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Cora’s Status Report for 2/15/2025

This week I worked on making a prototype browser extension. Specifically, I made a Chrome extension which I’m running in Chrome’s developer studio (this is where I’ll be testing it until we are finished then I will upload it to the Chrome Web Store so that others can download it). Currently the extension consists simply of a button which when pressed creates an alert in the user’s system tray. In the finished extension, the alert will occur when the data from the sensors indicate poor posture, but right now I just have the user press the button to demonstrate the system tray notification functionality. In addition, I created a script which allows the user to grant camera permissions in the options menu of the extension. This is important because we need the camera for the CV eye strain algorithm. This unfortunately must occur in the options of the extension and not in the extension itself because this is not an innate function of Chrome browser extensions.

My progress is on schedule. Next week I hope to add the CV script and see if we can run it in the extension (I know that Lilly has the CV script working locally but we have not yet tested it via the extension). I also want to set up the local server on the raspberry pi since we recently got possession of the pi we will be using.

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Kaitlyn’s Status Report for 2/15/2024

This week, I focused on finalizing design choices, ordering parts, and creating the presentation slides/ document.  I spent a lot of time on the force sensitive resistors, because after our meeting with Tamal on Tuesday I realized it would make more sense to go with sensor arrays than with individual resistors – as this would lead to a lot of complicated wiring. I went with the following sensor array:

It is commonly used for measuring weight distribution when standing, and by using multiple of them, I can get a lot more measurement for the same price. Specifically, 1 individual FSR is  the same price as the 8 FSRs that come on this mat. I will not use all of the sensors (because I need to mux them in order to convert them to digital values), but I can play around with the different configurations of which sensor to use. As seen in the picture I am going to use 4 sensors from each pressure mat. From first glance, I want to use the 4 sensors in boxes, but based on testing I will do once the parts arrive, different mats will use different sensors. The current plan is to hook up 4 sensors through a voltage divider circuit into the ADC, which has an op amp amplifier. It will then get sent through I2C communications to the RasPi. I also spent time making the slides for the presentation this upcoming Monday. Outside of that, since we have our RasPi, I am also working towards putting the RasPi on the CMU Device network in order to host the server – this is a more complicated process than anticipated but I am working through it.

I am not behind schedule. This week, I accomplished ordering all of the necessary parts/finalizing BOM & beginning to start hosting the local server, which was what I wanted to accomplish. This upcoming week depending on when my parts arrive I might find difficulty finishing the work I want to do (a first test of the sensors and connecting the ADC) if the parts are delayed / the RasPi does not boot. To keep myself on track, I plan on continuing testing with a RasPi Pico in order to still be able to start writing and testing code for ADC and I2C this week, as this way I can stay on top of the sensor creation. It will also help me start working on the integration earlier.

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Team Status Report for 2/8/2025

What are the most significant risks that could jeopardize the success of the project? How are these risks being managed? What contingency plans are ready?

The most significant risks that currently exist are making design decisions which would lead to more costly or difficult integration later on down the line. In order to mitigate this risk, we plan on buying duplicates of sensors, as well as purchasing backup plan sensors in advance in order to prevent any delay between switching to a secondary plan if it needs to occur. We also plan on meeting with our TA and advisor in order to discuss our design choices and understand the risks and challenges associated with our current design. This will allow us to make any necessary pivot we need before beginning to create the project. 

Were any changes made to the existing design of the system (requirements, block diagram, system spec, etc)? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

No changes were made to the existing system so far, we have not yet solidified our design plan and thus any changes being made now are just us working our way towards a viable MVP. We have better solidified which sensors we will be using — Kaitlyn found the sensors for the chair, while Lilly researched gyroscopes for the neckband — and Cora completed research on which permissions will be necessary for our design to work on the Google Chrome extension platform. 

Provide an updated schedule if changes have occurred.

No schedule changes have occurred, we plan on creating the BOM and ordering parts this Monday, so we can begin to create and test our MVP as soon as possible. While the parts come in, we will work on setting up the RasPi and coding it in order so it can host a local server. We will then ensure we can connect to this server from an external network.

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Lilly’s Status Report for 2/8/2025

This week I focused on researching components for the neck angle measuring system, mainly the gyroscopes.

While we were initially talking about using a gyroscope for tracking neck angle, I also researched inclinometers as another option since they can be used for angle measurement too, especially in steadier conditions. It seems that inclinometers on the market are mainly intended for industrial applications and are too clunky (I’m looking for something relatively flat to avoid disturbing the user) and expensive relative to our budget. So, for something wearable I continued to focus on gyroscope sensors.

As I researched, I looked into the potential of biaxial angle tracking, as forward neck posture is not the only way a user can experience neck strain after extended work periods. Most gyros have this capability anyway. I focused on options that allowed for angle tracking along at least 2 axes (sagittal and coronal) and researched the circuitry each sensor would need to work, with the aim of selecting a sensor with minimal circuitry and accuracy within our requirements, ideally much tighter as our initial goal of +/- 5 degree measurement accuracy is quite wide. Drift in the gyros also came up as a problem, which could be mitigated by doubling up the sensors – and would allow the band to be more symmetric in terms of weight on the user. I also researched/tested the range of angular velocities that our sensor would need to handle – a maximum speed of 200 deg/sec is what I looked for. Further, while an analog gyroscope would be nice so we can control the sampling rate/resolution better, I found that digital gyroscopes will be easier to find and use. A potential option is the L3GD20 gyro, which is small, has low input voltage requirements and a good-enough range.

I am on schedule for now. Further research on wearable batteries and gyroscope part selections will be completed tomorrow before our team meeting on Monday.

Deliverables for the next week:

  • Make purchases for neckband components after cross-checking with the team (Monday).
  • Research wireless connection between ESP32 + RPI.
  • Finalize design for how the neckband will be worn by the user.
  • Start drafting code for angle calculation with gyroscope data for the ESP32.
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Cora’s Status Report for 2/8/2025

This week I focused on researching the browser extension. The browser extension is going to be used in order to allow the user to easily interact with our project and give them an intuitive UI to view their data and make changes such as toggle options for their camera being on/off and whether sound notifications are on/off.

I researched which browser would be best to make our extension for. I came to the conclusion that Google Chrome would be the best because of the thorough documentation that’s available, the APIs that Google provides, and its straight-forward development process. I researched what type of permissions we will need to ask the user for since the user being aware of what they’re installing is important to us. I wanted to establish the most minimally invasive permissions necessary so we’re not asking for more than what we need and compromise the user’s security. I established we will need at least the following Chrome permissions: audio (for audio notifications), notifications (for on-screen alerts), activeTab, and scripting (in order to adjust brightness of screen). These permissions will be listed in the manifest.json file which is part of the family of files that make up the extension. Note that the user must accept to all these permissions at installation time even if they later choose to disable related features. Otherwise, some permissions can be declared “optional” which is something I would like to discuss with my team to see if this makes more sense for our project.

My progress is on schedule for this week. Next week I hope to have a prototype extension ready in order to test out the basic infrastructure of our extension. I also want to begin with setting up the RasPi hosted server.

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Kaitlyn’s Status Report for 2/8/2025

This week, I presented our Project Proposal to the other capstone teams and faculty. I spent ~2 hours preparing for the presentation to ensure we met all the needed requirements in the slide show, and to ensure that I could spend my time interacting with the audience instead of reading just off the slides. After presenting the proposal, I spent the rest of the week doing research into different sensors we could use in the chair. I was able to narrow it down to two types of sensors: Load Cells and Flexible Force Sensors. After putting some more thought into the overall integration, I think that using flexible force sensors (image of circuit I would need below) might be better in the long run to meet the user requirements of not impeding the user during their work, as they will not be as obtrusive on the chair. While I would need an opamp and capacitors for this circuit, I think the wiring could be done under the chair to be unobtrusive. As well, those parts are very cheap and easy to replace. Since we are using the RasPi, I also researched possible ADC converter modules for the RasPi in order to digitize the voltage inputs into the Pi. I hope this upcoming Monday to finish talking through this design choice with the team and order the parts necessary to begin creating a barebones pressure mat and testing it.

 

My progress is on schedule. This week, I wanted to complete research into parts for the pressure sensors so they could be ordered on Monday when our team next meets.

In the next week, I hope to create a much more in depth design of the chairs sensors. I hope to create a document that details exactly how the pressure sensors will be connected to the raspberry pi, and begin working on the code in order to create the averages for weight distribution on the chair.