Project

# Title Team Members TA Documents Sponsor
43 LeafLink
 Hannah Pushparaj
Hassan Shafi
Praveen Natarajan
LeafLink

Team Members:
Praveen Natarajan (pn17)
Hassan Shafi(hashafi2)
Hannah Pushparaj(hsp5)

PROBLEM

Plants need to be watered constantly for them to stay alive. Depending on certain scenarios, this might not always be possible for people to do (ex: going on vacation, forgetting to water, etc). We want a way to automatically water these indoor plants to make them stay alive.

SOLUTION

A standalone device that automatically senses the moisture level of the soil, and deploys a pump that supplies the plant with just the right amount of water to survive. It uses an onboard soil moisture sensor along with a water pump to supply the plant with water.
The device is designed to be reliable and easy to understand. A simple light shows what it’s doing (normal, watering, or needs attention). It also includes basic safety limits so it can’t keep running forever if something goes wrong, and it can warn the user if the water container is empty or if the device isn’t able to pump water properly. The device can store a basic history of when it watered the plant so the user can see that it’s working.
If we have time, we can add a simple companion app. The app would let the user see the current soil moisture, and it would show a log of recent watering. It would also allow the user to trigger a quick manual watering from their phone if needed (for example, after repotting or during a very hot week). The app is optional as the device should work on its own even without it.

Solution Components

Subsystem 1: Control & Processing

This subsystem serves as the central controller. An ESP32 on our custom-designed PCB reads soil moisture sensor data, executes watering logic, and controls the relay module. The PCB integrates power regulation and some basic status indication.
Components:
- ESP32
- Our Custom PCB
- 3.3 V voltage regulator
- Some LEDs and resistors


Subsystem 2: Soil Moisture Sensing
This subsystem measures soil moisture and provides an analog voltage to the ESP32 ADC pin to drive the water delivery system.
Components:
- Capacitive Soil Moisture Sensor


Subsystem 3: Water Delivery & Relay Control
This subsystem allows the ESP32 microcontroller to turn the water pump on and off by using a relay, acting as a switch between the ESP32 and higher voltage water pump. So essentially the ESP32 GPIO will drive the relay input which will switch pump power on and off.
Components:
- 6-12 V DC Water pump
- 5 V single-channel relay module
- External 5 V power supply
- Tubing and water reservoir


Subsystem 4: User Feedback & Safety
This subsystem provides basic visual feedback based on the current state of the Leaflink system and an emergency stop button
Components:
- Status LEDs (different colors for idle, watering, error).
- Red push button (emergency stop, kills power)


Subsystem 5: Wireless Monitoring
We will also have a remote monitoring feature using the ESP32’s built-in Wi-Fi. In this remote monitoring system we will display the real-time soil moisture readings (maybe even keep track of old readings over a time period), history of recent watering events, and a manual watering trigger button.
Components:
- ESP32 Wi-Fi (already part of chip)
- Simple mobile or web interface

CRITERION FOR SUCCESS

- The ESP32 on our custom PCB correctly reads soil moisture data and determines when watering is required independently (requiring no supervision)
- Ensure proper functionality of the soil moisture sensor by ensuring moisture readings are accurate (for example if we add water the moisture percentage should get higher)
- The ESP32 reliably controls the relay to turn the water pump on and off based on soil moisture thresholds.
- The water pump operates only through the relay and correctly distributes the required amount of water
- The multiple LEDs correctly indicate the current system states, including idle, watering, and error.
- Pressing the emergency stop button immediately cuts power to the water pump and halts any ongoing operation
- Remote monitoring system displays accurate real-time soil moisture data, logs watering events, and allows manual watering control.

Automatic Piano Tuner

Joseph Babbo, Colin Wallace, Riley Woodson

Automatic Piano Tuner

Featured Project

# Automatic Piano Tuner

Team Members:

- Colin Wallace (colinpw2)

- Riley Woodson (rileycw2)

- Joseph Babbo (jbabbo2)

# Problem

Piano tuning is a time-consuming and expensive process. An average piano tuning will cost in the $100 - $200 range and a piano will have to be retuned multiple times to maintain the correct pitch. Due to the strength required to alter the piano pegs it is also something that is difficult for the less physically able to accomplish.

# Solution

We hope to bring piano tuning to the masses by creating an easy to use product which will be able to automatically tune a piano by giving the key as input alongside playing the key to get the pitch differential and automatically turning the piano pegs until they reach the correct note.

# Solution Components

## Subsystem 1 - Motor Assembly

A standard tuning pin requires 8-14 nm of torque to successfully tune. We will thus need to create a motor assembly that is able to produce enough torque to rotate standard tuning pins.

## Subsystem 2 - Frequency Detector/Tuner

The device will use a microphone to gather audio measurements. Then a microprocessor processes the audio data to detect the pitch and determine the difference from the desired frequency. This can then generate instructions for the motor; direction to turn pegs and amount to turn it by.

## Subsystem 3 - User Interface/Display Panel

A small but intuitive display and button configuration can be used for this device. It will be required for the user to set the key being played using buttons on the device and reading the output of the display. As the device will tune by itself after hearing the tone, all that is required to display is the current key and octave. A couple of buttons will suffice to be able to cycle up and down keys and octaves.

## Subsystem 4 - Replaceable Battery/Power Supply

Every commercial product should use standard replaceable batteries, or provide a way for easy charging. As we want to develop a handheld device, so that the device doesn’t have to drag power wires into the piano, we will need a rechargeable battery pack.

# Criterion For Success

The aim of the Automatic Piano Tuner is to allow the user to automatically tune piano strings based on a key input alongside playing a note. We have several goals to help us meet this aim:

- Measure pitch accurately, test against known good pitches

- Motor generates enough torque to turn the pegs on a piano

- Tuner turns correctly depending on pitch

- Easy tuning of a piano by a single untrained person

Project Videos