Project

#	Title	Team Members	TA	Documents	Sponsor
39	Request for Approval: Soil Moisture Controller (Pitched Project)	First Yingyord Isabel Alviar Ren Yi Ooi	Dushyant Singh Udawat	design_document1.pdf design_document2.pdf design_document3.pdf final_paper1.pdf other2.pdf other1.pdf photo1.HEIC presentation1.pdf proposal1.pdf video
	This project is a pitched project idea by the U.S. Department of Agriculture’s research laboratory on campus. It would be performed in partnership with a capstone team from the Department of Agricultural and Biological Engineering. # Problem One of the biggest limiting factors for gains in agricultural productivity is the ability to provide sufficient moisture in the soil for the growth of crops. In particular, arid regions face the possibility of the occurrence of droughts that reduces the crop yields in dryland agriculture. To manage this issue, various water management strategies have been developed to ensure that there is sufficient water being applied over these crop lands. These irrigation systems have to provide control over the amount of water that is being applied over these crop lands such that optimal agricultural productivity is achieved while ensuring maximum water use efficiency. Currently, the measurement of soil moisture content in pots are performed manually with individuals monitoring the moisture level based on weight, or the use of gravimetric sensors. Upon irrigation, the weight or load of the pot would be at its maximum, and due to evapotranspiration over time, this weight would be lowered. When it eventually crosses a threshold set by the sensor, irrigation of the pots would be triggered again. However, due to the many different components that make up the weight of the pot, it is difficult to measure the exact proportion of increase in plant mass to the change in soil moisture content to obtain an accurate indication of when the irrigation has to be activated. As a result, there is a need for a more precise method to measure and maintain the soil moisture conditions in these pots through the use of soil moisture sensors. These soil moisture sensors would allow for the moisture that exists in the pot to be read so that sufficient irrigation is provided for consistent moisture. # Solution Overview Our solution consists of a cheaper yet more effective device that provides constant moisture monitoring and water irrigation as needed. When the moisture within the substrate is below the predetermined target level, the water valve will be triggered to an extent where the moisture can be maintained at that level. In addition, the users are also allowed to check the current status of each pot, that is whether the substrate moisture is desirable, and control the target level in the pot. We would work alongside the team of ABE students to also ensure that our solution could be scaled up for high-throughput of at least 50 plants in the future. # Solution Components ## Subsystem 1: Irrigation Subsystem Irrigation is the process of artificially applying controlled amounts of water to land or crops. This is done by using valves as well as a system of tubes and pumps to bring in water from pipes, canals, sprinklers, and other mean-made water sources, instead of relying on rainfall. For this project, the irrigation subsystem for each soil pot would consist of a valve that would open and close based on the moisture level measured, in order to maintain a desired set of moisture conditions for different soil and soilless substrate mixes. Irrigation is needed in a given pot if it is sensed that the moisture level falls below a certain value (for example, below 60 for fine soil). When this happens, relay switches activated by a microcontroller, such as an Arduino, will operate the irrigation valves (likely 24V) that correspond to each sensor-controlled pot, and water will flow out until the soil reaches an ideal value again. Potential materials: - ¾” valve: - https://www.amazon.com/Galcon-Irrigation-Reinforced-Greenhouse-Residential/dp/B08MTQB8BX/ref=sr_1_4?crid=3RHJI5FFG6PJE&keywords=24v+irrigation+valve+3%2F4+water&qid=1675117467&sprefix=24v+irrigation+valve+3%2F4+water%2Caps%2C113&sr=8-4 - https://www.amazon.com/Beduan-Electric-Solenoid-Normally-Colsed/dp/B07YTHKHL4/ref=sr_1_3?crid=2QMUSM9AGT0L8&keywords=24v%2Birrigation%2Bvalve%2B3%2F4&qid=1675117428&sprefix=24v%2Birrigation%2Bvalve%2B3%2F4%2Caps%2C100&sr=8-3&th=1 - Tubing: https://www.amazon.com/Tubing-Flexible-Hybrid-Lightweight-10-Feet/dp/B07HF648M5/ref=sr_1_4?keywords=clear+plastic+tubing&qid=1675117678&sr=8-4 - Hose ring: https://www.amazon.com/Selizo-Including-Adjustable-Clamps-Stainless/dp/B07G9TZLRM/ref=sr_1_8?crid=1C737TN4ANA1X&keywords=hose+ring&qid=1675117705&sprefix=hose+ring%2Caps%2C114&sr=8-8 ## Subsystem 2: Data Acquisition Subsystem The data acquisition subsystem will consist of a data logger, an instrument that monitors and records changes in conditions over time. Most data loggers can accept two or more types of input, so we would program ours to take inputs such as voltage, current, temperature, etc. The data logger will ultimately communicate the need for irrigation by measuring and recording calculated factors like volumetric water content for each soil, and generating a list of plants that require irrigation. Then, this list of plants will be sent to the microcontroller that carries out the irrigation process for the relevant plants by using a pulsing I/O signal of either 0 or 5V to communicate whether or not irrigation is needed. There are many expensive existing data loggers such as the CR100, but we would want to buy or build one that is still battery-powered and effective for a cheaper price. One option that nicely interfaces with an Arduino microcontroller would be to create a data logger from scratch using a data-logging shield, coin battery, and SD card. Potential materials: - Data-logging shield - https://www.amazon.com/AITRIP-Logger-Logging-Recorder-Arduino/dp/B09PDL7XM7/ref=sr_1_4?crid=13UWJYJNEUANV&keywords=data+logger+arduino&qid=1675121100&sprefix=data+logger+%2Caps%2C112&sr=8-4 - https://www.amazon.com/HiLetgo-Logging-Recorder-Logger-Arduino/dp/B00PI6TQWO/ref=sr_1_3?crid=13UWJYJNEUANV&keywords=data+logger+arduino&qid=1675121312&sprefix=data+logger+%2Caps%2C112&sr=8-3 - Coin battery for shield - SD card - www.adafruit.com ## Subsystem 3: User Interface Subsystem The user interface subsystem would consist of two main components. The first component would be an LCD display that shows the current soil moisture level as detected by sensors in a percentage form (out of 100%). The second component would be a dial in the form of a potentiometer for the user to be able to tune the soil moisture level to the desired level. This desired soil moisture level can also be displayed on the LCD screen. In order to achieve this, a customizable LCD display would be used. An Arduino Uno microcontroller can be used to interface the soil moisture sensors and potentiometer with the LCD display. Parts needed: - 16x2 LCD display (https://www.digikey.com/en/products/detail/newhaven-display-intl/NHD-0216BZ-FL-YBW/NHD-0216BZ-FL-YBW-ND/1701195) - Arduino Uno R3 ATMEGA328P Eval microcontroller (https://www.digikey.com/en/products/detail/arduino/A000066/1050-1024-ND/2784006) - 10K Ohms potentiometer (https://www.digikey.com/en/products/detail/bourns-inc/PDB12-H4301-103BF/PDB12-H4301-103BF-ND/3780664) - Breadboard (https://www.digikey.com/en/products/detail/dfrobot/FIT0096/1738-1326-ND/7597069) ## Subsystem 4: Controller Subsystem In order to efficiently gain the desired substrate moisture level, we decide to implement a PI controller which takes the feedback input from the moisture sensor, compares the measured value with the desired value, and triggers the water valve if the measured value is below the desired value. The value from both the moisture sensor and user input will be sent to a differential amplifier that outputs a voltage proportional to the voltage difference, and a diode that filters only the positive voltage difference i.e. when the desired moisture level is above the current level. The filtered voltage will then be inputted to the PI controller which consists of potentiometers for tuning the controller, inverting op-amps for amplification, and capacitors for implementing the integrator circuit. The reason we do not include a derivative part is to remove the instability problem which may arise from a noisy system. Finally, the output of the controller will be amplified and connected to a LM555 Timer chip in order to generate a PWM signal to the water valve so that the amount of water being given is sufficient to each pot. Please note that further experimentation is still needed to determine the specific parts within each component. # Criterion for Success - The moisture sensors should be able to detect the current level of moisture in the soil for the moisture level data to be logged and displayed on a monitor - The system should be able to provide irrigation when the moisture level falls beyond a set threshold level - There should be a dial that allows the user to tune the moisture level to a desired value

Habit-Forming Toothbrush Stand

John Kim, Quinn Palanca, Rahul Vasanth

Habit-Forming Toothbrush Stand

Featured Project

I spoke with a TA that approved this idea during office hours today, and they said I should submit it as a project proposal.

