1.7.2 Data Structures
qtm_surface_cs_control_t
- Top-level container for surface configuration
- Contains pointers to data and configuration structures
| Struct | Contents |
|---|---|
| qtm_surface_cs_control_t | qtm_surface_contact_data_t *qtm_surface_contact_data; |
| qtm_surface_cs_config_t *qtm_surface_cs_config; |
qtm_surface_contact_data_t
- Run-time data for touch surface
| Parameter | Size | Range/Options | Usage |
|---|---|---|---|
| qt_surface_status | 1 byte | Bit field Bit 7: Reburst required |
Reburst Required = 1 Indicates that further measurements are required to resolve/update contact status. |
| Bit 6: — | — | ||
| Bit 5: POS_V_DEC | Vertical position decreased | ||
| Bit 4: POS_V_INC | Vertical position increased | ||
| Bit 3: POS_H_DEC | Horizontal position decreased | ||
| Bit 2: POS_H_INC | Horizontal position increased | ||
| Bit 1: POS_CHANGE | Change in reported position | ||
| Bit 0: Touch detection | Touch Detection = 1 Indicates that a touch contact is present on the surface |
||
| h_position_abs | 2 bytes | 0 to 4095 | Apparent horizontal position |
| h_position | 2 bytes | 0 to 4095 | Motion filtered horizontal position |
| v_position_abs | 2 bytes | 0 to 4095 | Apparent vertical position |
| v_position | 2 bytes | 0 to 4095 | Motion filtered vertical position |
| contact_size | 2 bytes | — | Sum of touch deltas at contact location |
qtm_surface_cs_config_t
- Configuration parameters for the touch surface
| Parameter | Size | Range/Options | Usage |
|---|---|---|---|
| start_key_h | 2 bytes | 0 to 65534 | Start key of horizontal axis |
| number_of_keys_h | 1 byte | 0 to 255 | The number of keys forming horizontal axis |
| start_key_v | 2 bytes | 0 to 65534 | Start key of vertical axis |
| number_of_keys_v | 1 byte | 0 to 255 | The number of keys forming vertical axis |
| resol_deadband | 1 byte | Bits 7:4 = Resolution 2 to 12 bits | Full-scale position resolution reported for the axis |
| position_hysteresis | 1 byte | 0 to 255 | The minimum travel distance to be reported after contact or direction change. Applies to Horizontal and Vertical. |
| position_filter | 1 byte | Bits7:5: — | — |
| Bit 4: Median Filter | Median filter enable | ||
| Bit3 : — | — | ||
| Bit 2: — | — | ||
| Bits 1:0: IIR Config | IIR Config 0 = None 1 = 25% 2 = 50% 3 = 75% |
||
| contact_min_threshold | 2 bytes | 0 to 65535 | The minimum contact size measurement for persistent contact tracking. Contact size is the sum of neighboring keys’ touch deltas forming the touch contact. |
| *qtm_touch_key_data | Pointer 2/4 bytes |
qtm_touch_key_data_t | Pointer to touch key data for the underlying set of touch keys. |