Touch Screen Linearity Tester Presented by Axis Inc.

Overview Z-Axis Mechanism Linearity and Skew Testing Protocol Physical Circuit Microcontroller User Interface Functionality

Z-Axis/Force Actuation

Linearity

Results From Manual Testing Linearity Data Confidence Intervals

Skew skew ratio =

Results From Manual Testing Skew DataConfidence Interval

Testing Protocol Force Actuation/Resistance Linearity/Skew

Physical Circuit

Voltage Divider ADC measures Voltage drop across known R1 Back Calculating To find Rtouch

Microcontroller The “Brain” of the system Receives Data from GUI Controls the Tests Reads Values from A/D Converter Sends Data back to GUI

Microcontroller (cont) Max127 A/D Converter RS232 for serial communication Motor controller card Photogates

User Interface Functionality

Action Items Data Acquisition and Control Circuit  Build and test low current circuit for data acquisition with micro controller  Streamline micro controller code  Modification to code for movement in x and y-axis simultaneously GUI  Integrate GUI with micro controller  Customize buttons on GUI  Manual jog of tester from GUI

Questions? Comments?