13.1 Overview

This module provides the functionality of a 2D touch surface with two-contact support for touchscreen/ touchpad applications.

  • Touch Contact X and Y Position
  • Up to 32x32 Sensors
    • Limited by maximum compensation capacitance per row/column
  • Mutual or Self-Capacitance
  • Optimized Crossed Sliders Measurements
    • (MxN) sensor array measured in (M+N) acquisitions
  • Persistent Contact Tracking
  • Contact Path Extrapolation
  • Position Filtering
    • IIR
    • Median
    • Hysteresis
    • Dead band

The Surface CS/2T module is intended for use with a grid of sensor keys which are arrayed over the surface area.

The Surface CS/2T module is configured to interface with the QTML touch key module (0x0002) or a compatible touch detection module. Pointers are required to the location of touch key data in a standard format, as defined in the common API file.

Important: The two positions outputted by this 2D Surface (Two-Finger Touch) CS/2T module can be used only for gesture detection. Therefore, it is not advisable to use this module without gesture support.
A minimum of eight sensors in each dimension is recommended to achieve reliable performance with two touch contacts. The use of fewer sensors severely restricts the isolation space for independent contacts.
Table 13-1. Module Files
GCC CompilerE.g., Atmel Studio 7

libqtm_surface_cs2t_xxxxx_0x0025.a

libqtm_surface_cs2t_32x32_xxxxx_0x003c.a

IAR CompilerAVR® devices

qtm_surface_cs2t_xxxxx_0x0025.r90

qtm_surface_cs2t_32x32_xxxxx_0x003c.r90

Arm® devices

qtm_surface_cs2t_xxxxx_0x0025.a

qtm_surface_cs2t_32x32_xxxxx_0x003c.a

Note: “xxxxx” refers to the target processor or architecture.

Module with ID 0x0025: Supports up to a maximum of 16x16.

Module with ID 0x003c: Supports up to a maximum of 32x32.