PROXIMITY 9 CLICK
PID: MIKROE-3465 Weight: 18 g
Proximity 9 click is a very accurate and reliable proximity sensing (PS) and ambient
light sensing (ALS) device, equipped with the VCNL4040, an integrated PS and ALS
sensor which features the Filtron™ technology. The 940nm IRED emitter, along with the
low noise analog front end, and the PS/ALS photo-sensitive elements, is integrated on
the VCNL4040 IC, ensuring very accurate and reliable measurements. The proprietary
Filtron™ technology provides response near to the human eye spectral response,
providing the background light cancellation. The programmable interrupt engine allows
for the development of an optimized firmware, reducing the MCU workload and power
consumption.
Proximity 9 click is supported by a mikroSDK compliant library, which includes functions
that simplify software development. This Click board™ comes as a fully tested product,
ready to be used on a system equipped with the mikroBUS™ socket.
The VCNL4040 also integrates some additional features for better reliability. It has an
intelligent crosstalk cancelation scheme implemented, in order to reduce the crosstalk
phenomenon. A smart persistence allows the interrupt engine to avoid false interrupt
triggering. Rich with features, this Click board™ can be used for a range of different
applications which rely on the accurate and reliable close proximity and ambient light
sensing, including PC and laptop displays, POS displays, embedded displays,
proximity-activated short-range security, lux meters, etc.
HOW DOES IT WORK?
Proximity 9 click features the VCNL4040, a fully integrated proximity and ambient light
sensor with I2C interface, from Vishay Semiconductors. It is an advanced 16bit Ambient
Light Sensor (ALS) which makes use of the proprietary Filtron™ technology, providing
spectral response near to a human eye. The ALS sensor also helps with the flickering of
fluorescent light sources, and background light cancellation, reducing the workload of
the host MCU. This sensor features a 940 nm IRED on-chip, driven by a programmable
current sink driver. The VCNL4040 is also thermally compensated, allowing very
accurate readings within the range between -40⁰C and +85⁰C.
The Proximity Sensing (PS) section of the VCNL4040 IC implements several solutions
for the improved proximity detection of objects of any color. It relies on the detection of
the reflected IR light from the IRED emitter. Features such as the immunity to a red
glow, intelligent crosstalk phenomenon reduction, smart persistence scheme for false
interrupt triggering prevention, programmable IRED current, selectable sampling
resolution, and selectable integration time, help achieving a reliable and accurate
proximity detection. The processed readings of the ALS and PS sensors can be fetched
from the respective registers via the I2C interface. The I2C bus lines are routed to the
respective mikroBUS™ I2C pins: SCL is the I2C clock and SDA is the I2C data line.
Proximity 9 click offers programmable interrupt engine. The INT pin is routed to the
mikroBUS™ INT pin and it is pulled up by the onboard resistor. When asserted, it is
driven to a LOW logic level. The interrupt can be programmed to be triggered whenever
PS threshold window is exceeded, for a programmed number of times (interrupt
persistence). There are two interrupt modes: the interrupt will remain latched in the
normal mode until the interrupt status flag is read by the host firmware. If set to a logic
mode, the interrupt will be asserted when the PS value rises above the high threshold
level, and de-asserted when the PS value falls below the low threshold level. The logic
mode is useful when an autonomous operation with some external circuit is required,
while the normal mode is best suited to be used with the MCU. The INT pin is routed to
the INT pin of the mikroBUS™.
The Click board™ is supported by the mikroSDK library, which contains functions for
simplified development. The mikroSDK functions are well-documented, but there is still
a need, the datasheet of the VCNL4040 offers a listing of all the registers and their
specific functions.
The Click board™ is designed to work with 3.3V only. When using it with MCUs that use
5V levels for their communication, a proper level translation circuit should be used.
SPECIFICATIONS
Type
Proximity
Applications
This Click board™ can be used for a range of different applications
which rely on the accurate and reliable close proximity and ambient
light sensing, including PC and laptop displays, POS displays,
embedded displays, proximity-activated short-range security, lux
meters, etc.
On-board
modules
VCNL4040, an integrated proximity and ambient light sensor with
I2C interface and interrupt function, by Vishay.
Key Features
A reliable ambient light and proximity sensor IC featuring Filtron™
technology for realistic ambient light detection, immunity to red
glow, crosstalk, and backlight interferences, immunity to light
flickering, etc.
