Project

# Title Team Members TA Documents Sponsor
85 Modular Desktop Audio Mixer Control
Aarushi Sharma
Dylan Moon
Yulei Shen proposal1.pdf
# Modular Desktop Audio Mixer Control

Team Members:
- Aarushi Sharma (sharma93)
- Dylan Moon (dylanm5)

# Problem

Modern desktop computers have generally revolved around a set paradigm for human-computer interaction: the keyboard and the mouse. However, analog control surfaces can be beneficial in interacting with the many analog-like controls present in a computer. For example, take software volume mixers. They are prevalent in modern computing systems, shipping with the OS on Windows and Linux-based operating systems. However, they are somewhat difficult to access, usually buried behind multiple menus or needing to open a different application to adjust the volumes of individual applications. People like computer power users might have music playing in the background, a call in the foreground, and application audio on top of that, which all needs to be individually adjusted so that important details are heard. Furthermore, for gamers, who may frequently have full-screen applications occupying their screen, minimizing their game to go searching for the volume mixer to turn down the loud voice call that they may have in the background takes up time. The time spent doing so could be the difference between winning and losing their current match.

# Solution

We propose a modular audio control panel that sits on a user's desktop, which can be physically interacted with to smoothly and easily change volumes of individual applications. Since the controls that we want to target are analog (volume controls for individual applications), the control surfaces that the user interacts with will be linear sliders. This allows for quick but also granular control of the volume levels of various applications in the computer.

The system consists of two different types of components. One type of component is a base station that connects to the computer, does processing of inputs (and possibly outputs), and controls and provides power to the other modules. The other type of component are the modules with sliders. We plan to design the system so that the slider modules can be daisy-chained to allow for a user to choose the number of sliders to include in their setup. More details can be found in the Solution Components section.

If time permits, we also want to explore and implement audio output and post-processing through the device. The inclusion of a DSP chip will process the audio output from the system, which we want to use to implement an equalizer mode, which will temporarily switch the application volume controls to equalizer band controls, allowing users to dynamically adjust the sound profile. One of the target userbases for this feature are gamers: adjusting their audio profile on the fly facilitates listening for other players’ footsteps by turning up the frequency range that footsteps reside in, giving them an advantage.

# Solution Components

## Subsystem 1: Base Module

The base module connects to the computer via USB, connects to power (if external power is required e.g. weak power input from USB), and communicates to other modules on the daisy chain to send and receive data.

For this, the base module will have a microcontroller (ESP32-S3) and bus communication transceivers (if using CAN, but we are looking to see if I2C would be sufficient). We would use pogo pins to interface with the neighboring module. In the case we add DSP output, we would additionally require a DSP chip (ADAU1701) to implement EQ and a push button to switch control modes.

## Subsystem 2: Fader Modules

The fader modules physically attach to the base module and each other via magnets. The electrical connection will be done via pogo pins on the sides of each module. Each fader module communicates with the base module using the bus protocol to send fader position data and receive updates about where to set the fader position.

For this, the fader modules will need a microcontroller (e.g. ATtiny1614), however these MCUs can be weaker than the one in the base because they’re reading values from the fader and sending it through the bus protocol (or vice versa). For the motorized fader itself, Behringer sells replacement fader modules that we can repurpose (X32MOTORFADER). We will also need buttons to act as mute and solo, which mute the application and mute all other applications, respectively.

## Subsystem 3: Integration with OS

Windows doesn’t expose the volume mixer controls to hardware, so a program running on the OS is required to receive values from the hardware and change the value.

For this, we are planning to get input via USB and utilize Windows APIs to change the values of the mixers. If we can find a Linux-based device to test on, we would also like to support the PipeWire/PulseAudio volume mixer.

# Criterion For Success

With multiple fader modules connected (e.g. 2), within 0.5 seconds:
Test that bringing the fader all the way down sets volume of respective application to 0.
Test that bringing the fader all the way up sets volume of respective application to 100.
Bringing fader to halfway mark sets volume to around 50 (± 5%).
Mute and solo buttons perform their respective functions (mute respective application, mute other applications) when pressed.
If DSP implemented: switching to equalizer control and modifying equalizer results in an audible frequency-band change within 2.5 seconds.

Waste Bin Monitoring System

Benjamin Gao, Matt Rylander, Allen Steinberg

Featured Project

# Team Members:

- Matthew Rylander (mjr7)

- Allen Steinberg (allends2)

- Benjamin Gao (bgao8)

# Problem

Restaurants produce large volumes of waste every day which can lead to many problems like overflowing waste bins, smelly trash cans, and customers questioning the cleanliness of a restaurant if it is not dealt with properly. Managers of restaurants value cleanliness as one of their top priorities. Not only is the cleanliness of restaurants required by law, but it is also intrinsically linked to their reputation. Customers can easily judge the worth of a restaurant by how clean they keep their surroundings. A repulsive odor from a trash can, pests such as flies, roaches, or rodents building up from a forgotten trash can, or even just the sight of a can overflowing with refuse can easily reduce the customer base of an establishment.

