Touchpad 3 Click is based on the MTCH6301, a turnkey capacitive touch controller that allows users to quickly and easily integrate projected capacitive touch into their applications from Microchip. The MTCH6301 is characterized by a multitouch function that allows up to 10 pad touches, gesture detection and reporting, single and dual touch drawing, self or mutual signal acquisition, as well as built-in noise detection and filtering. Single finger gestures are a fast and intuitive way to navigate a feature-rich human-machine interface. It supports 11 single finger gestures natively, without requiring interaction from the master processor.

On the front side of the Touchpad 3 Click, there is a clearly defined field that represents a touchpad area. This area is a matrix of conductive electrodes on the PCB, electrically isolated from each other, arranged as rows and columns of X and Y. An electrode consists of multiple diamond-shaped elements, each connected to the next with a conductive neck.

Touchpad 3 Click communicates with MCU using the standard I2C 2-Wire interface that can operate at a maximum speed of 400kbps. The MTCH6301 I2C protocol follows a serial streaming format, not a register-based protocol. For successfully accomplished I2C protocol, the device will assert the active-high INT pin, which is held low during all other activities, whenever a new packet of data is ready to be transmitted to the host. This event can happen under two conditions, when a command has been sent to the controller and when the new touch or gesture data is available, or when the response to this command is ready.

The INT pin, as mentioned before, routed on the INT pin of the mikroBUS™ socket, is utilized by MTCH6301 to signal when the data is available and that the master controller should invoke a master read. Alongside this feature, this Click board™ also has a Reset function routed on the RST pin of the mikroBUS™ socket that will reset the MTCH6301 by driving the RST pin low. When released, the device will assert the INT pin until it has finished initialization routines. For ease of use, the MTCH6301 has the recommended Start-Up sequence that can also be found in the example code that Mikroe offers to its users.

NOTE: Initiating a read from the device when INT is in a low logic state will result in an unpredictable response. Also, if the device is not read within 25ms of asserting the INT pin, a timeout will occur, and data will no longer be available.

This Click board™ is designed to be operated only with a 3.3V logic voltage level. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with different logic levels. However, the Click board™ comes equipped with a library that contains easy to use functions and an example code that can be used as a reference for further development.