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Team Status Report for 10/19

In the week prior to fall break and throughout the week of fall break our team continued to make good progress on our project. Having received the majority of the hardware components we ordered, we were able to start the preliminary work for flashing the esp32’s with the Arduino code necessary to relay the accelerometer data to our laptop. Additionally, we made progress in our understanding and implementation of the audio playback module, and implemented the final feature needed for the webapp: a trigger to start the ring detection protocol locally.

Currently, the issues that pose the greatest risk to our teams success are as follows:
1.) Difficulty in implementing the BLE data transmission from the drumsticks to the laptop. We know that writing robust code, flashing it onto the esp32’s, and processing the data in real time could pose numerous issues to us. First, implementing the code and flashing the esp32 is a non-trivial task. Elliot has some experience in the area, but having seen other groups attempting to do similar things and struggle, we know this to be a difficult task. Second, since the transmission delay may vary from packet to packet, issues could easily arise given a situation where a packet takes far longer to transmit than others. Currently our mitigation strategy involves determining an average latency through testing many times over various transmission distances. Once we have this average it should encompass the vast majority of expected delay times. If a transmission falls outside of this range, we plan on simply discarding the late packets and continuing as usual.

2.) Drumstick tip detection issues. While it seems that using the cv2 contours function alongside a color mask will suffice to identify the location of the tips of the drumsticks, their is a fair amount of variability in detection accuracy given available lighting. While we currently think applying a strong color mask will be enough to compensate for lighting variability, in the case that it isn’t we plan on adding a lighting fixture mounted alongside the camera on the camera stand to provide consistent lighting in every scenario.

3.) Audio playback latency. As mentioned in the previous report, audio playback can surprisingly introduce significant amounts of latency to the system (easily 50ms) when using standard libraries such as pyGame. We are now using the soundDevice library instead which seems to have brought latency down a bit. However the issue is not as simple as reducing sample buffer size as we have noticed through experimentation that certain sounds, even if the duration of the sounds don’t vary, require higher buffer sizes than others. This is a result of both the sampling frequency used and the overall length of the data in the sound file. Using soundDevice and by interacting directly with the windows WASAPI (windows sound driver) we believe c=we can cut latency down significantly, but if we can’t we plan on using an external Midi controller which facilitates almost instantaneous sound I/O. These controllers are designed for these exact types of applications and help circumnavigate the audio playback pipeline inherent in computers.

The design of our project has not changed aside from the fact that we are now trying to use (and testing with) the soundDevice library as opposed to pyAudio. However, if soundDevice proves insufficient, we will revert and try employing pyAudio with ASIO. We are still on track with our schedule.

Below are the answers to the thought questions for this week.
A was written by Ben Solo, B was written by Elliot Clark, and C was written by Belle Connaught

A.) One of DrumLite’s main appeals is that it is a cost effective alternative to standard electronic drum sets. As was mentioned in the introduction of our design report, a low end drum set can easily cost between $300 and $700 while a better one can go up to $2000. Globally, the cost of drum sets, whether acoustic or electronic, hinder people from partaking in playing the drums. DrumLite’s low cost (~$150) enables many more people to be able to play the drums without having to worry that the cost isn’t justifiable for an entertainment product.
Furthermore, DrumLite makes sharing drum sets infinitely easier. Previously sharing a drum set between countries was virtually impossible as you’d have to ship it back and fourth or buy identical drum sets in order to have the same experience. But with DrumLite, since you can upload any .wav files to the webapp and use these as your sounds, sharing a drum set is trivial. You can just send an email with four .wav attachments and the recipient can reconstruct the exact same drum set you had in minutes. DrumLite not only brings the cost of entry down, but encourages collaboration and the sharing of music on both a local and global scale.

