Project

# Title Team Members TA Documents Sponsor
73 Circle of Life: Automated Desktop Aquaponics System
 Aishwarya Manoj
Anjali Aravindhan
Estela Medrano Gutierrez
 Manvi Jha design_document1.pdf
final_paper1.pdf
photo1.jpg
photo2.jpg
photo3.png
photo4.png
presentation1.pdf
proposal1.pdf
video
# Circle of Life: Automated Desktop Aquaponics System

# Team Members:
- Aishwarya Manoj (am133)
- Anjali Aravindhan (anjalia2)
- Estela Medrano (estelam2)

# Problem

Urban living and limited indoor space make it difficult for individuals to grow fresh produce sustainably. Aquaponic systems offer an efficient solution by combining fish cultivation and plant growth in a closed-loop ecosystem, but existing systems require frequent manual monitoring and maintenance. Current desktop-scale aquaponics kits often lack intelligent control features and are cost-prohibitive for individual users.

# Solution

This project proposes the design and construction of a small desktop smart aquaponics system integrating automated environmental and fluid control. The system consists of a compact fish tank and plant grow bed forming a closed-loop water circulation path. An electronically controlled pump circulates water between the tank and grow bed, while a motorized dispensing mechanism provides automated fish feeding. A programmable grow-light module delivers controlled lighting cycles for plant growth. Embedded sensors monitor key system conditions such as water flow, ph level and water temperature. A microcontroller schedules feeding and lighting and processes sensor data. Depending on budget and difficulty, we may add more or less capabilities.

# Solution Components

## Subsystem 1: Fish Feeder Subsystem

A simple automated fish feeder will be implemented using an SG90 servo motor (linked below) operating between two angular positions, one away from the fish tank and another towards the fish tank for dispensing food. A custom 32-printed food container will be mechanically coupled to the servo shaft using screws and will include a small outlet opening that allows food to dispense when the container is rotated downwards. The servo motor will be controlled via PWM signals generated by a microcontroller. This microcontroller will also serve as the controller for the other subsystems.

[https://www.digikey.com/short/0r42n3vv](url)

## Subsystem 2: Lighting Subsystem

The lighting subsystem serves as the artificial light sources for plants in our desktop aquaponics system. The purpose of this subsystem is to make sure plants will get the correct amount of light and intensity per day to simulate growth due to sunlight from the Sun. The lighting subsystem will use LED colored lights with alternating blue and red colors to simulate sunlight and promote photosynthesis. We plan on using the Royal Blue and Deep Red ASMW-LL00-NKM0E LEDs from DigiKey (also linked below this section) connected to a LED driver to both control the lighting system and step down the input voltage of the PCB to the 3.08V needed by the lights. This LED driver will be in the same PCB as the microcontroller system and will use the same microcontroller. It will be mounted above the plants and the aquarium portion of the aquaponics system and shine down upon the plants.

[https://www.digikey.com/short/zcmqv3wj](url)

## Subsystem 3: Water Quality Subsystem

This subsystem monitors water quality through various sensors and allows for us to ensure that the aquaponic system is working properly. The three main components of this subsystem are the water flow sensor (314150005 from DigiKey), the water PH sensor (SEN0161 from DigiKey), and the water temperature sensor (Waterproof 1-Wire DS18B20 Digital temperature sensor) As we have a water pump pushing water up through our aquaponic system and bringing water to the plants above the fish tank, we need to measure the flow rate of the water to ensure that this component is operating effectively. The water flow sensor will thus measure the flow of water and ensure that the water is pumping effectively up the system. Alongside this, we will have a PH sensor to measure the PH of the water, which is critical for the health of both the fish and the plants. As we aim to have beta fish in the tank, that requires a PH of roughly 6.8 to 7.5, and we will have plants that require that slightly acidic to neutral PH range as well. If the PH is outside of this range, we will have a LED indicator (sourced from our component kit) so that the user knows it is time to change the water. Finally, we will have a sensor measuring the temperature of the water to ensure that it is habitable for the fish. Again, for beta fish this requires a temperature of 76 to 85 degrees Fahrenheit. The temperature sensor will measure the temperature of the water in the tank and if it is too high or too low, an LED indicator will be triggered, allowing the user to change the water or the temperature of their room.

