ATAVRTS2080A Atmel, ATAVRTS2080A Datasheet - Page 116

• Manufacturer Part Number: ATAVRTS2080A
• Description: KIT QTOUCH W/SW ATMEGA88
• Manufacturer: Atmel
• Series: QTouch™r

Specifications of ATAVRTS2080A

• Sensor Type: Touch, Capacitive
• Sensing Range: 1 Rotor, 1 Slider, and 2 Buttons/Keys
• Interface: Application Programming Interface (API)
• Voltage - Supply: 1.8 V ~ 5.5 V
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATmega88
• Tool Type: Development Kit
• Cpu Core: AVR 8 / 32
• Data Bus Width: 8 bit
• Core Architecture: AVR
• Silicon Manufacturer: Atmel
• Silicon Core Number: ATmega88, ATmega88A
• Silicon Family Name: AVR
• Kit Contents: Board, CD
• Development Tool Type: Hardware / Software - Eval/Demo Board
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Lead Free Status / Rohs Status: Details

The burst length values of each Touch channel must be specified using the qm_burst_length[]
array in the main.c file. The burst length must be specified in the same order of Touch Channel
numbering.
The touch_qm_sensors_init API initializes the QTouch Library as well as the CAT module and
does the QMatrix method specific pin, register and Global Sensor configuration.
The
touch_qm_sensor_config API is used to configure individual sensor.
The Sensor specific
configuration parameter can be provided as input to this API.
The touch_qm_sensors_calibrate API is used to calibrate all the configured sensors thereby
preparing the sensors for acquisition. The touch_qm_sensors_start_acquisition API initiates a
QMatrix method measurement on all the configured Sensors. 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 this data. (For an overview of Filter callback
usage, refer
Section 5.6.6.4
Example code). Once 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.
Note 1: The Host Application code can execute once a QMatrix acquisition is initiated with the
touch_qm_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_qm_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.
Note 2: Once the Touch Library has been initialized for QMatrix method using the
touch_qm_sensors_init API, a new qm_burst_length[x] value of a Touch channel must be
updated only using the touch_qm_channel_update_burstlen API. It is recommended to have
qm_burst_length array as global variable as the Touch Library updates this array when the
touch_qm_channel_update_burstlen API is called.
Note 3: QMatrix burst length setting recommendation.
For a given X Line, the burst length value of ALL enabled Y Lines MUST be the same or set to
0x01(disabled). For example, the burst length value corresponding to (X0,Y1),(X0,Y2)...(X0,Yn)
must be the same. In case of a scenario, wherein it is required to have a different a burst length,
then the following option can be tried out - Enable the 1k ohm drive resistors on all the enabled Y
lines by setting the corresponding bit in the CSARES register.
Note 4: For QMatrix operation, the Analog comparators channels are used (using the ACIFB
interface) depending on the Y Lines enabled. For example, when Y lines Y2 and Y7 are enabled
the Analog comparator channels 2 and 7 are used by the CAT module for QMatrix operation.
The user can uses the rest of the Analog comparator channels in the main application. The
QTouch Library enables the ACIFB using the Control register (if not already enabled by the main
application) when the touch_qm_sensors_init API is called.
116
8207J-AT42-02/11