Rauf
In my personal life, my friends know me as a professional hater – an immovable object with a refusal to learn. Unfortunately for me, MnT turned out to be an unstoppable force that forcefully thrust me into the complex world of electronic hardware. Through this experience, the following insights have emerged:
- BBB (Bring Back Bimbos!)
Don’t get me wrong, I love being a masochist and struggling in school, with tears threatening to spill at any moment in time. However, I realised that TAs and lab managers are there to help you whenever you’re stuck and require assistance. While we should still venture and try to solve problems by ourselves, there should be no shame in ultimately asking for help. Special shoutout to -redacted- and the owners of Kuriosity for gentle parenting the 3 lost bimbos in Sim Lim Square.
2. Circuitry is circuiTRY
We initially tried to put together the complete circuit for the remotes, including the motors, key modules, and transceivers. When the desired outcome was not observed, we were unable to fix the circuit as we were unsure on the exact portion that was faulty. This led us to test individual circuit components instead, allowing us to conclude that the Arduino code required debugging.
3. ArduiNO? More like Ardui-maybe…
The AD Key Module we used is not that commonly used by others, making it hard to find code from online sources that have already proven to work. We therefore had to be creative and modify the pre-existing code to fit the module that we used.
4. The D in 3D printing stands for sustainable
In 2 weeks, we 3D printed 7 crescent moons meant for the collection mechanism. The reason for the multiple prints were due to wrong dimensions and mistakes made when gluing the prints together. These mistakes were avoidable and are at the cost of our environment, as thermoplastics require energy to be recycled, wasting even more resources.
5. Busy day, silent night
Throughout this process, we took up a new hobby – singing! Stay tuned for our final presentation to hear what we have been working on 😉
Yuan Fang
1. Drone Configuration
When we first received the drone, we initially thought everything had been set up and that all we needed to do was learn to fly it. However, we were wrong.
The first hurdle was calibrating the DJI Naza M V2 flight controller. This controller, released in 2013, is quite outdated. We had to install both the DJI Assistant Software and DJI Driver to connect it to our laptop. The DJI Driver acts as a “translator” between the computer and the flight controller.
While there were no issues with downloading or running the DJI Assistant Software, the DJI Driver installer would not launch properly. Even after using Command Prompt to run it, the driver could not be read. The drone could recognise the laptop, but the laptop could not recognise the drone.
After several hours of replugging the flight controller and adjusting laptop settings, we concluded that the only way to connect Windows 11 to the controller was by temporarily turning off secure boot. Since this was too risky, we decided to try a different approach.
The next day, we tried connecting the controller using Zhao Hong’s 2015 MacBook — and it worked! We didn’t have to buy and configure a new flight controller after all.
Another obstacle: the drone had no receiver or camera attached. Initially, we thought we only needed to buy two things, but it turned out to be more complicated.
- For the camera, we also needed a video transmitter, FPV monitor, and antennas, and had to do some soldering for the transmitter.
- For the controller, we needed batteries and a receiver, and also had to do soldering for the receiver.
Once all the soldering was done, we struggled to connect and calibrate the controller.
- First, binding the receiver to the controller was difficult. It required plugging and unplugging the receiver from the flight controller. The wire was hard to unplug, so we had to use tweezers and repeat the process quickly three times. After about 3 hours of trying, we realised the wire was inserted in the wrong orientation.
- After binding the receiver, the controls still weren’t being reflected in the flight controller. After reading many manuals, watching videos, and consulting ChatGPT, I finally understood the problem. Our receiver is a Radiomaster DBR4, which uses ExpressLRS (ELRS). ELRS communicates using the Crossfire (CRSF) protocol. Inside EdgeTX settings, I had to enable the Internal RF and set the protocol to CRSF. This told the radio to send control data using CRSF, which worked — the controls were finally reflected in the DJI Assistant Software.