[https://www.digikey.com/short/r7f95h7j](url)

[https://www.adafruit.com/product/381?srsltid=AfmBOop4JLBfv5qedUGq36frDQX9vyVTusMKieUlSaGwtCNAFJlJTlm4](url)

[https://www.digikey.com/short/v9btn5d9](url)

## Subsystem 4: Power Subsystem

The power subsystem’s main goal is to provide power to the other subsystems in this project, including but not limited to the lighting, fish feeder, water quality, and pump. To start the project will need an AC to DC 12V converter that is linked below. The voltages of the components will be the following:
- The microcontroller unit, either a STM32- or a ESP32-class IC, requires 3.3 volts. For example, a STM32G4/F4 or a ESP32-S3.
- The LEDs require a voltage of 3.08V and 200mA.
- The water flow rate sensor requires an input voltage of at least 5V.
- The PH sensor also requires an input voltage of 5V. The water temperature sensor’s power is between 3.0V to 5.5V.
- The circulation pump ranges from 6V to 18V.
- The water feeder servo uses 5V.
Thus, we will be using a voltage regulator to step down the voltage from 12V to 5V for all of the systems, and a LDO to step it down to 3V for the LEDs.

[https://www.digikey.com/short/dbfnfn48](url)

[https://www.digikey.com/short/bf0mqfjh](url)

[https://www.amazon.com/12V-Power-Supply-Adapter-Transformer/dp/B07DMFN2YN](url)

## Subsystem 5: Water Pump Subsystem

The water pump will be in series with the water flow sensor, sending the water from the fish tank up to the plants. We will be using a FIT0563 circulation pump that is waterproof, and depending on the water flow sensor’s outputs, we will be controlling the speed of the circulation pump by PWM modulating the supply voltage using a MOSFET.

[https://www.digikey.com/short/cr79t182](url)

# Criterion For Success

- The pH sensor accurately measures the pH
- The temperature accurately measures the temperature of the water
- The flow rate sensor accurately measures the flow rate
- Water is able to flow in a circular loop from the aquarium to the plants and vice versa
- Automated fish feeder is able to supply food into the fish tank once every 24 hours
- Lighting is able to mounted above the plants and has daily lighting schedule that changes based on the time of day (24 hour schedule implemented)
- The LED indicators accurately indicate temperature that is too cold or warm, and water that has a PH too high or low (unsafe for fish)

RFA: Any-Screen to Touch-Screen Device

Ganesh Arunachalam, Sakhi Yunalfian

Featured Project

# Any-Screen to Touch-Screen Device

Team Members:

\- Sakhi Yunalfian (sfy2)

\- Muthu Arunachalam (muthuga2)

\- Zhengjie Fan (zfan11)

# Problem

While touchscreens are becoming increasingly popular, not all screens come equipped with touch capabilities. Upgrading or replacing non-touch displays with touch-enabled ones can be costly and impractical. Users need an affordable and portable solution that can turn any screen into a fully functional touchscreen.

# Solution

The any-screen-to-touch-screen device uses four ultra-wideband sensors attached to the four corners of a screen to detect the position of a specially designed pen or hand wearable. Ultrawideband (UWB) is a positioning technology that is lower-cost than Lidar/Camera yet more accurate than Bluetooth/Wifi/RFID. Since UWB is highly accurate we will use these sensors to track the location of a UWB antenna (placed in the pen). In addition to the UWB tag, the pen will also feature a touch-sensitive tip to detect contact with the screen (along with a redundant button to simulate screen contact if the user prefers to not constantly make contact with the screen). The pen will also have a gyroscope and low profile buttons to track tilt data and offer customizable hotkeys/shortcuts. The pen and sensors communicate wirelessly with the microcontroller which converts the pen’s input data along with its location on the screen into touchscreen-like interactions.

# Solution Components

## Location Sensing Subsystem (Hardware)

This subsystem will employ Spark Microsystems SR1010 digitally programmable ultra-wideband wireless transceiver. The transceiver will be housed in a enclosure that can be attached to the corners of a screen or monitor. Each sensor unit will also need a bluetooth module in order to communicate with the microcontroller.

