Summary

This project is a proof-of-concept device that transmits an audio signal using a laser beam, while removing the need for the user to align the beam themselves.

Description

A mono-axial transmitter/receiver setup is created that converts an analog audio signal, via a standard 3.5mm jack, and transmits it via a laser to a receiver, which converts the signal back into audio. The receiver can be rotated within its horizontal plane, and uses a servo motor controlled by a micro-controller to automatically align it with the receiver. The end result is a wireless audio signal that cannot be “overheard”by other devices. Entire project can be divided into 2 sections:
  • audio transmission via hardware
  • alignment control via software
The above two tasks are mutually dependent for overall functionality. The alignment is accomplished using a servomotor to rotate the transmitter until it aligns with the receiver. This is done by detecting the light emitted from the receiver’s laser using a phototransistor. The transmitter scans over its free range until it finds the receiver, at which point the transmitting laser is turned on and the audio signal is picked up by an array of photodiodes.

Assumptions

Assumptions are not defined for this project.

Duration

Duration is not defined for this project.

References

References are not defined for this project.

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