ATQT600 Atmel, ATQT600 Datasheet - Page 60

• Manufacturer Part Number: ATQT600
• Description: KIT EVAL TOUCH FOR QT600
• Manufacturer: Atmel
• Series: QTouch™r

Specifications of ATQT600

• Sensor Type: Touch Screen
• Interface: USB
• Embedded: Yes, Other
• Utilized Ic / Part: ATtiny88, ATmega324PA, ATxmega128A1
• Processor To Be Evaluated: ATtiny88, ATmega324, ATxmega128
• Data Bus Width: 8 bit, 16 bit
• Interface Type: USB
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 1.6 V to 3.6 V
• Silicon Manufacturer: Atmel
• Kit Application Type: Sensor
• Application Sub Type: Touch Sensor
• Kit Contents: USB Bridge, MCU Cards, Touchpad Cards
• Svhc: No SVHC (15-Dec-2010)
• Mcu Supported Families: ATtiny88,
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Sensitivity: -
• Sensing Range: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

5.6.10.3.3 Checklist of items for integrating QMatrix Capacitive sensing libraries
When integrating QMatrix acquisition method libraries, ensure the following
5.6.10.4 Common checklist items
5.6.10.4.1 Configuring the stack size for the application
The stack requirements for the QTouch library should be accounted for and the stack size
adjusted in the user’s project for proper operation of the software when using the IAR IDE. This
section lists the stack usage for the different variants of the QTouch and QMatrix acquisition
method libraries applicable to the IAR compiler tool chain.
Note: When using the IAR IDE / compiler tool chain, the map file generated for the application will
list total CSTACK & RSTACK requirements. Please adjust the total CSTACK and RSTACK
values in the IAR project options to be greater than the values listed in the map file. Refer to
section 5.6.11.4 which illustrates how to change the settings in IAR IDE.
Table 5 : Stack requirements of the QTouch capacitive sensing libraries when using IAR IDE
projects
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In case of XMega devices, the resources are used internal to the library and hence cannot be
used by the host application
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Check that the CLKPR register is available for the selected device. If not remove the
CLKPR statements.
Ensure that the configuration for the QMatrix is done in touch_qm_config.h and the
arrays of the x_line_info and y_line info are filled as indicated section 5.8.2
MCUCR register is available and if so disable pullups
Check if the timer registers and bit fields used are correct and change them if necessary.
The above settings can be modified by the user by changing the API’s that are available
to the user. The API’s include
The host application must provide the current time.
This information is passed to the library as an argument to the function
qt_measure_sensors()”. This is used for time-based library operations such as drift
compensation.
The GPIO internal pull-ups must be disabled for all port pins used for touch sensing when
calling the library.
For 8-bit AVR devices, this can be done by
Setting the JTD bit in the “MCUCR” register to disable JTAG Interface in MCU ( if
available ). This can be done only when the JTAG lines are in conflict with the desired
touch sensing lines.
The library must be called often enough to provide a reasonable response time to user
touches. The typical time to call the library is from 25 ms to 50 ms.
Care should be taken while using the ADC conversion logic and QMatrix library such that
the host application waits for approximately 1msec before actually calling the
qt_measure_sensors() API depending upon the ADC clock.
o
o
o
o
qt_set_parameters ( )
a. Setting the “PUD” bit in the “MCUCR” register or
b. Setting the “PUD” bit in the “SFIOR” register.
Analog Comparator0 on PORTA (AC0 on PORTA)
Timer/Counter1 on PORTC (TCC1)
Event System Channel0 (EVSYS_CH0)
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