14.3.1 Data Structures
qtm_gestures_2d_control_t
The qtm_gestures_2d_control_t data interface is a container structure which controls the input and output of this module.
| Field | Unit | Range/Options | Parameter |
|---|---|---|---|
| qtm_gestures_2d_data | qtm_gestures_2d_data _t* | Pointer | Pointer to the gestures data structure |
| qtm_gestures_2d_config | qtm_gestures_2d_config _t* | Pointer | Pointer to the gestures config structure |
qtm_gestures_2d_config _t
The qtm_gestures_2d_config _t data structure is the configuration structure passed to the module.
| Field | Unit | Range/Options | Parameter |
|---|---|---|---|
| horiz_position0 | uint16_t | Pointer | Pointer to the horizontal contact 0 position |
| vertical_position0 | uint16_t | Pointer | Pointer to the vertical contact 0 position |
| surface_status0 | uint8_t | Pointer | Pointer to the status of contact 0 |
| horiz_position1 | uint16_t | Pointer | Pointer to the horizontal contact 1 position |
| vertical_position1 | uint16_t | Pointer | Pointer to the vertical contact 1 position |
| surface_status1 | uint8_t | Pointer | Pointer to the status of contact 1 |
| surface_resolution | uint8_t | 0 to 255 | This parameter defines the resolution of surface |
| tapReleaseTimeout | uint8_t | 0 to 255 | This parameter limits the amount of time allowed
between the initial finger press and the liftoff. Exceeding this
value will cause the firmware to not consider the gesture as a tap
gesture. Note: This
value should be lesser than tapHoldTimeout and swipeTimeout |
| tapHoldTimeout | uint8_t | 0 to 255 |
If a finger stays within the bounds set by TAP_AREA and is not removed, the
firmware will report a Tap Hold gesture once the gesture timer
exceeds this value.
Note: This should
be greater than the tapReleaseTimeout and swipeTimeout |
| swipeTimeout | uint8_t | 0 to 255 |
This value limits the amount of time allowed for the
swipe gesture (initial finger press, moving in a particular
direction, crossing the distance threshold and the
liftoff).
Note: This should
be greater than the tapReleaseTimeout and lesser than tapHoldTimeout |
| xSwipeDistanceThreshold | uint8_t | 0 to 255 | This controls the distance traveled in the X-axis direction for detecting Left and Right Swipe gestures. |
| ySwipeDistanceThreshold | uint8_t | 0 to 255 | This controls the distance traveled in the Y-axis direction for detecting Up and Down Swipe gestures |
| edgeSwipeDistanceThreshold | uint8_t | 0 to 255 | This controls the distance traveled for Edge Swipe gestures |
| tapDistanceThreshold | uint8_t | 0 to 255 | This parameter bounds the finger to an area it must stay within to be considered a Tap gesture when the finger is removed and Tap and Hold gesture if the finger is not removed for some time |
| seqTapDistanceThreshold | uint8_t | 0 to 255 | This parameter limits the allowable distance of the
current touch’s initial press from the liftoff position of the
previous touch. It is used for multiple taps (double-tap,
triple-tap, etc.). If the taps following the first are within this threshold, then the tap counter will be incremented. If the following tap gestures exceed this threshold, the previous touch is sent as a single tap, and the current touch will reset the tap counter. |
| edgeBoundary | uint8_t | 0 to 255 | The firmware can also be modified to define an edge region along the border of the touch sensor. With this defined, Swipe gestures that start in an edge region will be reported as Edge Swipe gestures in place of normal Swipe gestures. |
| wheelPostscaler | int8_t | -128 to 127 | This parameter adjusts the rate at which the Wheel gesture is updated in the GUI |
| wheelStartQuadrantCount | int8_t | -128 to 127 | The Wheel gesture movement can be broken down into
90° arcs. The firmware watches for a certain number of arcs to occur
in a circular pattern before starting to report Wheel gesture
information. The number of arcs that must be first detected is
determined by this parameter. Lower values for this parameter make it faster to start a wheel gesture, but it also makes the firmware prone to prematurely reporting wheel gesture information. |
| wheelReverseQuadrantCount | int8_t | -128 to 127 | This parameter functions like wheelStartQuadrantCount, except it is used when changing the direction of the wheel instead of starting it new. This is used to prevent quick toggling between directions. |
| pinchZoomThreshold | uint8_t | 0 to 255 | This parameter limits the allowable distance between the two fingers to detect the pinch and the zoom gestures. After crossing this parameter value, if the distance between the contacts is reducing, then the gesture is reported as “PINCH”. After crossing this parameter value, if the distance between the contacts is increasing, then the gesture is reported as “ZOOM”. |
qtm_gestures_2d_data_t
The qtm_gestures_2d_data_t data structure is used internally within the module to identify the gesture and to store the status and information.
| Field | Unit | Range/Options | Parameter |
|---|---|---|---|
| gestures_status | uint8_t | 0 or 1 | This indicates if a gesture has been decoded or not |
| gestures_which_gesture | uint8_t | 0 to 255 | This contains the current, decoded gesture |
| gestures_info | uint8_t | 0 to 255 |
This contains the additional gesture information |