maxTouch Extractor

Fast capacitance extraction platform for touch screens. A huge part of my work for Atmel Corp.

Transcript

1. Research experience
   Oleg Żero
   Investigation of edge-effects.
   Developing fast
   capacitance-extraction
   platform for touch-screen
   applications.
   CTO technology group
   Atmel Corporation.
   

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2. A part of Atmel’s portfolio was QTouch – touch detection platform
   using a microcontroller unit.
   All hardware and software was in place, however,
   too little was understood about the underlying physics!
   One year as application engineer
   Oleg Żero
   I was getting started again.
   +5V
   local (PCB) ground
   C0
   Human – Earth
   coupling
   Touch – intended
   coupling
   Circuit – Earth
   coupling
   (grounding)
   Human coupling to
   local ground
   (unintended)
   DC picture
   That was opportunity!
   

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3. One year as application engineer
   Oleg Żero
   I was doing ”undercover” research.
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   sensitivity S[%]
   ’squareness’ parameter p [a.u.]
   Influence of the electrode’s shape on sensitivity
   Fill factor relative to 1 cm2 area footprint – FF [%]
   

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4. Building maxTouch Extractor
   Oleg Żero
   It turned out the whole corporation has a problem...
   Drawing
   each time a new
   pattern is drawn
   Solving time
   Drastic scaling with model
   size.
   From ~1.5 h to 1 week on
   large problems.
   Setting up
   required to update
   every boundary
   coondition, assign
   the parameters...
   Pre-processing
   Manual work
   Resources
   Using 48 CPUs on LSF not
   uncommon.
   Computation
   Data collection
   Large amount of data to
   handle. Formulating plots,
   graphs and reports takes
   time.
   Data analysis
   No inspection of physical
   qunatities such as electric
   fields or potential.
   Could they give us some
   hints?
   License cost
   Puts further limits on
   concurrent users.
   Post-processing
   Manual work
   1-2 days
   5-8 h
   ~1 day
   

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5. Building maxTouch Extractor
   Oleg Żero
   And I began to be the solution provider.
   I created a quick extraction platrom for anyone to use.
   

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6. Building maxTouch Extractor
   Oleg Żero
   It demonstrated to be useful.
   I created a quick extraction platrom for anyone to use.
   APP Server
   APP
   APP
   model
   LSF
   1 license per seat
   up to 4 apps per seat
   1 license –
   unlimited
   CPUs
   new app / update
   1 full FNL
   Deployment scheme:
   APP Client
   Standard FNL NOK 169 900 GBP 13 761
   AC/DC Module NOK 89 900 GBP 7 281
   LiveLink to MATLAB NOK 35 900 GBP 2 908
   Standard (FNL): NOK 259 980 GBP 21 059
   Application: NOK 25 980 GBP 2 106
   unit license list price per year:
   

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7. Building maxTouch Extractor
   Oleg Żero
   We started observing new patterns and behaviours.
   Stylus-X:
   A B Γ Δ A
   A B Γ Δ A
   Stylus-Y:
   A B Γ Δ A
   A B Γ Δ A
   A
   Γ
   Δ
   We can observe shift in sensitivity peak
   (edge-to-edge interaction).
   needle stylus
   needle stylus
   needle
   stylus
   Shaft Diam. 0.1 mm 3 mm
   Tip Diam. 0.05 mm 2.5 mm
   Tip Angle
   Z distance
   45 deg
   0.05 mm
   45 deg
   0.05 mm
   needle stylus
   X1
   Y1
   A
   B Γ
   Δ
   

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8. Building maxTouch Extractor
   Oleg Żero
   Got my colleagues to conduct experiments together.
   Sample
   (Stig Larssen)
   Measurements
   (Steinar Myren)
   Model
   275
   150
   150
   4455
   4455
   X-line
   Y-line
   

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9. Building maxTouch Extractor
   Oleg Żero
   Got my colleagues to conduct experiments together.
   4x4 – pattern using all approximations
   Practically no degradation to the results!
   All lines overlap.
   Self-Cap measurement and extraction comparison Self-Cap measurement and extraction comparison
   

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