Hello World! Team VolcaYUH’s resident blogger is here for your weekly entertainment :3. On this page, readers will embark on a journey of trials and tribulations as the team navigates this daunting task of building a collection mechanism and drone. For the first 5 weeks of the special semester, the team was all over the world (France, Indonesia, and Japan) on official scholarly duties. Therefore, our journey only starts on Week 6.
Week 6 – Week 7 (16/6-27/6)
The current design of the end-product is as follows:
- The drone hovers over an area that contains the wanted ash
- Motor 1 retracts a latch connected to the bottom platform, causing the platform to open and the sampling bottle to fall out and embed itself in the ash
- The modified Niskin sampling mechanism is activated, causing the sampling bottle lid to close
- Motor 2 causes a winch to rotate, winding up the string connected to the sampling bottle which results in the bottle to be reeled back up
- The drone returns to the user
Steps 2 and 4 each require a motor to be manually activated remotely. Thus, this section focuses on the development of the circuitry required. For our microcontroller board, we used Arduino Unos.For our transceivers, we used LoRa Module 915MHz SX1262 5km Range.
We can split the circuitry into two sections – the sender remote and the receiver remote.
Sender Remote
Button 1 causes motor 1 to rotate clockwise (CW) while button 2 causes the same motor to rotate anticlockwise (ACW). Button 3 causes motor 2 to rotate CW while button 4 ACW. Button 5 causes both motors to be stationary.
It took a couple of days and a lot of ChatGPT to finalise this circuitry but there are two important things to note:
- Common Ground
The breadboard was used to connect the ground wires of the key module and LoRa module to the Arduino. This is important to ensure that potential differences across the components are consistent to reduce jittering.
- Input Voltage
The LoRa module operates at 3.3V while the key module operates at 5V. It is important to not mix these up as too high an input voltage will damage the LoRa module while too low of an input voltage causes the key module to not work.
Receiver Remote
As we require the motor to continuously rotate, the motor used is the 360° version rather than 180°.
Like the sender remote, there is a common ground across all circuit components, and the appropriate input voltage is used.
Unfortunately, the circuit is not fully functional yet. Even after pressing button 5, the motors continue to rotate slowly. Upon consulting my teacher ChatGPT, it could be due to either two things – bad wire connectivity or faulty Arduino code. This problem will be resolved next week😊.
Drone
In the spirit of fiscal responsibility, we chose to source for a drone that already existed. Luckily, our new saviour Guo Yao told us about this drone that was in the MnT lab.
This drone is promising for a variety of reasons. Firstly, the collection mechanism is expected to be around 500g. Therefore, the drone has to be big enough with strong motors to carry this payload. Secondly, there is already a flight controller (DJI Naza-m V2) installed, meaning less work for us! Hopefully we will be able to figure out how to get the drone to be functional again next week. #fingerscrossed
Collection Mechanism
To read about how the collection mechanism works, please head over to the “Working Principle” tab.
- String has been attached to the plastic bottle and the closing mechanism works when string is stretched manually. Have not hooked it up to the motor yet
- collection mechanism has week points which requires redesigning
Overall, a lot of progress was made over these 2 weeks, but we are still far from completing the project. See you in next week’s entry!
Signing off,
Team VolcaYUH xoxo
Week 8 (30/6-4/7)
Sender/Receiver Remote
SUCCESS! We have successfully set up the LoRa modules to remotely control the movement of the motors. During the debugging process, the most important takeaway we had was that each motor’s “rest” position is unique.
When coding for the motor to be stationary, the conventional code is “motor.write(90)”, where the number in the brackets is on a scale of 0° to 180°. For a continuously rotating motor, the angle controls the direction and speed of rotation. Naturally, one would assume that the midway point of 90° would lead to the motor being stationary. However, the motors continued to slowly rotate when the above code was used. This is because the angles 85° – 95° actually represent the neutral zone where the stationary angle for each motors lie. We therefore had to manually test different angles to find out the stationary angle of the motors that we used, leading to the following code:
The motor successfully reeled a winch that was attached to 120g worth of weights, simulating the bottle and ash that will need to be carried by the drone.
At this point, the motors are almost perfect! The last bit to solve would be that when the motors are supposed to be stationary, the motors periodically jitter and rotate in one direction. We will continue fine-tuning this next week.
Drone
The first step to getting the drone to fly is to be able to control the motors via laptop. When we initially connected a Windows laptop to the drone, problems arose as Windows 11 was incompatible with the drone’s driver. We had 2 options – update the drone’s software (which would take a lot of time) or remove the safeguards Windows 11 has in place and potentially expose our laptops to evil VIRUSES.
