced by the tracking of the amount of water drank, the reminders sent when the user hasn’t been drinking enough, and the social media hydration-streak tracking, allowing friends of the user to remind them to drink more water. Thus, our project can help improve water consumption among Americans, incentivizing healthier habits and reducing the health issues that stem from insufficient water consumption.

Sources:

1-https://civicscience.com/forty-seven-percent-of-americans-dont-drink-enough-water-plus-more-h2o-insights/

Part C (Matt): with consideration of environmental factors. Environmental factors are concerned with the environment as it relates to living organisms and natural resources.

The aqualotl project takes into account major environmental factors, since it is a smart and refillable water bottle. Plastic water bottles litter the ocean, and are harmful to the environment, causing the deaths of the unfortunate sea creatures who happen to stumble upon them. In fact, 500 billion plastic water bottles are being used each year, but at least 250 billion of it isnt properly recycled, and is usually littered and it is estimated that around 9 million tons of plastic waste is dumped into the ocean per year. We hope that our bottle will help promote reusable water bottles, instead of one time usage ones that several consumers are accustomed to today, as well as reducing the need for people to litter the environment.