## Introduction: Temperature and Humidity Sensor

My name is Tucker Chaisit. I am in my fourth year and currently pursuing a bachelor's degree in Electrical Engineering at the University of Massachusetts Amherst, and I'm a frequent visitor of ECE Makerspace area which also known as M5.

## Step 1: Original Plan

I know that M5 is dealing with a lot of volatile substances and with a massive volume of projects from ECE students. I think there must be some effect on the quality of the air in the area due to the volatile elements which sparked me an idea to build an air quality sensor. The sensor that can collect the data at a real time and report it directly to the user in M5 but to make that sensor, it requires a higher knowledge which I'd like to do in the future. I decided to use a pre-built sensor that collects temperature and humidity instead and focuses more on building the devices that can work with the system in the Makerspace.

## Step 2: What I Learnt Along the Way

To build the sensor that can communicate with the user in the Makerspace and with the help of Professor Charles Malloch. I decided to use ESP8266 Wi-Fi module to help communicate with the IoT platform that has been built already in M5. In order to make all of that, I need to learn about MQTT and brushed up my knowledge about Arduino as well.

## Step 3: Difficulties

There are challenges and difficulties along the way of building the sensor. One of the very first problems that I had was that the ESP8266 has a maximum voltage it could take to work correctly and safely. I need to use a voltage regulator to regulate the voltage to fall in the range of 3 to 3.6V. First, I attempted to use two battery which equivalent to 3V, but the device seems not to have enough power but if you use three battery then the voltage will equivalent to 4.5V which passes the maximum voltage the ESP8266 could take. Near the very end of the semester, I faced a problem of powering on the LCD and have the power supply to work which I later found that the source of the problem is the battery holder which initially has four sockets open meaning that there's open circuit. I solved the problem by connecting the wire between the empty sockets.

## Step 4: How M5 Should Change

I think M5 is an excellent place from anyone who wants to build and work on their project, the only thing I could think of during the time I spent there working on the sensor is to have a wider selection of sensors and parts which M5 already did a great a job having a massive selection! And maybe to make the area more neat, clean and brighter.

## Step 5: What I Accomplished

In the end, I was able to build a sensor and present at the Circuit & Code event held at M5. The sensor is able to collect the data and store them into the Arduino UNO which then sends two signals. The first one that the Arduino sends is to the LCD which displays the states of the sensor and tell the users when the sensor's going to refresh and send another round of data. The second signal transmits to ESP8266 which use to communicate with the IoT system at M5.

## Step 6: How Could Somebody Follow in My Footstep

In my opinion, It's not difficult to build this sensor. You need to learn about MQTT, Arduino UNO, be able to follow and build the circuit from looking at the schematic, and one of the important things that took me some time was being aware and know about the voltage regulator and how much voltages each part needed to perform at their best.

## Step 7: What I Would Do Next

The next things I'd like to do or wish somebody else would do for this sensor is to finish troubleshooting the code to make the sensor able to connect to the IoT correctly and perform its task as a temperature and humidity sensor for M5. After that, I want to work on to build the actual sensor part of the air quality sensor.