1.Obtain laser pointer coordinates 2.Send laser pointer coordinates to laptop through the PS/2 port 3.Pixel Mapping between camera image and laptop screen & calibration 4.Attach a button to the laser pointer Four major components to laser mouse

Overview of Design Use Camera Interface Send Images to FPGA LaserSpot module Analyze each image for brightest spot Use Xbus interface Send coordinates to Controller Use Windows pen drivers Perform coordinate translation Use PS/2 interface Send coordinates to laptop Camera taking constant images

1. Obtain laser pointer coordinates How to track the laser point? Color mapping to eliminate colors below a brightness threshold Upgrades to improve correctness – Multiple bright pixels in one area Current VGA Display

1. Obtain laser pointer coordinates LaserSpot – Find the brightest pixel as data is being written to memory. CrossHairs – As data is being written to the VGA, blank out all pixels except the brightest and draw the crosshairs on the row and column with the brightest pixel. Normal Camera Interface

2. Send coordinates to the laptop Controller to laptop through the PS/2 Port Problems: Difficult to find documentation Modify driver to use absolute coordinates Strategy: Use Xbus interface to Controller Use standard PS/2 protocol

2a. Send coordinates to Controller Xbus Interface to connect FPGA and Controller Use Xbus interface designed in class

2b. PS/2 Mouse Port Protocol 8 data bits, least significant bit first. 01 Must send 3 consecutive data packets to move mouse Packet 1 => Mouse click info and movement info Packet 2 => new x position (absolute position) Packet 3 => new y position (absolute position)

2b. PS/2 Mouse Port Protocol Composition of each data packet: Packet 1 Format: Overflow bits (2), X & Y direction (2), Right & Left mouse click (2), Fixed (2) Packet 2 Format: X direction movement Packet 3 Format: Y direction movement Inputs & Outputs of Controller implementation in software: Input: FPGA coordinates, Mouse click Output: Data to PS/2 port, PS/2 clock ( sec) External: Pixel Mapping, eliminate laser pointer shaking (both may be able to be implemented in the driver)

3. Pixel mapping Camera Image of Projection Screen Laptop screen 256x256 pixels 640x480 pixels? 800x600 pixels? 1024x768 pixels? Pixel mapping & calibration done in the driver

3. Pixel Mapping Calibration –Perform a calibration program before starting to use the laser pointer as the mouse. Similar to Palm calibration program. The Windows driver is the Unidriver –Pen Calibration: PENCAL.DLL Pixel Mapping –Moving the laser pointer 1 foot on the projection screen means moving the mouse x pixels in the camera image which is y pixels on the laptop screen. What are x and y? –Virtual device driver: VPENDC.VXD –Pen driver: PENC.DRV

4. Attach a button How to connect the button to the Controller? Wire Radio Frequency Camera interface Laser Pointer Kit The mouse click will be transmitted in Packet 1 of the PS/2 Protocol.

Conclusion 1. Laser spot tracking - functional, upgrades pending 2. PS/2 mouse port – this week (week 7), continual upgrades 3. Pixel mapping – weeks 8 & 9, continual upgrades 4. Laser button – week 9 & 10

Any Questions?