# Habit-Forming Toothbrush Stand

Team Members:

- Rahul Vasanth (rvasant2)

- Quinn Andrew Palanca (qpalanc2)

- John Jung-Yoon Kim (johnjk5)

# Problem

There are few habits as impactful as good dental hygiene. Brushing teeth in the morning and night can significantly improve health outcomes. Many struggle with forming and maintaining this habit. Parents might have a difficult time getting children to brush in the morning and before sleep while homeless shelter staff, rehab facility staff, and really, anyone looking to develop and track this habit may want a non-intrusive, privacy-preserving method to develop and maintain the practice of brushing their teeth in the morning. Keeping track of this information and but not storing it permanently through a mobile application is something that does not exist on the market. A small nudge is needed to keep kids, teenagers, and adults of all ages aware and mindful about their brushing habits. Additionally, many tend to zone out while brushing their teeth because they are half asleep and have no idea how long they are brushing.

# Solution

Our solution is catered toward electric toothbrushes. Unlike specific toothbrush brands that come with mobile applications, our solution applies to all electric toothbrushes, preserves privacy, and reduces screen time. We will implement a habit-forming toothbrush stand with a microcontroller, sensors, and a simple LED display that houses the electric toothbrush. A band of sensors will be wrapped around the base of the toothbrush. Lifting the toothbrush from the stand, turning it on, and starting to brush displays a timer that counts seconds up to ten minutes. This solves the problem of brushing too quickly or losing track of time and brushing for too long. Additionally, the display will provide a scorecard for brushing, with 14 values coming from (morning, night) x (6daysago, 5daysago, . . . , today) for a "record" of one week and 14 possible instances of brushing. This will augment the user's awareness of any new trends, and potentially help parents, their children, and other use cases outlined above. We specifically store just one week of data as the goal is habit formation and not permanent storage of potentially sensitive health information in the cloud.

# Solution Components

## Subsystem 1 - Sensor Band

The sensor band will contain a Bluetooth/Wireless Accelerometer and Gyroscope, or Accelerometer, IR sensor (to determine height lifted above sink), Bluetooth/Wireless connection to the microcontroller. This will allow us to determine if the electric toothbrush has been turned on. We will experiment with the overall angle, but knowing whether the toothbrush is parallel to the ground, or is lifted at a certain height above the sink will provide additional validation. These outputs need to be communicated wirelessly to the habit-forming toothbrush stand.

Possibilities: https://www.amazon.com/Accelerometer-Acceleration-Gyroscope-Electronic-Magnetometer/dp/B07GBRTB5K/ref=sr_1_12?keywords=wireless+accelerometer&qid=1643675559&sr=8-12 and individual sensors which we are exploring on Digikey and PCB Piezotronics as well.

## Subsystem 2 - Toothbrush Base/Stand and Display

The toothbrush stand will have a pressure sensor to determine when the toothbrush is lifted from the stand (alternatively, we may also add on an IR sensor), a microcontroller with Bluetooth capability, and a control unit to process sensor outputs as well as an LED display which will be set based on the current state. Additionally, the stand will need an internal clock to distinguish between morning and evening and mark states accordingly. The majority of sensors are powered by 3.3V - 5V. If we use a battery, we may include an additional button to power on the display (or just have it turn on when the pressure sensor / IR sensor output confirms the toothbrush has been lifted, or have the device plug into an outlet.

# Criterion For Success

1. When the user lifts the toothbrush from the stan and it begins to vibrate (signaling the toothbrush is on), the brushing timer begins and is displayed.

2. After at least two minutes have passed and the toothbrush is set back on the stand, the display correctly marks the current day and period (morning or evening).

3. Track record over current and previous days and the overall weekly record is accurately maintained. At the start of a new day, the record is shifted appropriately.

Project Videos

Habit Forming Toothbrush Stand