- We then faced issues with calibrating the flight modes — GPS, Atti, and Failsafe. Initially, toggling the 3-way switch only resulted in “Failsafe → Failsafe → Failsafe.” After further research, we learned that the Naza-M V2 reads flight mode commands through Pulse Width Modulation (PWM) signals on servo channels (e.g. CH5, CH6). Each switch position corresponds to a specific PWM pulse width (in microseconds, µs). The PWM signal output from the receiver was out of DJI’s working range, so we calibrated it by increasing the minimum PWM, decreasing the maximum PWM, and adjusting the offset (a constant value that it added/subtracted from all PWM output) . This allowed the 3-way switch to finally trigger all three flight modes.
- One more challenge: during a test flight, the receiver was ripped off the drone and got damaged. We re-soldered it, but the drone kept losing signal. We initially thought it was a battery issue, but upon closer inspection, we confirmed it was the receiver. Aik Thong helped us re-solder the receiver again, and after reconnecting, the drone worked properly.
Although the drone was not the main focus of our project, it took a lot of time and effort to set it up. We spent about 2–3 weeks troubleshooting and learning. Despite the frustration, it was a very rewarding experience.
2. Overall Assembly
The assembly of our sampling system, while not technical in terms of software, still took considerable time and effort. We brainstormed many designs over 4–5 days, constantly thinking about the best system.
We were inspired by the Niskin sampler used during our ES1006 Bali fieldwork to collect deep water samples. It uses a mechanical (non-electric) lid-closing mechanism, which was ideal for adapting to our drone.
The Niskin system is complex, with multiple parts working together: Rubber string (inside the bottle), nylon string (outside), a lowering string, hook for the nylon string, spring, weights
We had to make the Niskin sampler smaller by more than 10× to fit our drone.
Many prototypes were developed as we iteratively improved the bottle mechanism. It took about a month and many 3D prints to get a working prototype.
- Challenge 1: Too much friction between the hook and string prevented the lid from closing. Guo Yao helped us solve this by removing the hook and lodging the string between two platforms instead. This setup provided enough friction during descent and allowed the string to release when the messenger weight dropped.
- Challenge 2: Determining the correct weight and release height. Initially, we dropped a 40g weight from 10m, which broke the bottle. After calculations, we found that only 26mg dropped from 2m was needed to compress the spring slightly and release the string. However, we had to account for air resistance, friction (between string and weight, and between string and platform), energy loss, and imperfect alignment of the weight. We ultimately decided that 40g dropped from 2m worked best and was consistent.
3. Presentation
There were many aspects to our projects that we felt were important to share with our audience:
Why volcanic ash?: Volcanic ash are pyroclasts produced during volcanic eruptions and measuring less than 2 mm in diameter. They are used in determining magma composition (E.g. crystal percentage, density, grain size, mafic or felsic), studying respiratory and ingestion hazards from an eruption, and assessing environmental impacts of eruption (E.g. on agriculture, water sources, buildings, living things).
Setting up a drone: While the drone may seem like it was just ‘given’ to us in working condition, as mentioned above, a lot of time and effort was put into setting it up and getting it ready for flying. We wanted our audience to know the complexities of a drone and how many different components work together for a drone to fly.
Explaining the very complex Niskin sampling system: The Niskin bottle is not widely known outside the field of environmental science, so explaining it to our audience in a simple and digestible way was very important.
- Our sampling bottle was very small, and showing how the prototype works to others was a struggle. We decided to use Autodesk Fusion to create a 3D design and video to show how it works on a bigger screen (credits to Zhao Hong)
- A Niskin bottle cannot be used in atmospheric pressure, it is built for use in deep waters and can crack when used in air. This meant that we could not use the real (and bigger) Niskin bottle during presentations to show how it works.
Overall, MnT was a very meaningful learning experience, whether it was about the technicalities of a drone or trying to be a group leader and ensuring everything went as planned. I am very grateful for my group members for putting their best effort into their roles and responsibilities.
Caitlin
Learnt about independence
If there’s one thing I have learnt from the MnT module, it would be the value of independence. We all had the liberty and autonomy of starting projects on almost anything under the sun. As such I felt that we had a responsibility to follow through with whatever we set out to do and commit to our project. My group and I had to be self-sufficient as we worked on our project. Zhao Hong and I had to learn how to use the Autodesk Fusion software as well as the lab’s 3D printing set-up so that we could bring our 3D print ideas into reality. It was initially frustrating getting used to the software as my progress felt slow and inefficient. Throughout the course of the project, as I spent more time on the software and made an effort to explore the various features available, as well as experiment. I eventually improved my 3D designing skills and was able to flesh out designs much faster than I did before.