B.) The design of this project integrates several cultural factors that enhance its accessibility, relevance, and impact across user groups. Music is a universal form of expression found in many cultures, making this project inherently inclusive by providing a platform for users to experience drumming without the need for expensive equipment. Given its highly configurable nature, the system can be programmed to replicate sounds from a variety of drums spanning various cultures, therefore enabling cross-cultural appreciation and learning. This project also holds educational potential, particularly in schools or music programs, where it could be used to teach students about different drumming traditions, encouraging cultural awareness and social interaction through drumming practices seen in other cultures. These considerations collectively make the drumlite set not only a technical convenience but also a culturally aware and inclusive platform.

C.) DrumLite addresses a need for sustainable, space-efficient, and low-impact musical instruments by leveraging technology to minimize material use and environmental footprint. Traditional drum sets require numerous physical components such as drum shells, cymbals, and hardware, which involve the extraction of natural resources, energy-intensive manufacturing processes, and significant shipping costs due to their size and weight. By contrast, our project replaces bulky equipment with lightweight, compact components—two drumsticks with embedded sensors, a laptop, and four small rubber pads—significantly reducing the raw materials required for production. This not only saves on manufacturing resources but also reduces transportation energy and packaging waste, making DrumLite more environmentally-friendly.
In terms of power consumption, the system is designed to operate efficiently with the use of low-power ESP32 microcontrollers and small sensors like the MPU-6050 accelerometers. These components require minimal energy compared to traditional electric drum sets or amplification equipment, reducing the device’s carbon footprint over its lifetime.
DrumLite contributes to a sustainable musical experience by reducing waste and energy consumption, all while maintaining the functionality and satisfaction of playing a traditional drum set in a portable, tech-enhanced format.

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Ben Solo’s Status Report for 10/5

In the days after the deign presentation I fell slightly behind schedule on implementing the infrastructure of our audio playback module as I outlined as a task for myself last week. The primary reason for this was due to an unexpected amount of work in my three other technical classes, all of which have exams coming up this week. I was unable to actually create a useful interface to trigger a sequence of sounds and delays, but did spend a significant amount of time researching what libraries to use as well as investigating latency related to audio playback. I now know how to approach our playback module and can anticipate what problems we will likely encounter. We previously planned on using PyGame as the main way to initiate, control, and sequence audio playback. However, my investigation showed that latency with PyGame can easily reach 20ms and even up to 30ms for a given sound. Since we want our overall system latency to remain below 100ms (ideally closer to 60ms), this will not do. This was an oversight as we assumed audio playback to be one of the more trivial aspects of the project. After further research it seems that PyAudio would be a far superior library to utilize for audio playback as it offers a far greater level of control when it comes to specifying sampling rate and buffer size (in samples). The issue with pyGame was that it used a buffer size of 4096 sample. Since playback latency is highly dependent upon buffer latency, a large buffer size like this introduces  latency we can’t handle. Buffer latency is calculated as follows:

Buffer Latency (seconds) = (Buffer size {samples}) / (sampling rate {samples per second})

So at the standard audio sampling rate of 44.1kHz, this results in 92.87ms of just buffer latency. This would basically encompass all the latency we can afford. However, by using a lower buffer size of 128 samples and the same sampling rate (since changing the sampling rate could introduce latency in the form of sample rate conversion {SRC} latency) we could achieve just 2.9ms of buffer latency. Reducing the buffer means that fewer audio frames are stored prior to playback. While in standard audio playback scenarios this could introduce gaps in sound when processing a set of frames takes longer than the rest, in our case, since sound files for drums are inherently very short, a small buffer size shouldn’t have much of a negative effect. The other major source of audio playback latency is the OS and driver latency. These will be harder to mitigate but through the use a low latency driver like ASIO (for windows) we may be able to bring this down too. It would allow us to bypass the default windows audio stack and interact directly with the sound card. All in all, it still seems achievable to maintain sub 10ms audio playback latency, but will require more work than anticipated.

Outside of my research into audio playback, I worked on figuring out how we would apply the 30mm margin around each of the detected rings. To do so, we plan on storing each of the actual radii of the drum rings in mm; then when we run our circle detection algorithm (either cv2 ‘s HoughCircles or Contours) which return pixel diameters and compute a scaling ratio = (r_px)/(r_mm). We can then apply the 30mm margin by adding it to the mm unit radius of a given drum and multiplying the result by the scaling factor to get its pixel value.
i.e. adjusted radius (px) = (r_mm + 30mm) * (scaling factor)

This allows us to dynamically add a pixel equivalent of 30mm to each drum’s radius regardless of the camera’s height and perceived ring diameters.

