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.

Project Videos

• ECE 445 Spring 2024 Team 1 - Waste Bin Monitoring System