ProxFusion 3 Click Board™

How Does The ProxFusion 3 Click Board™ Work?

The ProxFusion 3 Click Board™ is based on the IQS269A, an eight-channel ProxFusion® capacitive, proximity, and touch controller with additional Hall-effect and inductive sensing, best in class signal-to-noise ratio, and low power consumption from Azoteq. The ProxFusion® module detects the capacitance changed with a charge-transfer method. In effect, the IQS269A represents a low-power microcontroller that features ProxFusion® technology for high-end proximity and touch applications and provides a highly integrated capacitive-touch solution with flexibility, unique combination sensing, and long-term stability. During low power mode, the ProxFusion® module can periodically wake the CPU based on a ProxFusion® timer source. Other features include automatic tuning and differential offset compensation for sense electrodes.

The Click board™ has eight PCB pads used to sense touch or proximity events. These pads are the only elements on the top side of the board, allowing the placement of the protective acrylic plexiglass layer. These pads can be programmed to generate a touch event for both when they are pressed and released. If a touch event is detected on one of the onboard pads, the state of the corresponding channel will be changed, indicating an activated channel, more precisely, touch has been detected on that specific channel.

ProxFusion 3 Click communicates with MCU using a standard two-wire I2C interface that supports Fast Mode with a frequency of up to 400kHz. In addition to these pins, the IQS269A has a ready interrupt line, routed on the INT pin of the mikroBUS™ socket, that indicates a communication window, and one general-purpose pin labelled as GP and routed on the PWM pin of the mikroBUS™ socket. The GP pin represents a custom touch-out/sync-in function with which one can assign a touch flag state of any channel. Besides, also allows the choice of the least significant bit (LSB) of its I2C slave address by positioning the SMD jumper labelled as ADDR SEL to an appropriate position marked as 0 and 1.

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 functions and an example code that can be used, as a reference, for further development.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout on ProxFusion 3 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
NC	1	AN	PWM	16	GP	Touch-Out/Sync-In
NC	2	RST	INT	15	INT	Interrupt
NC	3	CS	RX	14	NC
NC	4	SCK	TX	13	NC
NC	5	MISO	SCL	12	SCL	I2C Clock
NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

ONBOARD SETTINGS AND INDICATORS

PROXFUSION 3 CLICK ELECTRICAL SPECIFICATIONS