Weather Assistant

Portable Pocket Weather Station

Aarav Garg

Issue 46, May 2021

Instead of reaching for a breadboard to build a mini weather station project, 15-year-old maker Aarav chose to make a portable solution that could easily be carried in a pocket.

Once a maker gets an LED to blink for their first “hello world” Arduino project, it is common for the second project to use some form of input sensor. For example, it could be using an ultrasonic module to measure distance or a DHT11 sensor to measure temperature and humidity in the room.

To learn how to get the sensor and Arduino board to work together, many of us would look to Google to find tutorials and code to save us time. In the case of getting a DHT11 sensor to work with an Arduino, there are over 1.5 million search results on how to do this, with many of them involving a breadboard. Enter Aarav and his alternate design to avoid being just one of the many other common tutorials online. Instead, Aarav designed and built a battery-powered mini weather station that was self-contained and able to be carried to different locations by easily fitting in his pocket. No breadboard needed.

Talking about robotics at a high school
Times of India Newspaper

Aarav submitted his project via our website to tell us about it so we caught up with him to find out more.

Thank you for sending us details on your project, Aarav. Before we learn more about your project, please tell our readers a little about yourself.

I am a 15-year-old boy living in India. I have been building robots and tinkering with technology since the age of 10, including developing many apps.

My journey through robotics has even been covered in multiple newspapers, and I have also taught robotics in two high schools in India and given a talk in a university.

Wow. We are very impressed that you have been able to stand up in front of a class to talk about your projects at such a young age. Well done. How did that come about?

In the first school where I taught robotics, I was invited by the principal of the school. The principal of that school is a neighbour of mine and she runs a school for underprivileged children. When she got to know about me, she reached out to me asking whether I could teach robotics to high school students and I found it to be a great idea and went along with it. For the next school, the president of the school was a doctor and he was my family doctor. So when he got to know about what I do, he too proposed me for the same thing and I surely went along with the idea. I taught robotics in both of these schools as an act of social service.

Brilliant. What originally got you interested in electronics as a hobby?

I have had a passion for technology since a very young age. I used to tear apart old electronic items in the house which I found to be really interesting. I also tried to fix many of them. I would also hack gadgets to improve them like converting a wired headphone into a wireless one. These fun projects fueled my interest in electronics and technology in general.

I was only taught the basics of Qbasic in sixth grade when I was 9-10 years old and after that, I have completely self-learnt languages like C, C++, Python, Java, HTML, CSS etc. and also completely self-learnt robotics and electronics!

With regards to writing apps, I used to make these when I was 12 years old. I first built apps like roll the dice, fortune teller etc. Then I made more advanced apps that incorporated a database and other complex features. I built apps like chat apps, social media concept apps etc. All of the app development that I have done is Android app development and I used the standard Google Android Studio to develop these apps.

If you’re like us, being self taught is a great way to learn. What motivated you to build your pocket weather station?

This is my latest project. I wanted to make a tutorial on the DHT11 temperature sensor and wanted to teach people how we can easily utilise its potential with an Arduino board. So, what I did is instead of hooking up some wires into a breadboard and making a boring tutorial, I made a portable Pocket Weather Station and showed the same thing in a much more interesting, effective and professional manner!

You have done well to keep it compact and to finish it in a 3D printed case. How does it work and does it use commonly available parts?

It uses a DHT11 temperature sensor and an Arduino-compatible Nano board to find out the weather and features an 0.96” OLED display to show the weather to the user. I used a small 160mAh Lipo battery and TP4056 battery charging module to make it rechargeable. There’s also a small slide switch for power. All the sensors and modules used are completely standard modules and are easily available globally.

Do you find the DHT11 accurate enough for your application, and how is the feels-like reading calculated?

Yes, until now I have found it to be pretty accurate. Though the DHT11 temperature sensor is not an industry standard and can be replaced in the project with more precise sensors, I think for a learning project, it pretty much does its work. I also accidentally switched it on and left it in the refrigerator for around two hours and to my surprise, it was still working and not dead and showed the temperature that my refrigerator was set to.

The "Feels" parameter is just a function that involves both the temperature and humidity and gives a much more relatable temperature by also considering the humidity as an important aspect of weather!

How did you go about designing the project, and what prototyping was involved?

It was a challenging design as I planned to have the device as compact as possible. I first tried to prototype the whole circuit on a breadboard using the test code before putting effort into making it compact. Getting the project functioning initially was more important than fitting all the components compactly. Fortunately, it worked in the first go.

I then had to figure out the best way to fit in all the different components by trying different combinations. Once I worked out the best way, I then designed the 3D model in Tinkercad and got it 3D printed.

That’s a good approach. Did you write the code yourself or remix someone else's?

This is completely an original idea and so I couldn't use any code as a template and completely wrote my own code from scratch. Though it is a matter of fact that the coding was relatively straightforward as the concept and functioning of the device is quite simple.

What challenges did you need to overcome?

As I mentioned earlier, getting all the components to fit within a very small space was a challenging task and consumed a lot of time. There was some really heavy brainstorming. Other than this, I don't think I faced any other major obstacle.

It’s great that you have made your project portable by adding a rechargeable battery. Were there any design considerations needed to do this?

Yes. Firstly you need to make room for the battery and the battery charging module which might not be challenging in bigger projects while in compact ones like my pocket weather station, this proves out to be a real challenge. Also, you need to add a cutout in the enclosure (if present) for the charging port, whichever it is.

Being able to have a purpose-built case obviously helps make it compact. How did you go about designing and sourcing your 3D printed enclosure?

I designed the enclosure in Tinkercad as it is a great software that supports various skill levels. I am obviously not a 3D CAD professional so I found it to be really handy. I got my 3D enclosure printed by IAmRapid (https://iamrapid.com/) which is a 3D printing company in India and they offer some really satisfying amount of quality.

It is very generous of you to share your build and files on Instructables for other makers to use. Would you recommend that our readers do the same if they develop a project of the same calibre? Do you have any advice for doing so?

Thank you. Yes, indeed it is. When people come together and work using collective intelligence is when humanity grows and I totally support Open-Source technologies. I would indeed recommend makers and creators to share their work with the community where their work can reach and be appreciated by similar minds. This would foster a very healthy technological advancement.

If you were to start the project again, would you do anything differently?

I would probably go with the Arduino Pro Mini instead of the Arduino Nano as the former occupies lesser space which is an undue advantage in compact projects like mine.

We’re spoilt for choice now thanks to the many different Arduino boards available now. Where can our readers go if they want to build one of these projects for themselves?

My build with all of the necessary files is on Instructables: https://www.instructables.com/Pocket-Weather-Station-Your-Self-Care-Weather-Assi/

Great, thank you. What are you working on next?

Right now, I am working on a Robotic Arm that can be taught tasks and trained physically using joysticks. It can be taught repetitive tasks using savepoints that save into an array of variables and can then repeat those tasks in a loop. It is going to be a really great project for learning and content creation.

That sounds awesome. We’ll have to get in touch again once you have completed that.