## Signal Processing Subsystem (Hardware and Software)

A microcontroller, specifically the STM32F4 series microcontroller (STM32F407 or STM32F429). Real-time sensor data processing takes away a considerable amount of computing power. The STM32F4 series contain DSP instructions that allow a smoother way to perform raw data processing and noise reduction. This subsystem will allow us to perform triangulation to accurately estimate the location on the screen, smooth real-time data processing, latency minimization, sensitivity, and noise reduction.

A bluetooth module, in order for the sensor to send its raw data to the microcontroller. We are planning to make the communication between the sensors and the pen to the microcontroller to be wireless. One bluetooth module we are considering is the HC05 bluetooth module.

The microcontroller itself will be wired to the relevant computer system via USB 2.0 for data transfer of touchscreen interactions.

## Pen/Hand Wearable Subsystem (Hardware)

The pen subsystem will employ a simple spring switch as a pen tip to detect pen to screen contact. We will also use a Sparkfun DEV-08776 Lilypad button to simulate a press/pen-to-screen contact for redundancy and if the user wishes to control the pen without contact to the screen. The pen will also contain several low profile buttons and a STMicroelectronics LSM6DSO32TR gyroscope/accelerator sensor to provide further customizable pen functionality and potentially aid in motion tracking calculations. The pen will contain a Taoglas UWC.01 ultra-wideband tag to allow detection by the location sensing subsystem and a bluetooth module to allow communication with the microcontroller. The unit will need to be enclosed within a plastic or 3D printed housing.

## Touch Screen Emulation Subsystem (Software)

A microcontroller with embedded HID device functionalities in order to control mouse cursors of a specific device connected to it. We are planning to utilize the STM32F4 series microcontroller with built in USB HID libraries to help emulating the touch screen effects. We will also include a simple GUI to allow the user to customize the shortcuts mapped to the pen buttons and specify optional parameters like screen resolution, screen curve, etc.

## Power Subsystem (Hardware)

The power subsystem is not localized in one area since our solution consists of multiple wireless devices, however we specify all power requirements and solutions here for organization purposes.

For the wireless sensors in our location sensing subsystem, we plan on using battery power. Given the UWB transceiver has ultra-low power consumption and an internal DC-DC converter, it makes sense to power each sensor unit with a small 3.3V 650mAh rechargeable battery (potential option: [https://a.co/d/acFLsSu](https://a.co/d/acFLsSu)). We will include recharging capability and micro usb recharging port.

For our pen, we plan on using battery power too. The gyroscope module, UWB antenna, and bluetooth module all have low-power consumption so we plan on using the same rechargeable battery system as specified above.

The microcontroller will be wired via USB 2.0 directly to the computer subsystem in order to transmit mouse data/touchscreen interaction and will receive 5V 0.9A power supply through this connection.

# Criterion For Success

## Hardware

The UWB sensor system is able to track the pens location on the screen.

The pen is able to detect clicks, screen contact, and tilt.

The microcontroller is able to take input from the wireless pen and the wireless sensors.

Each battery-powered unit is successfully powered and able to be charged.

## Software

The pen’s input and sensor location data can be converted to mouse clicks and presses.

The pen’s buttons can be mapped to customizable shortcuts/hotkeys.

## Accuracy and Responsiveness

Touch detection and location accuracy is the most crucial criteria for our project’s success. We expect our device to have a 95% touch detection precision. In order to correctly control embedded HID protocols of a device, the data sent and processed by the microcontroller to the device has to have a low error threshold when comparing cursor movements with wearable location.

Touch recognition and responsiveness is the next most important thing. We want our system, by a certain distance threshold, able to detect the device with a relatively low margin of error of about 1% or less. More specifically, this criteria for success is the conclusion to see if our communication network protocol between the sensors, USB HID peripherals, and the microcontroller are able to efficiently transfer data in real-time for the device to interpret these data in a form of cursor location updates, scrolls, clicks, and more.

Latency and lags should have a time interval of less than 60 millisecond. This will be judged based on the DSP pipeline formed in the STM32F4 microcontroller.

## Reliability and Simplicity

We want our device to be easily usable for the users. It should be intuitive and straightforward to start the device and utilize its functionalities.

We want our device to also be durable in the sense of low chances of battery failures, mechanical failures, and systematic degradations.

## Integration and Compatibility

We want our device to be able to be integrated with any type of screens of different architectural measurements and operating systems.

Project Videos