With this issue in mind, there are many restaurant owners and managers that will likely purchase a device that will help them monitor the cleanliness of aspects of their restaurants. With the hassle of getting an employee to leave their station, walk to a trash can out of sight or far away, possibly even through external weather conditions, and then return to their station after washing their hands, having a way to easily monitor the status of trash cans from the kitchen or another location would be convenient and save time for restaurant staff.

Fullness of each trash can isn’t the only motivating factor to change out the trash. Maybe the trash can is mostly empty, but is extremely smelly. People are usually unable to tell if a trash can is smelly just from sight alone, and would need to get close to it, open it up, and expose themselves to possible smells in order to determine if the trash needs to be changed.

# Solution

Our project will have two components: 1. distributed sensor tags on the trash can, and 2. A central hub for collecting data and displaying the state of each trash can.

The sensor tags will be mounted to the top of a waste bin to monitor fullness of the can with an ultrasonic sensor, the odor/toxins in the trash with an air quality/gas sensor, and also the temperature of the trash can as high temperatures can lead to more potent smells. The tags will specifically be mounted on the underside of the trash can lids so the ultrasonic sensor has a direct line of sight to the trash inside and the gas sensor is directly exposed to the fumes generated by the trash, which are expected to migrate upward past the sensor and out the lid of the can.

The central hub will have an LCD display that will show all of the metrics described in the sensor tags and alert workers if one of the waste bins needs attention with a flashing LED. The hub will also need to be connected to the restaurant’s WiFi.

This system will give workers one less thing to worry about in their busy shifts and give managers peace of mind knowing that workers will be warned before a waste bin overflows. It will also improve the customer experience as they will be much less likely to encounter overflowing or smelly trash cans.

# Solution Components

## Sensor Tag Subsystem x2

Each trash can will be fitted with a sensor tag containing an ultrasonic sensor transceiver pair, a hazardous gas sensor, a temperature sensor, an ESP32 module, and additional circuitry necessary for the functionality of these components. The sensors will be powered with 3.3V or 5V DC from a wall adapter. A small hole will need to be drilled into the side of each trash can to accommodate the wall adapter output cord. They may also need to be connected to the restaurant’s WiFi.

- 2x ESP32-S3-WROOM

https://www.digikey.com/en/products/detail/espressif-systems/ESP32-S3-WROOM-1-N16R2/16162644

- 2x Air Quality Sensor (ZMOD4410)

https://www.digikey.com/en/products/detail/renesas-electronics-corporation/ZMOD4410AI1R/8823799

- 2x Temperature/Humidity Sensor(DHT22)

https://www.amazon.com/HiLetgo-Digital-Temperature-Humidity-Replace/dp/B01DA3C452?source=ps-sl-shoppingads-lpcontext&ref_=fplfs&psc=1&smid=A30QSGOJR8LMXA#customerReviews

- 2x Ultrasonic Transmitter/Receiver

https://www.digikey.com/en/products/detail/cui-devices/CUSA-R75-18-2400-TH/13687422

https://www.digikey.com/en/products/detail/cui-devices/CUSA-T75-18-2400-TH/13687404

## Central Hub Subsystem

The entire system will be monitored from a central hub containing an LCD screen, an LED indicator light, and additional I/O modules as necessary. It will be based around an ESP32 module connected to the restaurant’s WiFi or ESPNOW P2P protocol that communicates with the sensor tags. The central hub will receive pings from the sensor tags at regular intervals, and if the central hub determines that one or more of the values (height of trash, air quality index, or temperature) are too high, it will notify the user. This information will be displayed on the hub’s LCD screen and the LED indicator light on the hub will flash to alert the restaurant staff of the situation.

- 1x ESP32-S3-WROOM

https://www.digikey.com/en/products/detail/espressif-systems/ESP32-S3-WROOM-1-N16R2/16162644

- 1x LCD Screen

https://www.amazon.com/Hosyond-Display-Compatible-Mega2560-Development/dp/B0BWJHK4M6/ref=sr_1_4?keywords=3.5%2Binch%2Blcd&qid=1705694403&sr=8-4&th=1

# Criteria For Success

This project will be successful if the following goals are met:

- The sensor tags can detect when a trash can is almost full (i.e. when trash is within a few inches of the lid) and activate the proper protocol in the central hub.

- The sensor tags can detect when an excess of noxious fumes are being produced in a trash can and activate the proper protocol in the central hub.

- The sensor tags can detect when the temperature in a trash can has exceeded a user-defined threshold and activate the proper protocol in the central hub.

- The central hub can receive wireless messages from all sensor tags reliably and correctly identify which trash cans are sending the messages.

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