touchpad

Component: touchpad

• This component defines a touchpad as a well encapsulated object.

  • Based on touchpad driver in esp-idf

• A touchpad device is defined by:

  • touchpad number (refer to comments of touch_pad_t for touchpad number and gpio number pair)
  • sensitivity which defines the sensitivity of touchpad (range from 0 to 1.0)

• A touchpad device can provide:

  • iot_tp_add_cb to add callback functions to three different events
  • iot_tp_set_serial_trigger to make touchpad trigger events continuesly while pressing
  • iot_tp_add_custom_cb to add callback function to a custom press duration
  • iot_tp_read to get the sample value of touchpad
  • iot_tp_num_get to get the touchpad number of the touchpad device
  • iot_tp_set_threshold to set the threshold value of the touchpad

• To use the touchpad device, you need to:

  • create a touchpad object return by iot_tp_create()
  • To delete the device, you can call iot_tp_delete to delete the object and free the memory

• More than one touchpad can make up a touchpad slide:

  • call iot_tp_slide_create to get a touchpad slide object
  • call iot_tp_slide_position to get relative position of your touch on slide

• If plenty of touchpads are needed, you can use tp_matrix device:

  • call iot_tp_matrix_create to get a touchpad matrix object
  • m+n touchpad sensors are required to create a touchpad matrix which can provide m*n touchpads
  • many functions of touchpad matrix device are similar with regular touchpad device

• Proximity sensor device is provided to catch a hand proximity:

  • create a proximity sensor device by proximity_sensor_create()
  • call proximity_sensor_add_cb to set the callback function of proximity sensor and callback function will be called if proximity status changes (refer to enum proximity_status_t)
  • call proximity_sensor_read to get the proximity of your hand to sensor, the closer your hand approaches sensor, the larger this value is

• Gesture sensor device is provided to recognize different gestures above sensor:

  • create a gesture sensor by gesture_sensor_create()
  • call gesture_sensor_add_cb to set the callback function of gesture sensor and callback function will be called if any type of gesture is recognized (refer to enum gesture_type_t)

• TouchSensor tune tool ESP-Tuning Tool.

  • ESP-Tuning Tool EN 中文
  • Monitor the data of each touch channel
  • Determine the threshold for each channel
  • Evaluate the performance of touch sensors, including sensitivity, SNR, stability, channel coupling and etc.
  • "ESP-Tuning Tool" can be downloaded from Espressif's official website

NOTE:

• For hardware and firmware design guidelines on ESP32 touch sensor system, please refer to Touch Sensor Application Note, where you may find comprehensive information on how to design and implement touch sensing applications, such as linear slider, wheel slider, matrix buttons and spring buttons.
• Don't delete the same tp_handle more than once and you'd better set the handle to NULL after calling iot_tp_delete()