Team E7: The Wand Makers

Carnegie Mellon ECE Capstone, Spring 2025 — Sharon Lai, Olina Zhang, Nadia Palar

Category: Team Status Reports

Team Status Report for 4/12/2025
Posted by : hsuanjul Team Status Reports

Risks and Contingency Plans

  • Firmware Compatibility Issues : The updated firmware is compilable on different machines and we were able to successfully flash the firmware to the new PCB. However, functional issues may still occur after further testings. So far we have been able to fix the bugs, but if the plan doesn’t work, we would move back to the original firmware and build upon that.
  • Model Robustness: We reduced the data collection time of the wand to 1.5s (was 8s). This change was meant to make the device more user friendly. However, model performance became much worse than before even the validation accuracy remains high during training. We are working on capturing more data, and worse case we can increase the data collection time.
  • Verification and Validation: We are testing whether the 1.5s data collection window supports accurate gesture classification. Verification focuses on evaluating accuracy, and response time to ensure the model meets MVP requirement. For validation, we are running end-to-end tests to confirm that real user interactions with the wand reliably trigger correct IR outputs.

Design Changes & Impact

There is no design changes at this point.

Schedule Updates

No major changes were made and the schedule remains as is.

Progress / Photos

Wand (Everything put together):

Wand controlling the TV in 1300 coves with cloned signal

Please see the project GitHub.

Team Status Report for 3/29/2025
Posted by : hsuanjul Team Status Reports

Risks and Contingency Plans

  • Firmware Compatibility Issues : The updated firmware is compilable on different machines and we were able to successfully flash the firmware to the new PCB. However, functional issues may still occur after further testings. So far we have been able to fix the bugs, but if the plan doesn’t work, we would move back to the original firmware and build upon that.
  • Product quality : The prototype we currently have may break after a lot of trials. We have been collecting data to train model using our version 1 PCB, and noticeable damage has been caused (one of the buttons is no longer sensitive and the battery port is falling off. We are trying to do most of the testing and trainings on version 1 PCB and development board so that our version 2 PCB remains new.

Design Changes & Impact

There is no design changes at this point. We are working on integrating everything and preparing for the interim design review

Schedule Updates

No major changes were made and the schedule remains as is.

Progress / Photos

Fixed wand button: https://youtu.be/jqVDue59yyQ

New PCB (with close up of through-hole for wire connection to IR LED):

Please see the project GitHub.

Team Status Report for 3/22/2025
Posted by : yunjiaz Team Status Reports

Risks and Contingency Plans
We completed fine-tuning the firmware this week and began integration testing. So far, the system appears to be functioning as expected. Firmware remains the most critical component, but with the recent fine-tuning, we are more confident in its stability.

Design Changes
There are no changes to the design at this stage.

Schedule
We remain on schedule.

Team Status Report for 3/15/2025
Posted by : hsuanjul Team Status Reports

Risks and Contingency Plans

Although there haven’t been a lot of major changes to the updated PCB, we might still encounter bugs when integrating it with the new PCB. At this point the most vulnerable part of the project is the firmware, and Nadia and Sharon are devoting most of the time to it. The old version of firmware is rather stable, so in the worst case where we are not able to completely debug the new firmware, we would make minor modifications on the old firmware.

Design Changes

No changes to our design at this point.

Schedule

We remain on schedule.

Team Status Report for 3/8/2025
Posted by : npalar Team Status Reports

Risks and Contingency Plans

Our biggest concern at this point is ensuring we can successfully integrate before the interim demo. To mitigate this, we will extensively test our individual parts to minimize the amount of sources of error before attempting to integrate onto our custom hardware in the coming weeks.

Design Changes

No changes to our design at this point.

Schedule

We remain on schedule.

Part A (Olina Zhang)

Our product addresses global needs by providing a simple, accessible solution to interact with IR-controlled devices, offering an affordable and user-friendly option without the need for sophisticated or expensive smart home infrastructure. The processes to clone and transmit signals are simple and easy to learn, and the use of clear gestures makes it ideal for non-technologically savvy users. In this way, our wand can bridge the gap for people who may not be familiar with traditional remote controls or more complex voice-activated systems.

Part B (Nadia Palar)

In a cultural sense, our wand is designed to be easily used since it does not inherently rely on languages or symbols specific to any culture. The gestures themselves do not have any specific intonation or meaning since they were chosen chiefly for their optimality with regards to detection instead of any cultural meaning. Further, the wand’s simplicity in design is also intuitive enough for individuals who may not have prior exposure to high-tech gadgets.

