This project is a development of a USB device which can act as both mouse and a scanner. The device is intended to be a mouse which can also be used as a scanner. The device had a button to switch between mouse and scanner modes.

The device had a monochrome image sensor at the bottom of the mouse which captures the image over which it is moved. The movement of mouse roller generates pulses which determine the scan interval for the image sensor. Before start of scanning, the device identifies the threshold setting for the document. Threshold is set based on the amount of light reflected by the document. Based on the threshold value, the output of scanner is taken an either a white or black pixel. The scanned image is read by a micro-controller and transferred to PC via USB. The image sensor, mouse and the micro-controller are connected to an FPGA (XC3042A Xilinx chip). The FPGA design handles the signal/data exchanged between the components.

When the scanner image is received in PC by the USB device, the PC side software converts the scanned image to text using customer supplied Optical Character Recognition (OCR) software. The scanned text is then either copied to clipboard or sent to the active cursor position based on User selection.

The block diagram of the device is shown below:

Device description

The block diagram of the FPGA module is shown below:

The scanner device consists of image scanner, LCD display and mouse keys. For communication between PC and the device, USB cable is used. The image sensor is line scan type. Dyna The sensor is of 57mm size. The LCD module has 128 X 64 full dot matrix configuration and has two 4096-bit internal display data RAMs.

User Interface

The mouse scanner system has a USB side PC interface to control the functions of the device. Snap shots of the user interface components are shown below: