Bluetooth Chatphone

Student: Simon Lu

Supervisor: Neil Bergmann

Category: Engineering Thesis Project - Computer Systems

Many chat programs today have the capability of voice chat via headsets. The Bluetooth Chatphone is designed to replace the headset with a wireless interface to the PC using Bluetooth technology. This abstract focuses on the hardware aspects of this group project.

The Chatphone consists of a normal cordless hand-set (Bluetooth-enabled), which encases a Codec and the BlueMod. The Codec is used to convert analog signal into digital signal with a sampling rate of 8 kHz and the digital output is in 2s complement 13-bit linear PCM format. The BlueMod is a Bluetooth-qualified Single Board Computer, which runs uClinux operating system on an embedded 32-bit 50 MIPS CPU with 8MB of SDRAM and 2MB of Flash memory. Through the use of BlueMod's auxiliary connector, the PCM signals are transmitted and received on air in CVSD format at a signal-to-noise ratio of approximately 30dB. Also via the auxiliary connector are the control signals that will be used to communicate between the Chatphone and the PC. The receiver-end follows the same procedures but in reverse order. The Chatphone initiate and receive calls by using either speed dial buttons or by voice activation software, which interacts with the PC via voice conference software and uses ring tones to alert users.

The construction and testing of the Chatphone is at its final integration stage, with complete hardware functionality demonstrated (voice over BlueMod, pushbutton and ring tone capability) and chat software operational. The project will be completed in time for demonstration.

Thesis Document (PDF)