Fortunately, there was a third option! As they say, if you can’t beat them, join them. Thus, enter Zhao Hong’s MacBook Air that was released in early 2015, equally as old as the drone.
SUCCESS!
The drone’s driver is compatible with the MacBook and we were able to move the motors. Unfortunately, we need to buy a controller as well as a receiver to fly the drone remotely. Get in girls, we’re going shopping!
Collection Mechanism
Drone Camera
In order to see where we the drone is going and to decide on a suitable ash sampling site, a camera needs to be mounted onto the drone. Thus, we bought a camera, a video transmitter (VTX), and an FPV monitor!
When trying to set up these 3 components, we were able to establish a connection between the transmitter and monitor. However, the much of the transmitted image was left to be desired as not only was there a lot of static, but the image was also monochrome and kept jittering.
We feared that this would be the cause of our demise as even our friends could not figure out the cause of this problem. It was at this point where we decided we needed the help of a PROFESSIONAL.
HOT NEWS!!!
It is a solemn week. Someone threw our 3D print into the trash. A little birdie told me that someone else’s print got trashed as well. Detective Rauf is on the case, and he will report back. There is a current list of suspects but this story is still developing (hence its appearance on the development page). Please stay tuned… Evil must be SQUASHED. This is a dangerous mission I am embarking on, but it is for JUSTICE. Wish me luck.
Signing off,
Team VolcaYUH xoxo
Week 9 (7/7-11/7)
With the impending doom of deadlines and the final presentation, Team VolcaYUH has stepped up our efforts in putting together this project. This week, while it may not seem like a lot of progress was made, trust when we say we were in the lab racking our brains on how to solve the myriad of problems that emerged.
Shopping
We went on multiple shopping trips to the Central area this week in search of
a remote controller
a camera (for our drone) with a VTX
a flight controller
a spring
that had the appropriate springiness, length, and diameter to fit into our sampling system
a powerbank
that was 5000 mAh and was as light as possible (~100g)
we would need this for the motor (that is attached to our winch)
a box of soil
that was unconsolidated and dense enough for us to create our imitation ash with -> we’re planning on creating a mixture
Flight school
We managed to connect our remote controller to our laptops!
Our fellow drone group recommended that we try a flight simulator game to train our drone operating skills.
Flight school proved to be a challenge for all of us beginners, not to worry though, we will make sure to continue working on it until we get to fly our drone!
Cranky electronics
Figuring out how to incorporate our camera, VTX, and monitor in the circuitry on the drone was also very challenging due to our limited expertise in the area.
Somehow, we couldn’t get our camera to work with our monitor. Our monitor kept going static.
Our receiver continues to refuse to cooperate.
Our VTX also died on us, so we unfortunately had to make another mini shopping trip to replace it.
Assembling our sample system
Assembling the sampling system is unexpectedly a pain in the behind. It was a challenge to superglue the hinge onto the container without getting the hinge mechanism stuck.
On top of that, although we’ve pretty much put the whole prototype together and the mechanism works according to plan, the lid is not closing tight enough onto the mouth of the container. To solve this, we tried playing around with magnets!
As usual, many iterations have been made to ensure that our prototype is in its best condition. Currently, we still have not reached a standard we are satisfied with, so we will continue to work on it in the following week!
Formal Presentation
We had our 2nd round of formal presentation on 10 July! We learnt the importance of structuring our presentation such that the audience can best follow what is going on. Sadly, it seemed that a lot of our course-mates and Professors could not follow our explanations. We’ll make sure to work on this for the upcoming final presentation!
Ash
When researching on the nature of ash, we found that ash is made up of mostly dry silica with variable amounts of rock fragments and crystals. In order to replicate this, we prioritised having variable particle sizes as well as the dryness of our ash replica. Using a mixture of tapioca starch and plain flour as our base, we mixed in dirt, soil, and actual lava rocks, we were able to replicate ash. It was important to ensure that the soil and dirt were sundried before mixing.
— INSERT PHOTO OF ASH HERE–
Signing off,
Team VolcaYUH xoxo
Week 10 (14/7-18/7)
Dear readers,
What a good week it is to be in team VolcaYUH! On Wednesday, we were able to arm AND calibrate our drone (which we named Clammy). This means that Clammy was able to take flight! However, our success was soon impeded by our poor ability to control Clammy and our lack of foresight. Combining the fact that we did not tape down the wires to the drone frame and us losing control of Clammy’s throttle, a propellor struck the wires that connect the controller receiver to Clammy. Luckily, the receiver was not damaged, and we were able to solder new wires to connect the receiver to Clammy again.
On the bright side, we found out that Clammy’s in-built kill switch works as when the connection between the flight controller and receiver was lost, Clammy was able to land by itself in a safe and controlled manner. #LavaOutLoud