Intermediate
30 min

Accurately detect and analyze colors with VEML6040 and STM32F031K6

Color excellence at your fingertips

Color 4 Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

Color 4 Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Improve efficiency and accuracy in color-related tasks, from design and manufacturing to diagnostics and beyond.

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Hardware Overview

How does it work?

Color 4 Click is based on the VEML6040, an advanced RGB/ambient light sensor from Vishay Semiconductors that provides fast and accurate spectral measurements. It is based on the Filtron™ technology, achieving the closest ambient light spectral sensitivity to real-human eye responses. The VEML6040 senses red, green, blue, and white light and processes those signals using a CMOS signal conditioning circuit. This digital RGBW information can be used in feedback control systems, among other things, to monitor and actively control a light source. This Click board™ detects light intensity under multiple lighting

conditions and through different attenuation materials, including dark glass. The VEML6040 provides a selectable measurement range from 515.4lx up to 16.496lx with the highest sensitivity of 0.007865lx/step. Its peak sensitivities for red, green, and blue are 645nm, 575nm, and 460nm, respectively. Moreover, it provides excellent temperature compensation, keeping the output stable under changing temperatures. Color 4 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting Standard Mode operation with a clock frequency of 100kHz and Fast Mode

up to 400kHz. The VEML6040 contains one configuration register (00h) for operation control and parameter setup. Its measurement results are stored in four separate registers, each for red, green, blue, and white, with addresses from 08h to 0Bh, respectively. All registers are 16-bit wide. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Color 4 Click top side image
Color 4 Click bottom side image

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB6
SCL
I2C Data
PB7
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Color 4 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
2x4 RGB Click front image hardware assembly
Prog-cut hardware assembly
Nucleo-32 with STM32 MCU MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for Color 4 Click driver.

Key functions:

  • color4_set_config - Color 4 set configuration function

  • color4_get_color_data - Color 4 get color data function

  • color4_get_ambient_light - Color 4 get ambient light level function

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * @file main.c
 * @brief Color 4 Click example
 *
 * # Description
 * This library contains API for the Color 4 Click driver.
 * This driver provides the functions for the sensor configuration
 * and for reading RGBW and ambient light data from the device.
 * This example displays RGBW data, Ambient light level, CCT data 
 * and the light color names.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of I2C module and log UART.
 * After driver initialization, default settings turn on the device.
 *
 * ## Application Task
 * This example demonstrates the use of the Color 4 Click board™.
 * Reads and displays the results of the RGBW, Ambient light level, 
 * calculate the correlated color temperature. 
 * This example also detects and displays the light color names.
 * Results are being sent to the UART Terminal, where you can track their changes.
 *
 * @note
 * Color detection is obtained based on the analysis 
 * of calculate the correlated color temperature (CCT) data
 * and the CIE 1931 chromaticity diagram.
 * For more details please refer to the “Designing the VEML6040 into an Application” 
 * application note (www.vishay.com/doc?84331).
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "color4.h"

#define COLOR4_LIM_WHITE_COLOR        17000
#define COLOR4_LIM_DARK_LUX           15.0
#define COLOR4_CCT_LIM_BLUE_COLOR     9000
#define COLOR4_CCT_LIM_PURPLE_COLOR   7500
#define COLOR4_CCT_LIM_GREEN_COLOR    6000
#define COLOR4_CCT_LIM_YELLOW_COLOR   3500
#define COLOR4_CCT_LIM_ORANGE_COLOR   2200
#define COLOR4_CCT_LIM_PINK_COLOR     1900
#define COLOR4_CCT_LIM_RED_COLOR      700

static color4_t color4;
static log_t logger;
static uint16_t red_data, green_data, blue_data, white_data;
static float ambient_light, cct;

void display_color ( void )
{
    if ( ambient_light < COLOR4_LIM_DARK_LUX )
    {
        log_printf( &logger, " Color DARK\r\n", cct );
    }
    else if ( white_data > COLOR4_LIM_WHITE_COLOR )
    {
        log_printf( &logger, " Color WHITE\r\n", cct );   
    }
    else if ( cct > COLOR4_CCT_LIM_BLUE_COLOR  )
    {
        log_printf( &logger, " Color BLUE\r\n", cct );
    }
    else if ( cct > COLOR4_CCT_LIM_PURPLE_COLOR )
    {
        log_printf( &logger, " Color PURPLE\r\n", cct );
    }
    else if ( cct > COLOR4_CCT_LIM_GREEN_COLOR )
    {
        log_printf( &logger, " Color GREEN\r\n", cct );
    }
    else if ( cct > COLOR4_CCT_LIM_YELLOW_COLOR )
    {
        log_printf( &logger, " Color YELLOW\r\n", cct );
    }
    else if ( cct > COLOR4_CCT_LIM_ORANGE_COLOR )
    {
        log_printf( &logger, " Color ORANGE\r\n", cct );
    }
    else if ( cct > COLOR4_CCT_LIM_PINK_COLOR )
    {
        log_printf( &logger, " Color PINK\r\n", cct );
    }
    else if ( cct > COLOR4_CCT_LIM_RED_COLOR )
    {
        log_printf( &logger, " Color RED\r\n", cct );
    }
    else
    {
        log_printf( &logger, " Color BLUE\r\n", cct );
    }
}

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    color4_cfg_t color4_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.
    color4_cfg_setup( &color4_cfg );
    COLOR4_MAP_MIKROBUS( color4_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == color4_init( &color4, &color4_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( COLOR4_ERROR == color4_default_cfg ( &color4 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
    log_printf( &logger, " ----------------------\r\n" );
    Delay_ms( 100 );
}

void application_task ( void ) 
{
    if ( COLOR4_OK == color4_get_color_data( &color4, COLOR4_RED, &red_data ) )
    {
        log_printf( &logger, " Red: %u\r\n", red_data );
    }

    if ( COLOR4_OK == color4_get_color_data( &color4, COLOR4_GREEN, &green_data ) )
    {
        log_printf( &logger, " Green: %u\r\n", green_data );
    }

    if ( COLOR4_OK == color4_get_color_data( &color4, COLOR4_BLUE, &blue_data ) )
    {
        log_printf( &logger, " Blue: %u\r\n", blue_data );
    }

    if ( COLOR4_OK == color4_get_color_data( &color4, COLOR4_WHITE, &white_data ) )
    {
        log_printf( &logger, " White: %u\r\n", white_data );
    }
    log_printf( &logger, " - - - - - - -  - - - - \r\n" );

    if ( COLOR4_OK == color4_get_ambient_light( &color4, &ambient_light ) )
    {
        log_printf( &logger, " ALS lux level: %.2f\r\n", ambient_light );
    }

    if ( COLOR4_OK == color4_get_cct( &color4, &cct ) )
    {
        log_printf( &logger, " CCT: %.2f\r\n", cct );
    }
    log_printf( &logger, " - - - - - - -  - - - - \r\n" );

    display_color( );
    log_printf( &logger, " ----------------------\r\n" );
    Delay_ms( 1000 );
}

void main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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