Phased Speaker Array : Phase of Our Lives Dave Simley and Rosemary Montgomery Group #68 ECE 445 - Senior Design

Table of Contents Objective Introduction Design Physical Design Conclusion

Objective Music can really brighten the mood, but interference patterns greatly affect the quality of the sound. Our design is a phased speaker array that can reduce these interference patterns When the music is phase corrected, the listener would hear their music at a considerably louder volume and with a richer tone Add graphs from matlab @dave? -Better explain steering -talk about range of product (podcasts, audiobooks, etc.. Or educational) -”set the scene”

A Phased Speaker Array… Detects the location of a person in a room “Steers” the sound towards the listener by Calculating the appropriate time delay and Sending delayed signals to the speakers -Better explain steering -talk about range of product (podcasts, audiobooks, etc.. Or educational) -”set the scene”

Block Diagram

Design: Modules Signal Input: ADCs convert the input analog signal into digital values IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C Control: Microcontroller processes the information and outputs delayed signals. The DACs then convert the digital values back to analog signal. Speaker Array: Amplifies the signal and sends it through four speakers

Design: Signal Input Module An analog-to-digital converter (ADC) constantly samples an analog input Interfaces with MCU sends over digital value of input signal Analog Input (-5 to +5V) Digital Output (0x000 to 0xFFF) Source: [5]

Design: Modules Signal Input: ADCs convert the input analog signal into digital values IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C Control: Microcontroller processes the information and outputs delayed signals. The DACs then convert the digital values back to analog signal. Speaker Array: Amplifies the signal and sends it through four speakers

Design: IR Receiver Module Interface: I2C Detecting distance: 0~3m FOV: 33 degrees Potentiometer alternative for manual operation Source: [1]

Design: Modules Signal Input: ADCs convert the input analog signal into digital values IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C Control: Microcontroller processes the information and outputs delayed signals. The DACs then convert the digital values back to analog signal. Speaker Array: Amplifies the signal and sends it through four speakers

Design: Control Module – Microcontroller Inputs: IR tracking information Digital input sample from ADC Operations: Calculates time delay for four signals Sends digital values of the delayed samples to the DACs A timer interrupt tells the DACs to update Another timer interrupt updates the location information of the IR source Source: [3]

Design: Modules Signal Input: ADCs convert the input analog signal into digital values IR Receiver: Detects IR source in the room and sends the location to the microcontroller via I2C Control: Microcontroller processes the information and outputs delayed signals. The DACs then convert the digital values back to analog signal. Speaker Array: Amplifies the signal and sends it through four speakers

Design: Speaker Array Module Power amps Capable of delivering up to 10W Has adjustable gain Speakers 4 inch, 8Ω speakers 150Hz-20kHz Source: [4]

Physical Design The speakers were placed 23.3cm apart Allows for 3° of accuracy when steering the signal

Conclusion What worked: Interfacing between modules Ability to delay signals and actively follow listener Effect was noticeable when playing a single tone

Conclusion Future work: Incorporate better tracking system Current project has intuitive interface for this as a separate module Faster microcontroller Experiment with different delay algorithms More stable connectors between modules

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