Resources used by QMatrix acquisition method libraries

The following additional resources are used by the QMatrix acquisition method libraries.

1. 1.

   One Analog Comparator

2. 2.

   One internal Timer ( Usually Timer1 depending on the availability on particular microcontroller)

3. 3.

   One ADC Multiplexer( The critical section of the touch sensing library disables the use of ADC as conversion unit and enables the same ADC as a multiplexer, but the user can use the ADC for conversion in rest of his application  code )

4. 4.

   The ADCMUX is used by the library during the touch sensing acquisition, however it is restored with the value from host application before exiting the qt_measure_sensors() such that the ADC is available to the host application for conversion.

In case of XMega devices, the resources are used internal to the library and hence cannot be used by the host application

1. 1.

   Analog Comparator0 on PORTA (AC0 on PORTA)

2. 2.

   Timer/Counter1 on PORTC (TCC1)

3. 3.

   Event System Channel0 (EVSYS_CH0)