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

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

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.

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.

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.

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

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

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

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.

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

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

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

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

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

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

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

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.

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

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

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

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).

Thank you for listening! Any Questions?