ATAVRQTOUCHX Atmel, ATAVRQTOUCHX Datasheet - Page 167

• 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

6.5.4
For the QTouch Libraries, the timing information is provided by the Host Application by updating
the ‘time_current_ms’ variable in the Timer ISR.
calculate the necessary timing for Max ON Duration, Drift and Recalibration functionality. Before
using the QTouch Libraries, the Timer ISR must be configured appropriately. Also, the Timer
Interrupt is used to update the ‘time_to_measure_touch’ variable inorder to start a capacitive
touch measurement.
The touch_config.h configuration header file must be used to set the number of channels and
charge share delay based on the library used. For example, if the library used is a 12 channel
library
CHARGE_SHARE_DELAY must be specified as 2 in the touch_config_dp.h. This information
must be provided irrespective of the number of channels actually used.
The desired number of touch buttons used can be enabled using the qt_enable_key() routine.
The channel numbers are sequential from Port A through Port B. Also, individual sensor
Threshold, Hysteresis, AKS group and Recalibration parameters can be set using this function
call.
accessing the global configuration data structure.
When developing a Host application for ATtiny40 device, ensure that the ADC prescalar is set in
such a way that it is in the range of 50 KHz to 250 KHz. For example, if the main clock is running
at 8MHz then set the ADC prescalar to 32 or more. This must be done to ensure proper touch
sensing acquisition.
The Sensor Global Configuration parameters can also be set by the user by directly
API Flow diagram for ATtiny40
with
2
csd
then
QT_NUM_CHANNELS
The QTouch Library uses this variable to
must
be
specified
as
12
and
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