Experimental Microphone for the ATM Warren


This electronic microphone contains an integral ADC convertor and ATM line interface. When power is applied, a continuous stream of audio cells is generated.

Audio Specifications

Sample precision: 16 bit mono
Sample rate: 44.1 ksps
Cell rate: 3675 cells per second.

ATM Cell Format

Header : GFC=0, VPI=0, VCI= 48, PT=0, CLP=0 Payload=12 Samples of 16 bit audio, each sample repeated to generate a stereo compatible stream from a mono source.

Application Examples

Hands-free phone
Baby Monitor
Door Entry Phone
Public Address
Voice activated control

The Warren Project

The ATM Warren Microphone is an experimental hardware device being developed at the University of Cambridge Computer Laboratory as part of the Warren Project. The Warren project is funded by Virata and has the aim of developing a set of low-cost ATM devices, including an ATM switch.

Pin Connections

RJ45 modular jack:
1 TX +
2 TX -
3 NC
4 DC 0 Volts
5 DC +7.5 to 15 Volts
6 NC
7 NC
8 NC

The ATM Warren Project
University of Cambridge
Computer Laboratory
New Museums Site
Pembroke Street
Cambridge CB2 3QG