ATAVRQTOUCHX Atmel, ATAVRQTOUCHX Datasheet - Page 121

• Manufacturer Part Number: ATAVRQTOUCHX
• Description: BOARD EVAL CAPACITIVE TOUCH
• Manufacturer: Atmel
• Series: QTouch™r

Specifications of ATAVRQTOUCHX

• Sensor Type: Touch, Capacitive
• Sensing Range: 1 Slider, 1 Wheel, 2 Buttons
• Interface: USB
• Voltage - Supply: 5V, USB
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: AT90USB1287, ATxmega128A1
• Silicon Manufacturer: Atmel
• Silicon Family Name: ATxmega
• Kit Contents: Board
• Svhc: No SVHC (15-Dec-2010)
• Core Architecture: AVR
• Core Sub-architecture: AVR19
• Kit Features: One Slider, One Wheel And 2
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

6.3.8.5
QTouch Group A/B method API Flow for UC3L
For the QTouch operation, the CAT_CLK must be setup appropriately as a first step. Depending
on QTouch Group that need to be used, the QTouch Group A, QTouch Group B and Common
configuration parameters in the touch_config_at32uc3l.h configuration must then be set up.
The first input argument to the QTouch API, TOUCH_QT_GRP_A or TOUCH_QT_GRP_B
indicates if the QTouch API must perform the necessary operation on Group A Sensors or Group
B Sensors. The touch_qt_sensors_init API initializes the QTouch Library as well as the CAT
module and does the QTouch method specific pin, register and Global Sensor configuration. The
touch_qt_sensor_config API is used to configure individual sensor.
The Sensor specific
configuration parameter can be provided as input to this API.
The touch_qt_sensors_calibrate API is used to calibrate all the configured sensors thereby
preparing the sensors for acquisition. The touch_qt_sensors_start_acquisition API initiates a
QTouch method measurement on all the configured Sensors (corresponding to the input Touch
Group A or B). This API takes the peripheral DMA channels as an input. When a filter_callback
function is enabled, the touch_event_dispatcher function calls the filter_callback function as soon
as the raw acquisition data from the Sensors is available. The user can now optionally apply any
filtering routine on the raw acquisition data before the QTouch Library does any processing on
Example code). Once
this data. (For an overview of Filter callback usage, refer
Section 5.6.6.4
the QTouch Library has finished processing the acquisition data from Sensors, the
touch_event_dispatcher function calls the measure_complete_callback function indicating the end
of a single Touch measurement operation.
The measure_complete_callback provides the
measured data and Touch status information. The measured data is available in the same order
of Touch Channel numbering. Separate Filter and Measure complete callback functions must be
provided for Group A and Group B Sensors.
Note: The Host Application code can execute once a QTouch acquisition is initiated with the
touch_qt_sensors_start_acqusition API. Care must be taken in the Host Application such that the
touch_event_dispatcher function is called frequently in order to process the acquired data. For a
single Touch measurement operation (between a touch_qt_sensors_start_acquisition API call
and the measure_complete_callback function being called), the touch_event_dispatcher function
may execute multiple times in order to resolve the Touch status of Sensors. Failing to call the
touch_event_dispatcher frequently can adversely impact the Touch Sensitivity.
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