I am also proud to have witnessed my friends overcome their own learning curves to pick up skills that were essential to making our project a success. Rauf’s tireless efforts to learn how to write Arduino code and set up circuits so that our motor and remotes could work was impressive and admirable. Watching Yuan Fang relentlessly go through countless rounds of trial and error to get our collection mechanism to work as it should was greatly inspiring. As for Zhao Hong, the hard work that she put into doing research on our drone and setting up was heartening considering that it was out of her expertise.
Importance of trial and error
Furthermore, I was able to better appreciate the process of trial and error. All of us are more familiar with it now that we have gone through this entire module, which you will be able to see in the Development page. For instance, when it came to 3D printing the parts for our sampling system, we had to go through a repetitive process of printing a part, testing it out, re-evaluating, then redesigning and printing it again. This period of time felt mundane, but at the same time greatly satisfying because with each part we 3D printed, the closer we would get to reaching our final, best prototype (which we eventually did!). It was relieving and heartening when we finally got to testing the various components of our project and could actually see our ideas being turned into reality. Some moments to note would be testing our sender and receiver remotes that control the motor as well as the lid closing mechanism of our sampling system, and flying our drone without restraints for the first time.
Overall, MnT has been an immensely fruitful experience for me.
Zhao Hong
- Communication and Teamwork
Being a team of four meant that while we held certain roles on paper, our roles overlapped and intersected in practice. We survived and thrived only because we actively helped each other out in all components of the project and those who had spent more time on a certain component did not hesitate to catch up the other members on the project. Our small group size meant that we did not really have the liberty to only “specialize” on one part of the project, rather, everyone was equally involved in all parts. To ensure that everyone had a good grasp of the entire project, communication was key. Beside that, it was important that in the event that we were absent for a certain period of time, we had to take initiative to keep up to date with the progress of the team. Through the informal and formal presentations, I learnt how to communicate succinctly and effectively, with sketches and 3D models. Hanyang commented after our formal presentation that quantifying our claims would make clear the improvement that our project makes to current methods of volcanic ash collection. I learnt a lot about my friends’ working styles and learnt how to communicate what I wanted in a respectful and effective manner.
2. Practical Skills
Having never touched a solder or a circuitry board before in my life, working on our project was definitely a steep learning curve. Learning how to use Fusion360 in an optimal and efficient manner was frustrating but satisfying, ultimately being able to see my designs come to life. They are ultimately a bunch of shapes put together but nonetheless, beautiful! Beauty is in the eye of the beholder after all. Using Fusion360 to make 3D animations was another hurdle.
The other major part of our project was the drone. It was really challenging to understand how to make it fly and then, how to fly later on. Our drone is made up of many components: flight controller (FC), electronic speed controllers (ESCs), motors, battery, receiver etc. I had to learn how to carefully sift through the information I found online as I was still unfamiliar with drone jargon and was desperately learning on the go. Oscar Liang’s website was a big help though. In order to make it fly, firstly, the radio transmitter had to be connected (“bound”) to the receiver on the drone. In short, our issue was that the receiver wires were connected incorrectly to the FC so the LED receiver was not even flashing. This took us several hours to figure out. After solving that, we still had to power cycle the drone to bind the receiver, which eventually was a success. This allowed us movement on the radio transmitter to be reflected on the NAZA M app. Secondly, we had to arm the drone which after several hours of research again, required GPS calibration. Yuan Fang elaborates on this challenge in-depth in her reflection but in short, there was no comprehensive manual to put all these together. We were using different brands and models for each component and we had to track down each of their individual manuals.
Regardless, I enjoyed the learning process, no matter how frustrating. I appreciated the help extended to us by Yaoxiang, Fuden, Guo Yao and Aik Thong and how patient they were throughout the process. The learning curve was really steep but I got so much more out of this MnT journey.