Digitala projekt, 2007
Usb DAta Acquisition Card
By: Bernhard Mayr and Joe Evans
Data transfer between a pc and a connected peripheral device is done in recent times through the USB interface. Although USB has been available since 1994 and is a very popular interface at PCs, compared to the simple RS232 – serial interface, it’s implementation is much more difficult. Most people would rather buy a finished USB module and mount it on there device. However, in this project our goal is to implement and build a USB node from the scratch.
When connected to a PC, the PC should be able to detect our device as a USB device. Generally speaking, the PC can only see a connected device as a USB device only if the device has implemented and met all the requirements of the universal seriel bus standard (USB), otherwise the PC would not recognise it as a USB device.
Our finished Usb Data Acquisition Card is recognised by the PC as a legitimate USB node. The device is able to transfer data acquired through the ADC ports in the Atmega32 to the the PC. And, data sent from the PC to the device is stored in the device's USBN9604 integrated USB Node controller's FIFO. The visible serial interface (RS232) was mainly used for debugging the device in real time. The USB socket is to the left of the picture shown below.
Downloads:
Complete Project folder with source [ZIP]
USB papers and master thesis about USB (german) [ZIP]