This is the introductory blog to my entry for element14's "Design For A Cause 2021" design challenge. It is my first participation in a Design Challenge, I am very for the opportunity to participate and be able to collaborate with the rest of the participants to share knowledge and problems

It will be a long trip and I hope it will be a lot of fun. Good luck to the rest of the participants! I hope to learn a lot from all of them.

Tracking System for Classroom Ventilation Routines

A STEM project for classrooms

the VenTTracker project - Blog #01 - Introduction and Motivation

Motivation

Ventilation is an important factor in preventing the virus that causes COVID-19 from spreading indoors.

SARS-CoV-2 viral particles spread between people more readily indoors than outdoors.

Ventilation mitigation strategies help to offset the absence of natural wind and reduce the concentration of viral particles in the indoor air.

In all workplaces, schools and tourist accommodation, there must be pure and clean air.

WHO recommends that the ventilation rate be increased by natural or mechanical means, preferably without recycling the air.

The easiest way to increase fresh air is by opening windows and doors.

But the effectiveness of ventilation in many environments is strongly influenced by user behaviour.

Clear messaging is needed about the reasons why good ventilation is important and how to effectively achieve good natural ventilation.

The problems that the project aims to solve:

• How to involve students and teachers in the ventilation routines of their classrooms?
• How to monitor the ventilation routine quality?
  • How many windows have been open?
  • How many doors have been open?
  • How open were the windows and doors?
  • How long have they been open?
  • What time have they opened and closed?
  • How has ventilation influenced the environmental quality of the room?

What am I going to build to solve this problem?

I am going to create a guide to use in STEM classes on how to implement an inexpensive system to measure the efficiency of natural ventilation within classrooms.

The project includes the design of two sensor devices and a monitoring dashboard:

• Design of an IOT device that can be placed on windows, shutters, blinds and doors to be able to keep track of whether they are open or not and in what position they are: Fully open, semi-open, closed ... The system will use several of these devices.
• Design of an IOT device for measuring changes in gas concentrations and other environmental data within the classroom. Multiple meters can be used to collect data at different points in the classroom at the same time.
• Design of a monitoring dashboard to provide information both in real time and in history in order to evaluate the efficiency of natural ventilation and to be able to develop ventilation routines in the classroom that are also energy efficient.

How does it differ from other solutions?

Currently in my region CO2 meters are being used to measure the level of ventilation in the classroom.

They are precise and expensive CO2 meters that neither have an internet connection nor are they running all day.

The ventilation only depends on the good intention of the teacher and there is no way of knowing if he/she is following an efficient routine both from an air renewal point of view and from an energy efficiency point of view.

Furthermore, these devices should not be used to estimate whether the site is virus-free or not. Just to monitor natural ventilation routines. Why not?:

• CO2 does not degrade over time, while viruses in air do, so virus concentrations in air will decrease more rapidly than CO2. The difference depends on various environmental factors, such as UV radiation or temperature.
• Not all areas of the room can be considered well mixed. In both natural and forced ventilation conditions, the central area of a classroom may be well mixed, and corners or other peripheral areas may be less efficiently mixed.

• The emission of CO2 and particles generated by people are not proportional. Speaking loudly, shouting or singing emits more particles, therefore, with the same CO2 concentrations, the risk of contagion will vary.
• Air change rate per hour (ACH) values measured on a day will reflect the conditions of that day, and may vary depending on external meteorological conditions.
• A person's CO2 emission values vary with many factors, such as age, sex, weight, and metabolic activity.

Why is it useful?

• The project aims to involve the people in the classroom in the ventilation of their own space.
• Facilitate understanding of the value and purpose of good natural ventilation.
• Spark interest in iot devices.
• Encourage students to think of a scenario inspired by the real world.
• Take advantage of the student's ability to learn and grow, fostering self-confidence.

How does my solution work? How am I going to use the Arduino Nano 33 IoT board?

The Tracking System for Classroom Ventilation Routines:

• A - Wireless window shutter opening sensor
• B - Wireless door opening sensor
• C - Wireless window opening sensors
• D - Wireless environmental sensor
• E - Monitoring App
• F - IoT Cloud

Wireless door and window opening sensor

• IOT devices that can be placed on windows, shutters, blinds and doors to be able to keep track of whether they are open or not and in what position they are: Fully open, semi-open, closed ... The system will use several of these devices.
• The device uses an Arduino Nano 33 IoT. With the LSM6DS3 IMU sensor it estimates the degree of opening of the window by means of the readings of the digital accelerometer and the 3D digital gyroscope.
• To obtain an origin reference that marks the closed position and the full opened position, it uses reed switches.
• Different solutions will be studied to estimate how opened is the door or window for different types of openings .
• The measurements obtained can be consulted on the device via bluetooth and/or wifi through an embedded web page.
• At regular intervals and / or through triggered events, it sends windows positioning data to the iot cloud.
• The sensor is calibrated by putting it in calibration mode and showing it the closed position and the maximum open position.
• The device can be adapted to multiple types of windows, blinds, shutters and doors.