I also spent some time figuring out what our max drum set area would be given camera height and lens angle, and came up with a graphic to demonstrate this. Using a 90 degree lens, we have a maximum achievable layout of 36,864 cm^2, which is 35% greater than that of a standard drum set. Since our project is met to make drumming portable and versatile, it is important that it can both be shrunk down to a very small footprint and expanded to at least the size of a real drum set.

(link here)

In the coming week I plan on looking further into actually implementing our audio playback module using PyAudio. As aforementioned, this will be significantly more involved than previously thought. Ideally, by the end of the week I’ll have developed a module capable of audio playback with under 10ms of latency, which will involve installing and figuring out exactly how to use both PyAudio and most likely ASIO to moderate driver latency. As I also mentioned at the start of my report, this coming week is very packed for me and I will need to dedicate a lot of time to preparing for my three exams. However, if I am already planning on spending a considerable amount of time over Fall break in order to both catch up my schedule and make some headway both on the audio playback front and integrating it with out existing object detection code such that when a red dot is detected in a certain ring, the corresponding sound plays.

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Ben Solo’s Status Report for 9/28

This week I focused predominantly on setting up a working (locally hosted) webapp with integrated backend and database, in addition to a local server that is capable of receiving and storing drum set configurations. I will explain the functionality of both below.

The webapp (image below):
The webapp allows the user to completely customize their drum set. First they can choose to upload any sound files they want (.mp3, .mp4, or .wav). These sound files are stored both in the MySQL database and in a server localized directory. The database holds metadata about the sound files such as what user they correspond to, the file name, the name given to the file by the user, and the static url used to fetch the actual data of the sound file from the upload directory. The user can then construct a custom drum set by either searching for sound files they’ve uploaded and dragging them to the drum ring they wish to play that sound, or by searching for a saved drum set. Once they have a drum set they like, they can save the drum set so that they can quickly switch to sets they previously built and liked, or click the “Use this drum set” button, which triggers the process of sending the current drum set configuration to the locally running user server. The webapp allows for quick searching of sounds and saved drum sets and auto populates the drum set display when the user  chooses a specific saved drum set . The app runs on localhost:5000 currently but will eventually be deployed and hosted remotely.

The local server:
Though currently very basic, the local sever is configured to run on the users port 8000. This is important as it defines where the webapp should send the drum set configurations to. The endpoint here is CORs enabled to ensure that the data can be sent across servers safely. Once a drum set configuration is received, the endpoint saves each sound in the configuration with a new file name of the form “drum_x.{file extension}”, where x represents the index of the drum that the sound corresponds to, and {file extension} is either .mp3, .mp4, or .wav. These files are then downloaded to a local directory called sounds, which is created if the user hasn’t already done so. This allows for very simple playback using a library like pyGame.

In addition to these two components, I worked on the design presentation slides and helped develop some new use case requirements which we based our design requirements off of. Namely, I came up with the requirement for the machined drumsticks to be below 200g, because as a drummer myself, increasing the weight much above the standard weight of a drumstick (~113g) would make playing DrumLite feel awkward and heavy.  Furthermore, we developed the use case requirement of ensuring the 95% of the time that a drum ring is hit, the correct sound plays. This has to do with being confident that we detected the correct drum from the video footage, which can be difficult. To do this, we came up with the design requirement of using an exponential weighting over all the predicted outcomes for the drumsticks location. By applying a higher weight to the more recent frames of video, we think we can come up with a higher level of confidence on what drum was actually hit, and subsequently play the correct sound. This is a standard practice for many such problems where multiple frames need to be accurately analyzed in a short amount of time.

