|33||Air pollution mapping bands
Vatsin Ninad Shah
|# Air pollution mapping bands
- Chirag Nanda (cnanda2)
- Vedant Agrawal (vsa3)
- Vatsin Ninad Shah (vns2)
Many cities are reaching CO2 levels that are becoming toxic. Cities keep track of these pollution levels using the air quality index, which defines pollution levels of the whole city. Nonetheless, the air quality is often worse in specific parts of the city and it changes over the course of the day depending on a variety of factors including traffic, population density, the operation of office buildings, and factories. A more dynamic calculation of air quality can help people decide which routes to take and which places to avoid. Also, there are certain gasses like LPG and methane that in pure form do not have any odor and hence can be hard to detect, making them very dangerous because of how flammable they are. This can especially be a hazard in industries that use these gasses in their pure form where workers need to be notified of leaks.
To improve tracking of pollution levels in smaller localities, we plan on creating a wrist band and an accompanying mobile app that will continuously monitor the air quality around the user. The broader idea is to have thousands of users wear this band to help contribute to a city wide map that everyone can access. Nevertheless, within the time constraints of the course we plan to first create a proof of concept of the band and a simple application that gives alerts to the user about their general vicinity. The app can keep a personal record of air pollutant levels of the places they visited on a map. Additionally, the app can serve as a warning device in indoor spaces.
# Solution Components
## Power Subsystem
We want to use 2 or 3 flat 3v cells to power the bracelet as this is the most compact solution for powering our microcontroller and sensors. We will decide the number of cells needed experimentally. 2 cells might quickly go below 2.5V each under load, in which case they will not be able to supply the required 5V. Since our components need a stable 5V and 3.3V power supply, we will use buck converters to bring this voltage down. A buck converter will lose much less power than a linear regulator, so that is the better solution for a longer battery life. Another advantage of using the buck converters is the stability of the 5V and 3.3V power supplies. Because of the feedback loops, we can ensure that the supply will be stable and no part will be damaged.
## Sensor Subsystem
We wish to sense a number of potentially harmful gasses, which (with sensor part number) are:
- Carbon Dioxide (MQ135)
- Hydrogen Sulphide (SEN - 10916)
- Natural Gas, Propane (SEN - 17049)
- Carbon Monoxide, Natural Gas (SEN - 17050)
- LPG gas - (SEN - 09405)
- Ammonia - (SEN - 17053)
These will all be connected to the microcontroller through analog inputs on the ESP32 microcontroller.
## Microcontroller Subsystem
The microcontroller we wish to use is the ESP32 since it has 18 channels of analog inputs, which is more than enough for our application. It also has Bluetooth and WiFi capabilities which will help us send the data collected to the app. The data collected on the analog pins will be appropriately packaged by the microcontroller and sent to the app over Bluetooth or WiFi.
## app Subsystem
Alongside our band, we plan to create an application that will take the pollution data and update a map with the detected pollutant concentrations. The app will use the phone’s GPS as well as the Google map API to maintain a dynamic record of the air pollution of different areas of the city. The app will also give alerts of which areas should be avoided based on the pollutant data.
# Criterion For Success
- Being able to successfully detect increased concentrations of mentioned harmful gasses and successfully placing them on a dynamic map.
- Notifying the user when they enter an area with increased concentration of mentioned gasses.