ATAVRQTOUCHX Atmel, ATAVRQTOUCHX Datasheet - Page 41

• 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

So, the order in which the user enables the sensors is the order in which the sensors are
numbered. Depending on the user requirements, the sensors can be configured in the preferred
order.
NOTE: In case of QMatrix, the channels on the Unused X lines (or) unused Y lines should be
ignored and not to be used as arguments in this API.
Ex: If the host application needs only 24 channels , there are two possible options.
5.6.6.3
The ATMEL QTouch Library API provides a function pointer called “qt_filter_callback”. The user
can use this hook to apply filter functions to the measured signal values.
If the pointer is non-NULL, the library calls the function after library has made capacitive channel
measurements, but before the library has processed the channel information and determining the
sensor states.
Example: Averaging the Last Four Signal Values
1. Add a static variable in the main module:
Filtering Signal Measurements
Figure 5-10 : Block diagram to represent usage of filter callback function
1.
2.
In 32 (8x4 configuration), if X6 and X7 are unused, channel6, channel7,
channel14, channel15, channel 22, channel23, channel30, channel 31
cannot be used
In 32 (8x4 configuration), if Y3 is unused, channe24, channel25,
channel26, channel27, channel 28, channel29, channel30, channel 31
cannot be used
qt_touch_status_rotor_slider_values[]
qt_touch_status.sensor_states[]
QTouch/QMatrix Channel Acquisition Method
optional qt_filter_callback() function
post-processing
modified channel_signals[]
modified channel_signals[]
channel_signals[]
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