Lastly, I worked on a new diagram (also shown below) for how the basic workflow would look. It aids more as a graphic for the design presentation, but does convey a good amount of information about how the flow of data looks while using drumLite. My contributions of the project are coming along well and are on schedule. The plan was to get the webapp and local server working quickly so that we’d have a code base we can integrate with once we get our parts delivered and can actually start building out the code necessary to do image and accelerometer data processing.

In the next week my main focus will be creating a way to trigger a sequence of locally stored sounds within the local code base. I want to build a preliminary interface where a user inputs a sequence of drum id’s and delays and the corresponding sounds are sequentially played. This interface will be useful, as once the accelerometer data processing and computer vision modules are in a working state, we’d extract drum id’s from the video feed and pass these into the sound playing interface in the same way as is done in the above described simulation. The times at which to play the sounds (represented by delays in the simulation) would come from the accelerometer readings. Additionally, while it may be a reach task, I’d like to come up with a way to take the object detection script Belle wrote and use that to trigger the sound playing module I mentioned before.

(link to image here)


(link to flow chart here)

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Team Status Report for 9/28

This week our team focused heavily on preparing for the design presentation. This meant not only continuing to build up our ideas and concepts for DrumLite, but in doing so, actually starting to develop some base code to be used for both initial experimentation and proof of concept, but also for testing purposes down the line. We initially struggled with coming up with design requirements base on our use case requirements. We couldn’t really understand the difference between the two initially, but came to the conclusion that while use case requirements were somewhat black boxed and focused more on how the product needs to behave/function, design requirements should focus on the requirements that need to be met implementation-wise in order to achieve the use case requirements.

We then developed our design requirements and directly related them to our use case requirements. In doing so, we also added 3 new use case requirements, which are indicated using * below. These were as follows :
1.) (use case) Drum ring detection accuracy within ≤30 mm of actual placement.

(design)Dynamically scale the detected pixel radii to match the actual ring diameters + 30mm of margin

2.) (use case) Audio response within ≤100ms of drumstick impact.

(design)BLE <30 ms, accelerometer @1000Hz, CV operating under 60ms (~15fps)

3.) (use case) Minimum layout area of 1295 cm2 (37cm x 35cm).

(design) For any given frame, the OpenCV algorithm will provide a proximity check to ensure the correct choice across a set of adjacent rings

4.) (use case*) Play the sound of the correct drum >= 95% of the time.

(design) Average stick location across all processed frames.
Exponential weighting 𝞪 = 0.8 on processed frames.

5.) (use case*) BLE transmission reliability within 10ft from laptop

(design) <=2% BLE packet loss within 10 ft radius of the laptop.

6.) (use case*) Machined drum sticks under 200g in weight.

(design) Esp32 : 31g, MPU-6050: 2g, Drumstick: 113.4g –> Ensure connective components are below 53.6g.

Individually we each focused on our own subdivisions within the project in order to either establish some ground work or better understand the technologies were working with.

Ben: Worked on creating a functioning, locally hosted webapp integrated with UI to allow for drum set configuration/customization, sound file and drum set configuration storage (MySQL), and an endpoint to interact with a users locally running server. He also worked on a functioning local server (also using flask) to receive and locally store sound files for quick playback. Both parts are fully operational and successfully communicate with one another. The next tasks will be to integrate the stored sound files with other code for image and accelerometer processing that also runs locally. Finally, the webapp will need to be deployed and hosted. Risks for this component of the project are centered around how deploying the webapp will affect the ability for the webapp server to communicate with the local one, as currently the both run on local host.

Belle: Focused on developing a testing setup for our object detection system. In order to determine the average amount of time required for OpenCV object detection to identify the location of a drumstick tip, Belle created a MATLAB script in which she drew 4 rings of varying size and moved a red dot (simulating the tip of the drum stick) around the 4 rings. We will use a screen capture of this animation in order to determine a.) the amount of time it takes to process a frame, and b.) subsequently the number of frames we can afford to pass to the object detection module after detecting a hit. Currently, she has a python script using OpenCV that is successfully able to identify the location of the dot as it moves around within the 4 rings. The next step here is to come up timing metrics for object detection per frame.

