12.4 Operation

The API function ‘qtm_surface_cs_process()’ is called after acquisition and touch key processing.

Making contact:

When contact is made with the surface sensor

  1. The module checks all keys on the surface for touch contact detection.
  2. If a key in detect is found, the position is calculated.
  3. The contact size is calculated and compared against the minimum contact threshold.
  4. The surface goes into the ‘Detect’ condition.

Tracking/Releasing contact:

  1. The module checks all keys for touch contact.
  2. If no key is in detect, the module searches for a pair of neighboring keys whose touch delta exceeds the minimum contact threshold.
  3. If such a contact is found, then the new position is calculated.

    Or

  4. If no such contact is found, the surface returns to ‘No Detect’ condition.