Hes-so Valais



Microcone is an intelligent microphone that can be used to record meetings. It uses a 7-microphone matrix to capture sounds from all directions and transmits the signal to a PC using a simple USB connection. Every speaker is recognised and recorded separately on its own channel.

The HES-SO Valais-Wallis was in charge of designing the electronic part of the device.

The system consists of 3 printed circuit boards:

  • an FPGA circuit and a USB interface circuit
  • a second circuit at mid-height with six microphones at regularly distributed angles and an 8-channel analog-to-digital-converter
  • the top circuit with another microphone.

The USB connection is based on a Cypress Semiconductor EZ-USB circuit. This circuit was configured to respond as a “microphone array” when connected to the PC. No driver has to be installed on the PC.

The USB connection gives the time base and the FPGA includes a PLL to set the sampling rate. It reads the audio signals from the microphones and transmits them to the USB port. The communication in isochronous mode allows the transfer of the sampled signals to this type of medium.