Elliot: Elliot spent much of his time in preparation for the design presentation, fleshing out our ideas fully, and figuring out how best to explain them. In addition, he worked out how we will communicate with the MCU and accelerometer contained by the drumsticks via python. He additionally looked into BlueToothSerial for interfacing with the ESP32, and confirmed that we can use BLE for sending the accelerometer data, and usb for flashing the microcontroller. Finally, he identified a BLE simulator which we plan on using both for testing purpose and for preliminary research. This simulator accurately simulates how the ESP32 will work, including latency, packet loss, and so fourth.

In regards to the questions pertaining to the safety, social, and economic factors of our project, these were our responses (A was written by: Belle , B was written by: Elliot, C was written by: Ben)

Part A: Our project takes both public health and safety into consideration, particularly with regard to the cost and hazards of traditional drum sets. By focusing on mobility, the design enables users to play anywhere as long as they have a surface for the drum rings – effectively removing the space limitations often encountered with standard drum sets, and offering a more affordable alternative that lowers financial barriers to musical engagement. This flexibility empowers individuals to engage with their music in diverse environments, fostering a sense of freedom and creativity without having to worry about transporting heavy equipment or space constraints. Additionally, the lightweight, compact nature of the rings ensures that users can play without concerns of drums falling, causing injury, or damaging surrounding objects. This design significantly enhances user safety and well-being, and promotes an experience where physical well-being and ease of use are key.

Part B: Our CV-based drum set makes music creation more accessible and inclusive. This project caters to individuals who may not have access to physical drum sets due to space constraints, enabling them to engage in music activities without needing traditional instruments. The solution promotes the importance of music as a means of social connection, self-expression, and well-being. The project also helps foster inclusivity by being adaptable to different sound sensitivities, as you can adjust the sound played from each drum. By reducing the barrier to entry for using drum equipment, we aim to introduce music creation to new audiences.

Part C: As was stated in our use case, drum sets, whether electronic or acoustic, are very expensive (easily upwards of $400). This limits the number of people who are able to engaging in playing the drums greatly simply because there is a high cost barrier. We have calculated the net cost of our product which sits right around $150, nearly a quarter of the price of a what an already cheap drum set would cost. The reason for our low cost is that the components of a physical drum set are much more expensive. Between a large metal frame, actual drums/drum pads, custom speakers, and brain to control volume and customization, the cost of an electronic drum set sky rockets. Our project leverage the fact the we don’t need drum pads, sensors, a frame, or a brain to work; it just needs our machined sticks, a webcam, and access to the webapp. This provides access to drum sets to many individual who would otherwise not be able to play the drums.

We are currently on schedule and hope to receive our ordered part soon so we can start testing/experimenting with the actual project components as opposed to the various simulators we’ve been using thus far. Below are a few images showing some of the progress we’ve made this week:

(The webapp UI –>  link to view image here)

(The dot simulation)

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Ben Solo’s Status Report for 9/21

My time this week was split between preparing for the proposal presentation I delivered on Monday, determining design/implementation requirements, and figuring out exactly what components we needed to order, making sure to identify how components would interact with one another.
The proposal was early on in the week, so most of the preparation for it was done last week and over the last weekend. Sunday night and early on Monday, I spent the majority of my time preparing to deliver the presentation and making sure to drive our use case requirements and their justifications home.

The majority of the work I did this week was related to outlining project implementation specifics and ordering the parts we needed. Elliot and I compiled a list of parts, the quantity needed, and fallback options in the case that our project eventually needs to be implemented in a way other than how we are currently planning to. Namely, we are in the process of acquiring a depth sensing camera (from the ECE inventory) in the case that either we can’t rely on real-time data being transmitted via the accelerometer/ESP32 system and synchronized with the video feed, or that we can’t accurately determine the locations of the rings using the standard webcam. The ordering process required us to figure out basic I/O for all the components, especially the accelerometer and ESP32 [link]  so we could make sure to order the correct connectors.

