The AVR DA family of microcontrollers offers the built-in PTC module, which performs touch data acquisitions on the capacitive touch sensors autonomously without any CPU intervention.
The PTC peripheral supports both self-capacitance and mutual capacitance sensing methods for the button, slider, wheel, and 2D surface sensors. The PTC peripheral, together with Microchip Touch Library, offers an unprecedented degree of combinations for touch interface design.
Depending on the device package type and device configuration, there are up to 46 PTC channels available on an AVR DA microcontroller. 46 PTC channels can be used as up to 46 self-sensing buttons or 529 mutual sensing nodes. For more details on sense channels availability, refer to the device-specific data sheet.
The PTC within the AVR DA family can be utilized by the Microchip Touch Library to deliver a robust touch experience under varying environmental conditions. The SleepWalking feature of the PTC allows it to perform touch sensing autonomously on a single, low-power sensor, with the help of the Event System.
- 1.To access the PTC peripheral and the Microchip Touch Library, Atmel START must be used to configure the PTC and link the library to application software. Use the Atmel START QTouch® Capacitive Sensing Library step-by-step guide for more details.
- 2.The Microchip Touch Library enables the use of buttons, sliders, wheels, proximity sensing, and touch surface in a variety of combinations on a single interface.