Proximity 10 Click Board

With its high sensitivity and signal to noise ratio, the Proximity 10 Click Board™ is ideally suited for a range of applications that rely on accurate and reliable proximity detection. It can be used for proximity activated surveillance systems, equipment lid closing, object proximity detection, simple gesture activated HID interface, and other similar applications which rely on an accurate object proximity detection.

How Does The Proximity 10 Click Board™ Work?

The main sensor IC on the Proximity 10 Click Board™ is the SI1143, a photometric sensor for the ambient light and proximity detection, from Silicon Labs. Among other sections, this IC contains a LED driver, used to drive an externally connected LED, which provides feedback for the SI1143 sensory sections. Therefore, the LED should be chosen so that its spectrum matches the spectral sensitivity of the on-chip light sensor. For this reason, the Click board™ is equipped with the narrow beam LED from Rohm Semiconductor with its spectral response characteristic peaking at 870nm, which is a perfect choice for this application.

The proximity detection consists of sending a pulse to the LED while measuring the response of the reflected light. Most of the parameters are user configurable, such as the sampling frequency, pulses duration, averaging parameters and more. More in-depth information about the registers can be found in the SI1143 datasheet. Aimed towards the low consumption market, the SI1143 uses a rather low voltage range, between 1.7V and 3.6V. Since the most of the MCUs use 3.3V, the Proximity 10 Click Board™ is designed so that the SI1143 IC is directly interfaced with the mikroBUS™.

The Proximity 10 Click Board™ offers an interrupt output pin that can be used to trigger an interrupt on the host MCU. The SI1143 IC interrupt engine allows several interrupt sources, which can be used to trigger a state change on the INT pin. These sources include proximity detection interrupts (proximity OFF and proximity ON), sample interrupts, and more. The INT pin itself is highly configurable, and when asserted, this pin triggers an MCU interrupt, informing it that the configured interrupt event has occurred. The MCU can then read the desired register output, not having to poll it constantly, which saves both MCU cycles and power. The INT pin is routed via the level shifting IC to the mikroBUS™ INT pin.

As already mentioned, detailed information on the SI1143 IC registers can be found in the datasheet. However, MikroElektronika provides a library that contains functions compatible with the MikroElektronika compilers, which can be used for simplified programming of the Proximity 10 click. The library also contains an example application, which demonstrates its use. This example application can be used as a reference for custom designs.

Specifications

Pinout Diagram

This table shows how the pinout on the Proximity 10 Click Board™ 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	NC
NC	2	RST	INT	15	INT	Interrupt output
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