Interface
I2C
Input Voltage
3.3V
Click board
size
M (42.9 x 25.4 mm)
PINOUT DIAGRAM
This table shows how the pinout on Proximity 9 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
NC
NC
2
RST
INT
15
INT
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
Interrupt output
Ground
ONBOARD SETTINGS AND INDICATORS
Label
Name
Default
LD1
PWR
-
Description
Power LED indicator
SOFTWARE SUPPORT
We provide a library for the Proximity 9 click on our LibStock page, as well as a demo
application (example), developed using MikroElektronika compilers. The demo can run
on all the main MikroElektronika development boards.
Library Description
This library allows user to get Proximity output data in the desired resolution and ALS
output data calculated to lux. User also can configure the ALS sensitivity by changing
the ALS integration time. This library also offers a choice to check a desired interrupt
flags to be sure which interrupt is generated. For more details check documentation.
Key functions:
T_PROXIMITY9_RETVAL proximity9_readReg( uint8_t regAddr, uint16_t *dataOut ) - This function
reads a 16bit data from the desired register.
T_PROXIMITY9_RETVAL proximity9_writeReg( uint8_t regAddr, uint16_t dataIn ) - This function
writes a 16bit data to the desired register.
float proximity9_get_ALS_lux( void ) - This function allows user to get the ALS value calculated
to lux.
Examples description
The application is composed of the three sections :
System Initialization - Initializes peripherals and pins.
Application Initialization - Initializes I2C interface and performs a device configurations.
Application Task - (code snippet) - Performs a data reading and interrupt flag checking. Allows data
and interrupt flags messages to be showed on the uart terminal. Note : The ALS sensitivity depends
on the ALS integration time setting. The longer integration time has higher sensitivity. The Proximity
(PS) output data can be set to 12-bit or 16-bit resolution.
void applicationTask()
{
als_data = proximity9_get_ALS_lux();
proximity9_readReg( _PROXIMITY9_PS_DATA_REG, &prox_data );
int_check = proximity9_check_int_flag( _PROXIMITY9_PS_IF_CLOSE_FLAG | _PROXIMITY9_PS_IF_AW
AY_FLAG );
FloatToStr( als_data, text );
mikrobus_logWrite( "** ALS : ", _LOG_TEXT );
mikrobus_logWrite( text, _LOG_TEXT );
mikrobus_logWrite( " lux", _LOG_LINE );
WordToStr( prox_data, text );
mikrobus_logWrite( "** PROXIMITY : ", _LOG_TEXT );
mikrobus_logWrite( text, _LOG_LINE );
if (int_check == _PROXIMITY9_PS_IF_CLOSE_FLAG)
{
mikrobus_logWrite( "** Object is close!", _LOG_LINE );
mikrobus_logWrite( "************************************", _LOG_LINE );
Sound_Play( 1200, 50 );
Delay_ms( 50 );
Sound_Play( 1200, 50 );
Delay_ms( 50 );
Sound_Play( 1200, 50 );
}
if (int_check == _PROXIMITY9_PS_IF_AWAY_FLAG)
{
mikrobus_logWrite( "** Object is away!", _LOG_LINE );
mikrobus_logWrite( "************************************", _LOG_LINE );
Sound_Play( 1100, 100 );
Delay_ms( 50 );
Sound_Play( 1100, 100 );
}
if (int_check == _PROXIMITY9_INT_CLEARED)
{
mikrobus_logWrite( "************************************", _LOG_LINE );
Delay_ms( 200 );
}
}
The full application code, and ready to use projects can be found on our LibStock page.
Other mikroE Libraries used in the example:
I2C
UART
Conversions
Sound
Additional notes and informations
Depending on the development board you are using, you may need USB UART
click, USB UART 2 click or RS232 click to connect to your PC, for development systems
with no UART to USB interface available on the board. The terminal available in all
MikroElektronika compilers, or any other terminal application of your choice, can be
used to read the message.
MIKROSDK
This click board is supported with mikroSDK - MikroElektronika Software Development
Kit. To ensure proper operation of mikroSDK compliant click board demo applications,
mikroSDK should be downloaded from the LibStock and installed for the compiler you
are using.
For more information about mikroSDK, visit the official page.
https://www.mikroe.com/proximity‐9‐click/4‐23‐19