Digital Notetaker Walter Jordan Tom Warsaw Senior Design Project EECC 657

Project Objectives Allow any standard whiteboard to be used as an electronic whiteboard Capture all whiteboard strokes digitally to PC Save as digital image to PC file

System Diagram

Sensor Strip

Marker Sleeve

Specifications Resolution: within 5 mm of actual marker displacement Precision: 2.5mm per pixel Accuracy: judged at least 90% as readable as original writing (est. 50 samples/sec required) Range: 1.25 x 1.25 meter whiteboard surface Time: PC must display captured strokes within 1 second of being written

Analytical Component Marker position calculated using time difference observed between simultaneous IR and ultrasonic chirps Triangulated from two receiver locations:

Analytical Component (2) Will read marker position at > 50Hz For accurate representation of motion 5mm accuracy for readability Time difference will need error less than 2.5mm precision The marker tip corresponds to 1 pixel on screen

Recalibration Accounts for variance in speed of sound User prompted to place marker at predefined positions System calculates time/distance factor for current room temperature and pressure

Division of Work Walter: Sensor testing Circuit assembly Mounting board construction Tom: Software – Java application HC12 assembly program

Work Progress Completed Acquisition of system components Software: basic structure, GUI Ultrasonic sensor testing Outstanding Software: serial port interface HC12 assembly program Infrared sensor testing Circuit assembly Mounting board construction Complete system assembly System testing

Description of Completed Work Purchased: Ultrasonic receivers (APC 40R-10A/W) Marker sleeve Software: GUI Basic program structure

GUI Design

Java Software Class Structure

Test Plan - Components Circuits The sensor receiver circuits be tested individually, using oscilloscope to check waveforms. They will then be mounted to whiteboard and tested to determine noise sources and maximum board size. M68HC12 A terminal program will be used on a PC to view the serial port outputs of the HC12. PC software A test program will be used to generate data points for the program and observe the resulting marker strokes.

Test Plan – Total System Words and diagrams will be written on board; digital image will be evaluated for readability A meter stick will be used to make tick marks 1.5 cm apart; the computer image will be evaluated to make sure marks resolve into separate points and occur at consistent distances. Recalibration will be checked with bad values to verify the negative impact

Questions ?

Performance Total power consumption Marker stylus – 1.5V N-cell battery All other components work off wall outlets Potential safety problems Toxic marker fumes

Performance – System Cost Total system cost - $ marker stylus - $50 2 APC 40R-10A/W sensors - $15 1 Optek OP954 sensor - $0.55 M68HC12 microprocessor – $150 Serial connection cable - $15 Resistors, Capacitors, Op-amps, Transistors, Diodes - $5 Mounting board - $5