Part C (Sharon Lai)

Our wand offers a more environmentally friendly approach than typical remotes because it uses a rechargeable battery. Typical remotes for IR controlled devices use disposable batteries which in turn constitute electronic waste. In a global context where environmental sustainability is becoming increasingly important, our product solution contributes to minimizing the carbon footprint associated with the overproduction and disposal of electronic products, offering a cleaner alternative to traditional methods of controlling devices.

Team Status Report for 2/22/2025
Posted by : yunjiaz Team Status Reports

Risks and Contingency Plans

The most significant risk right now is that our model evaluation is behind schedule, which may delay integration with the IR wand system. Since we need to compare CNN, RNN, and LSFM models before finalizing one for deployment, delays in testing could impact our further implementation and optimization.

To mitigate this risk, Olina will prioritize completing model evaluations next week and continue working during spring break weekend to ensure we stay on track.

Design Changes

No changes to our design at this point.

Schedule

We are behind schedule due to delays in model testing. However, we are working to catch up next week and will use spring break to ensure we meet our project milestones.

Team Status Report for 2/15/2025
Posted by : npalar Team Status Reports

Risks and Contingency Plans
The most significant risk right now is if our ordered PCB doesn’t work after being ordered because there may not be sufficient slack to redesign and order another PCB after receiving our V1. As such, we are spending substantial time verifying the PCB design before ordering it. Additionally, there are multiple test points on the boards in case hotfixes are required.

Design Changes
No changes to our design at this point.

Schedule
We remain on schedule.

Part A (Olina Zhang):
Our wand-based gesture detection and infrared control technology benefit public health, safety, and welfare in a variety of ways. Our technology eliminates the need for physical switches, which improves safety. It offers a touch-free interaction technique, which reduces the spread of viruses and impurities on frequently handled objects like light switches and TV remotes.This is ideal for persons with restricted mobility, disabilities, or the elderly, who may struggle with traditional remote-controlled devices. The technology allows people to easily control their surroundings with simple gestures, reducing the risk of falls or accidents caused by reaching for physical controls.

In terms of welfare, our product strives to improve people’s quality of life. We want to create a wand that is small, simple to use, and provides consistent results. Our technology provides convenience to a wide spectrum of consumers. This promotes independent living for people with physical disabilities and enhances comfort and usability in smart homes.

Part B (Nadia Palar):
The wand provides a unique and expressive experience for individuals to interact with their technological devices. The wand also gives individuals a way to interact with devices in a more meaningful way as well as express an interest in magic. One such social context in which this might be particularly of note is in the classroom, where the wand could be used to make lessons and engaging with educational material more interactive and appealing for some students.

Part C (Sharon Lai):
One of the primary economic considerations is the final cost of manufacturing the wand. The components involved—IMUs, IR transmitters, and CNN-powered systems—are becoming increasingly affordable due to advances in sensor technology, machine learning, and miniaturization. Our approach allows us to leverage these innovations to create a cost-effective and economically viable option for individuals looking for a new and more expressive way to interact with their technological devices.

Team Status Report for 2/8/2025
Posted by : hsuanjul Team Status Reports

Risks and Contingency Plans

  • Firmware Stability & Compatibility Issues The transition from the STM32 standard library to the HAL library could introduce unexpected issues in peripheral functionality, particularly in SPI flash, I2C communication, etc. We will test each module incrementally and verify functionality before proceeding to new updates. We are also keeping backups of the standard library implementation in case of severe issues. If the HAL library causes critical instability, we will explore using a hybrid approach—keeping some standard library components for specific modules while migrating the rest to HAL.
  • Gesture Recognition Model Accuracy Data preprocessing steps (e.g., normalization, filtering) need to be refined. And we plan to do more research into CNN and other architectures.

Design Changes & Impact

  • Watchdog Timer Removal & Power Management Adjustments During firmware debugging, it was confirmed that all four MCU timers (TIM1-TIM4) are already allocated for other tasks, meaning the watchdog timer cannot be used for power optimization. this means that the system will need to rely more on hardware-based power management rather than software-based sleep modes. However, since the MCU is already low-power, this change should not significantly impact energy efficiency. We will still optimize the circuit design to minimize unnecessary power consumption.

Schedule Updates

No major changes were made and the schedule remains as is.

Progress / Photos

Please see the project GitHub.