Wireless environmental sensor

• IOT device for measuring changes in gas concentrations and other environmental data within the classroom. Multiple meters can be used to collect data at different points in the classroom at the same time.
• The device uses an Arduino Nano 33 IoT and the SparkFun CCS811/BME280 Environmental Combo Breakout. It takes care of all atmospheric-quality sensing.
• It uses a CCS811 and a BME280 ICs and provides a variety of environmental data:
  • barometric pressure,
  • humidity,
  • temperature,
  • Total Volatile Organic Compound. TVOCs
  • and equivalent CO2 (or eCO2) levels.
• The measurements obtained can be consulted on the device via bluetooth and/or wifi through an embedded web page.
• At regular intervals and / or through triggered events, it sends windows positioning data to the iot cloud.
• It may have a screen to display data and alerts to enforce a predefined ventilation schedule.

Monitoring dashboard

• The monitoring dashboard allows us to visualize and relate the different variables and study how the different ventilation routines affect the environmental values.
• It also allows you to check if the established ventilation routines are being adequately followed and to schedule alerts if the system needs to warn of deviations.

What are the main features?

Wireless door and window opening sensor

• Can detect if a window/door/blind/shutter is in open or closed state.
• Can be calibrated to sensor the percentage of opening.
• Can sense the orientation and position of the device.
• Sends periodically information about current position and orientation.
• Sends information triggered by the events opened and closed.
• Accepts bluetooth connection to serve information about its state.
• Accepts bluetooth connection to start a web server:
  • that shows graphically the position and orientation of the sensor.
  • allows to configure wifi connection parameters
  • put the sensor in calibration mode
  • set the clock and/or set ntp address to retrieve udp time from internet
• Blinks a led when its in routine mode and the window/door/blind/shutter is not in the desired state

Other applications of the Wireless door and window opening sensor

• Monitoring the refrigerator. Follow-up and monitoring of the opening of a refrigerator door.
• Monitoring a tap. Follow-up and monitoring of the opening of a tap in a sink.
• Remotely monitorable universal multifit kitchen control knob

Wireless environmental sensor

• Sends periodically environmental data: barometric pressure, humidity, temperature, TVOCs and equivalent CO2 (or eCO2) levels.
• Shows environmental data in a little OLED display.
• Can store data in a circular buffer to graph environmental data

• Sends information triggered by the events exceeding the level of some variable.
• Accepts bluetooth connection to serve information about its actual collected data.
• Accepts bluetooth connection to start a web server:
  • that shows graphically the data.
  • allows us to configure wifi connection parameters
  • put the sensor in calibration mode
  • set the clock and/or set ntp address to retrieve udp time from internet

• Blinks a led when alert is sent by the system

Project plan

• Creation and planning of asset repository management and project source codes
• Study the different types of windows and doors. How do they open?
• Design scale models of the windows and doors to check the solutions.
• Construct the scale models.
• Installing the development environment.
• Testing the IMU. Develop an IMU Maze game to get confidence with the board.

• Testing the IMU. Develop an inaccurate meter with the IMU. Is it possible? Can it be used for sliding windows positioning?
• Testing the IMU. Develop a window orientation visualizer. Can it be used to obtain an estimate of the orientation of casement and pivoting windows?
• Testing the IMU. Using TinyML to get an estimated position and/or orientation of the window or door.

• Review and adjust the project plan with the lessons learned.
• Programming a WIFI access point using WiFiNiNa to access by WIFI to the devices parameter configuration page.
• Implementing a service that retrieves and set devices time using NTP
• Creating a embedded web server that allows a visualization of the 3D positioning of the device in real time
• Creating a BLE service to interact with the devices acting as BLE peripherals.
• Connecting the devices to an internal MQTT Broker and streamsheets
• Connecting to Arduino IoT cloud.
• Monitoring ventilation. Tracking and monitoring of window opening.
• Programming and Setting alarms for notices.

• Review power requirements and adjust device design with lessons learned.

• Putting all together. Construct and program the Wireless door and window opening sensor

• Putting all together. Construct and program the Wireless environmental sensor

• Creating documenting materials..
• Bonus: Monitoring the refrigerator. Follow-up and monitoring of the opening of a refrigerator door.
• Bonus: Monitoring a tap. Follow-up and monitoring of the opening of a tap in a sink.

• Bonus: Remotely monitorable universal multifit cooker control knob