Having a better understanding of what our components and I/O would look like, I created an initial block diagram with a higher level of detail than the vague one we presented in our proposal. While we still need to add some specifics to the diagram, such as exactly what technologies we want to use for the computer vision modules, it represents a solid base for conceptually understanding the interconnectivity of the whole project and how each component will interact with the others. It is displayed below.

Aside from this design/implementation work, I’ve recently started looking into how I would build out the REST API that needs to run locally on the user’s computer. Basically, the endpoint will be running on a local flask server, much like the webapp which will run on a remote hosted flask server. The user will then specify the IP address of their locally running server in the webapp so it can dynamically send the drum set configurations/sounds to the correct server. Using a combination of origin checking (to ensure the POST request in coming from the correct webserver) and CORS (to handle the webapp and API running on different ports), the API will continuously run locally until it receives a valid configuration request. Upon doing so, the drum set model will be locally updated so the custom sound files are easily referenceable during DrumLite’s use.

Our project seems to be moving at a steady pace and I haven’t noticed any reason we currently need to modify our time line. In the coming week, I plan to update our webapp to reflect the fact that we are now using rings to create the layout of the drum set as opposed to specifying the layout in the webapp as well as getting very basic version of the API endpoint locally running. Essentially, I want to get a proof of concept of the fact that we can send requests from the webapp and receive them locally. I’ve already shared the repo we created for the project with Elliot and Belle, but we need to come up with how we plan to organize/separate code for the webapp vs the locally running code. I plan on looking into what the norm for such an application is and subsequently deciding whether another repo should be created to house our computer vision, accelerometer data processing, and audio playback modules.

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Team Status Report for 9/21

This week our team took a closer look at planning and strategizing around the implementation process for building DrumLite. In preparation for the Design Presentation, we focused our energy on identifying design requirements and how they connect to the defined use case requirements as well as starting to nail down the specifics of how our components will interact.

We identified 4 main risks we foresee in the near future:
1.) Interfacing between the MPU-6050 accelerometer and the ESP32 Bluetooth transmitter
2.) Processing the data relayed from the accelerometer through the ESP32
3.) Inability to accurately detect the rings that define the drums location using OpenCV.
4.) Not being able to detect objects within frames fast or accurately enough given the field of view of the camera.

For each, we came up with mitigation strategies, all of which are outlined below:
1.) In the case that we can’t interface between the two devices mounted on the drumstick, our contingency plan is to completely back away from the use of the accelerometer and pivot to a new design using strictly computer vision. It is for this reason that we are currently in the process of ordering both a camera with depth sensing, and a standard webcam. The idea is that if we need to, we can resort to detecting a hit by determining the distance of the stick from the camera, knowing the distance of the camera from the desk. We don’t view this as a probable outcome as there is a lot of existing documentation we’ve seen involving the interconnectivity of the MPU-6050 and ESP32 .

2.) If we can’t figure out how to process the data relayed by the ESP32 via Bluetooth, our idea is to fall back on wiring. In this case, the wireless aspect of the project would be eliminated, but this would still stay within the parameters outline by the use case, namely portability and versatility.

3.) If we are unable to accurately determine the location of the rings using standard object such as with the HoughCircles library we were planning on using, the plan is to fall back on a convolutional neural network. Our concern with this is that using a model will introduce a lot of latency into the system, which again, goes against our use case requirements.

4.) In the case that we can’t detect the location of the stick’s tips accurately or fast enough we plan on enforcing a fixed camera height and angle, as well as a much smaller maximum layout size for the drum set. By enforcing that the camera needs to be directly above and downwards facing, capturing the exact shape, size, and location of the drum rings will be much easier and standardized.

In addition to this planning, we’ve also placed our order for all the hardware components well need, all of which were found on amazon at a reasonable price ($264). We’ve decided that in the coming week Elliot will be working on figuring out the interconnectivity of the accelerometer, ESP32, and the code required to receive and process the accelerometer data; Belle will look into figuring basic utilities in OpenCV and the effectiveness of the HoughCircle Library we plan on using for detecting the rings; Ben will be responsible for looking into how to create a REST API that runs locally and interfaces with a webserver for sending and receiving custom drum set layouts.