Design of USB Data Acquisition Card Based on CPLD

摘要

A kind of new type data acquisition card with USB interface is introduced, its hardware design solution is given. As the core of the whole system, USB interface chip receives the channel select command from host computer, then send it to analog switch matrix through I2C transfer chip and CPLD, realizes the selection of input channel. The control command sending flow is introduced in detail, and the firmware code of USB interface chip and CPLD is given. Software is designed according to USB protocol and used to send control command and receive data, which realizes the data acquisition of any a channel. This data acquisition card is adapt to be used data acquisition system which requests not very high speed, and provides a new way of low cost 、pint-sized and multi-channels data acquisition systems.