ATAVRQTOUCHX Atmel, ATAVRQTOUCHX Datasheet - Page 26

• 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

Fields
qt_burst_lengths[]
The signal gain for each sensor is controlled by circuit parameters as well as the burst length.
The burst length is simply the number of times the charge-transfer (‘QT’) process is performed on
a given sensor. Each QT process is simply the pulsing of an X line once, with a corresponding Y
line enabled to capture the resulting charge passed through the sensor’s capacitance Cx.
The QMatrix acquisition method library exports a variable of this type which can be accessed to
set the burst length for each of the QMatrix channels
extern uint8_t qt_burst_lengths[QT_NUM_CHANNELS];
5.6.4.5
Structure
Input / Output
Use
Fields
State
general_counter
ndil_counter
Threshold
type_aks_pos_hyst
from_channel
to_channel
Index
5.6.4.6
Structure
Input / Output
Use
qt_lib_siginfo_t structure definition for a QTouch acquisition method library variant
Fields
library_version
26
tag_sensor_t
qt_lib_siginfo_t
This data structure is used to specify the burst lengths for each of the QMatrix
channels
tag_sensor_t
Output from the library
Data structure which holds the internal sensor state variables used by the
library.
qt_lib_siginfo_t
Output from the library
Data structure which holds the information about the library variant and its
version information.
Type
uint16_t
Type
uint8_t
Type
uint8_t
uint8_t
uint8_t
uint8_t
uint8_t
uint8_t
uint8_t
uint8_t
Comment
The burst length for each of the QMatrix channel in units of pulses. Default
value: 64 pulses.
These values can be configured for each channel individually.
Comment
Holds the library version information.
Bit fields
Comment
internal sensor state
general purpose counter: used for calibration, drifting, etc
drift Integration counter
sensor detection threshold. Refer to section
details
holds information for sensor type, AKS group, positive recalibration flag, and
hysteresis value
Bit fields
B1 : B0
B2
B5:B3
B7:B6
starting channel number for sensor
ending channel number for sensor
index for array of rotor/slider values
Use
Hysteresis. Refer to section
details
positive recalibration flag
AKS group. Refer to section 5.4.5 for more details
sensor type
Use
5.4.1 Detect threshold
5.4.2 Hysteresis
8207J-AT42-02/11
for more
for more