a14g-final-submission-s25-t01-double-aa-batteries

a14g-final-submission

* Team Number: 1
* Team Name: Double AA Batteries
* Team Members: Arushi Mittal and Ashley Tang
* Github Repository URL: https://github.com/ese5160/a14g-final-submission-s25-t01-double-aa-batteries.git
* Description of test hardware: (development boards, sensors, actuators, laptop + OS, etc)

1. Video Presentation

Video Link

2. Project Summary

Device Description

The Guitar Buddy is an assistive guitar trainer helping people with accessibility needs learn how to play the guitar through visual and tactile prompting. The Guitar Buddy has large buttons that the user can press as opposed to having to pressing multiple strings to play chords, as well as with an assitive guitar pick holder with haptic feedback of when to strum the strings and uses IoT as the user interface, allowing the user to select modes and view feedback, creating a more friendly user experience.

Device Functionality

The device has four major components – an LRA (linear resonant actuator), accelerometer, pressure sensors, and LEDs. The LRA is used in the assistive guitar handle and prompts the user to strum the guitar strings whenever it buzzes. The accelerometer is used to provide positioning feedback on how the guitar is being held. Finally, the LEDs visually prompt the user to play a specific chord, and the pressure sensors detect if/when the chord is pressed.

System Block Diagram:

Challenges

Although we created a mechanical user interface that would be easy to use, it was harder to implement than we thought. We also sent our prints and due to the end of semester rush, we did not recieve them until the night before demo day. Although our mechanical components were unable to work with the device as expected, we were still able to create a functional prototype that demonstrates proof of concept.

Prototype Learnings

From making the prototype, we learned a lot about PCBA board bring up, specifically in creating the bootloader. We were also very fortunate that we did not face many manufacturing challenges, but this experience taught us the importance of strong PCB design. We gained more experience working with JLink programming and working with a variety of communication protocols, including I2C and SPI. Finally, we learned a lot about cloud communication through our development with Node-Red.

Next Steps & Takeaways

In the future we would love to create a more robust mechanical interface so that pressing the buttons would allow the user to play chords. Electrically, we would also like to include a speaker on our device so that we could also audibly prompt the user what chord to play. The speaker could also play the sounds of the chords, transforming the device into a portable electric guitar, allowing multiple modes of play.

Project Links

Node Red Dashboard

Altium Project

3. Hardware & Software Requirements

Hardware Requirements (HRS)

HRS 01: The device shall be based on the SAMD21 microcontroller for the main system and the ESP32 microcontroller for the guitar pick interface.
HRS 02: The system shall use a LiPo battery (3.7–4.2V) for power, with a boost circuit (5V) and buck circuit (3.3V) for appropriate voltage regulation.
HRS 03: Pressure sensors shall detect button presses (simulating playing chords) and transmit data to the MCU using ADC (Analog-to-Digital Conversion) pins.
HRS 04: The device shall include a Wi-Fi controller (WINC 1500) for IoT connectivity.
HRS 05: LEDs shall be included to prompt the user, indicating the chord to be played.
HRS 06: The system shall include a haptic module (linear resonant actuator) integrated into the guitar pick to prompt strumming actions wirelessly.
HRS 07: The system shall incorporate on/off buttons for user control over power and WiFi connectivity.
HRS 08: The guitar attachment shall house all essential sensors and actuators, detachable from the guitar for portability.
HRS 09: The device shall have a speaker for audible prompting functionality, enabling voice-based instructions during training modules.
HRS 10: The on-board accelerometer shall sense and transmit the guitar’s orientation, to provide feedback to the user for correcting the orientation of the guitar.
HRS 11: The PCB shall include proper shielding to minimize interference between wireless communication and other components.

Software Requirements Specification (SRS)

The device allows the user to choose between two modes. The first mode is loading specific songs from the online dashboard and prompting the user to play the chord and strum. The second mode is a “free compose” mode where the user can play chords and strum the guitar, and the online dashboard records the chord and strumming pattern, effectively allowing the user to compose their own music.

SRS 01 – When the user is using “playing mode”, the device can light up an LED under a button, based on the user’s selected chord, prompting them to play the chord
SRS 02 – When the user is using “playing mode”, the device sends a signal to the adaptive guitar pick to prompt the user to strum the guitar
SRS 03 – When the user is using “playing mode”, the device is able to prompt the user to play chords and strum the guitar based on the chords and strumming patterns of a song
SRS 04 – The user can load songs to play on the device and the device prompts the user to play the chords and strum patterns
SRS 05 – When the user switches the mode of the device, the online dashboard will reflect which mode the user is using
SRS 06 – When the user is using “composing mode”, the dashboard will record which cord is being played and the strumming pattern of the user.
SRS 07 – The device users the accelerometer data to provide feedback to adjust guitar orientation.
SRS 08 – The device prompts the user using vocal cues from the speaker.