The Design Of Data Acquisition/Signal Generator Based On USB Bus

The virtual instrument gradually turns into reality since it's first been taken into consideration with the rapid development of the technologies of the computer and data processing. This article is mainly about the design of the data acquisition and signal generator base on USB bus. It is about a specific case of realizing the virtual instrument. This article first tells of the contents of the technologies of the USB bus, and use USB1.1 protocol and the USA's National Semiconductor's USBN9604 interface chip to complete the production of high-speed USB interface device. It makes the communication between PC and testing devices based on USB bus available. In the mean time, study the USB 2.0 criterion, and compare it with the USB 1.1 criterion thoroughly. And used the Cypress company's CY7C680133 interface chip to made a device interface on USB 2.0 criterion, including the hardware and the controlling program. Secondly, I use the internal 12 bits A/D and D/A convertor in the Cygnal company's new microchip C8051F007 as a core to develop the data acquisition/signal generator based on USB bus. It has the characteristics of small in size, low in power, and powered by the USB bus. The computing of the excitation and the processing of the collected data are all completed by the PC. And it makes full use of the universality and flexibility of the virtual instrument. Finally, the computer uses the embedded HID driver programs to communicate with the HID class devices by using the API functions. The software completes the design of the user-oriented USB interface testing instrument, virtual digital oscilloscope and the signal generator. The designed data acquisition/signal generator can hardly be missed in setting up a virtual instrument. The facts have proved that the virtual instrument base on that has the advantages of good performance, wide application and cheaper prices.