1. ECE 477 Final Design Review
Team 14 – Air Drums
Liang Chao Anthony Kang Kerrie Spaven Cyrus Sutaria

2. Outline Project Overview Block Diagram Design Challenges
Individual Contributions
Project Demonstration
Questions

3. Project Overview Portable drumming solution
Accelerometer detects user motions in space as hits
Joystick on drumsticks determine sound/drum played
Bluetooth connection between drumsticks and Android application
In this section provide a concise description of your project. What is it? What does it do? Include a relevant picture of your project or “artist rendering” of the completed project.
Air Drums are a convenient method of bringing live music on-the-go. The specialized drumsticks detect the user’s movement in space, sending a Bluetooth signal to an application on an Android phone, which will output a specific sound (of a certain drum). On the drumstick there will be a toggle switch allowing the user to change what drum or cymbal they would like to virtually hit. This application allows the user to play over existing music, record their current session, and will also show the remaining battery life on the drumsticks. In addition to generic drum set sounds, the user can download different sounds and effects to each button, so that he or she can express their artistic feelings more freely.

4. Block Diagram IO SPI UART I2C Bluetooth Module Accelerometer
Microprocessor
Battery Monitor
Voltage
Regulator
Battery Charger
USB Port IO
SPI
UART
I2C
Lithium Ion
Block Diagram
Liang
Include one or more images of your system block diagram here. Block diagrams should include all relevant major parts and systems, bus widths, and interface types.

5. Design Challenges PCB Voltage Regulator Bluetooth Battery Monitor
Accelerometer
Packaging
Liang
In this section, detail major design challenges your team faced in developing your project. These could be conceptual challenges, such as fitting a complex design into a small form factor. Alternatively, these could be implementation challenges, such as difficult hardware and software errors which took many many hours to debug.

6. Design Challenges PCB Has to be small enough to fit inside a drumstick
Traces must be thin but wide enough for power
Hard to squeeze all components in
Connections get complicated with multiple components
Some components powered by battery voltage, some by regulated voltage
Pads are small + fragile
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging
Liang

7. Design Challenges PCB Has to be small enough to fit inside a drumstick
Traces must be thin but wide enough for power
Hard to squeeze all components in
Connections get complicated with multiple components
Some components powered by battery voltage, some by regulated voltage
Pads are small + fragile
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging

8. Design Challenges Voltage Regulator PCB Voltage Regulator Bluetooth
Battery Monitor
Accelerometer
Packaging
Seems to be our easiest component to break
Didn’t regulate the voltage to be a constant 3.3V.
If the voltage regulator was not working, then none of our components would work.
Cyrus

9. Design Challenges Voltage Regulator PCB Voltage Regulator Bluetooth
Battery Monitor
Accelerometer
Packaging
Seems to be our easiest component to break
Didn’t regulate the voltage to be a constant 3.3V.
If the voltage regulator was not working, then none of our components would work.

10. Design Challenges Bluetooth PCB Voltage Regulator Bluetooth
Battery Monitor
Accelerometer
Packaging
Significant amount of latency in the link
Could try a faster micro -> BLE rate
Trouble receiving responses in a useable form from BLE
Cyrus

11. Design Challenges Bluetooth PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging
Significant amount of latency in the link
Could try a faster micro -> BLE rate
Trouble receiving responses in a useable form from BLE

12. Design Challenges Battery Monitor
Difficult time getting it to acknowledge back
When we did get it to acknowledge back, we had a hard time talking to it (reading and writing)
Timing issues with interrupt
Datasheet very limited
Two bad chips
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging
Anthony

13. Design Challenges Battery Monitor
Difficult time getting it to acknowledge back
When we did get it to acknowledge back, we had a hard time talking to it (reading and writing)
Timing issues with interrupt
Datasheet very limited
Two bad chips
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging

14. Design Challenges Accelerometer Not as sensitive as we hoped PCB
Not reliable
Often have to reprogram the chip multiple times, with the same code, to get it to function properly
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging
Anthony

15. Design Challenges Accelerometer Not as sensitive as we hoped PCB
Not reliable
Often have to reprogram the chip multiple times, with the same code, to get it to function properly
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging

16. Design Challenges Packaging
Didn’t know exact size of PCB until later mid way through the semester
3D printing is not 100% accurate
Filler makes the orientation of printing critical
Waiting in queue
Failed prints
PCB
Voltage Regulator
Bluetooth
Battery Monitor
Accelerometer
Packaging
Kerrie

17. Individual Contributions: Kerrie Spaven
Helped with part selection & purchase
Packaging for drumsticks
Soldering components to PCB
Debugging PCB
Hardware
Debugging PCB schematic
Making changes for 2nd board
For each member of your team, detail his/her individual contributions to the project. Each student should be prepared to speak for ~1 minute regarding their contributions to the project.

18. Individual Contributions: Liang Chao
System design
Part selection + purchase
System schematic
PCB design + purchase
Populating board
Debugging PCB, hardware
Fixing packaging

19. Individual Contributions: Anthony Kang
Worked with accelerometer and hit detection
Debugged PCB and soldered on components
Worked with battery monitor
Helped Cyrus with Bluetooth
Worked on Android Application
Wrote Micro Firmware Code

20. Individual Contributions: Cyrus Sutaria
Helped with part selection
Portion of the system design
Helped with debugging sensor interfacing
Bluetooth Low Energy development
Android Application
Peripheral integration

21. Project-Specific Success Criteria
An ability to determine and display battery remaining in drumstick
An ability to detect drum hit gestures using the accelerometer
An ability to operate Bluetooth module to successfully transfer meaningful (the ability to relay drum hits or device status information) accelerometer information from drumstick to Android application
An ability to detect button presses to relay instrument changes to the Android application
An ability to load as well as trigger sound clips (various drums) from within Android application
List your PSSCs in the space below, but do not read them during the presentation. Provide a link to a demonstration video of your project in action on your team website (720p 16:9 HD on YouTube is recommended).

22. Thank you for listening!
Any Questions?