Beginner
10 min

Achieve precise color detection and customization with ISL29125 and PIC18F27K42 in various applications

Unveiling the spectrum

Color 2 Click with Curiosity HPC

Published Jan 23, 2024

Click board™

Color 2 Click

Dev. board

Curiosity HPC

Compiler

NECTO Studio

MCU

PIC18F27K42

Discover how this innovative RGB color sensing solution opens up a world of possibilities, enabling you to accurately capture and analyze colors for a multitude of applications

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Hardware Overview

How does it work?

Color 2 Click is based on the ISL29125, a low power, high sensitivity, red, green, and blue color light sensor (RGB) with a compatible I2C interface from Renesas. The ISL29125’s state-of-the-art photodiode array provides an accurate RGB spectral response and excellent light source-to-light source variation, designed to reject IR in light sources, allowing the device to operate in environments from sunlight to dark rooms. It detects red, green, and blue in various lighting conditions, outputting high-resolution data in a measuring range from 0.152 lux to 10,000 lux. Both the range and output resolution are selectable through an I2C interface. After light is converted to the current during the light-to-signal process, the current output is converted to a digital count by

an on-chip analog-to-digital converter with an integrating architecture. The ADC converter resolution is selectable from 12 or 16 bits, with its conversion time inversely proportional to the ADC resolution. The ADC also provides two programmable ranges to accommodate different lighting conditions dynamically. For dim conditions, the ADC can be configured at its high sensitivity (low optical) range, while for bright conditions, it can be configured at its low sensitivity (higher optical) range. The ISL29125 also incorporates an IR blocking filter, allowing this Click board™ to operate even under a dark glass cover. This Click board™ communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting a Fast

Mode up to 400kHz. Besides, it also possesses an interrupt feature, routed to the INT pin of the mikroBUS™ socket, which serves as an alarm or monitoring function to determine whether the ambient light level exceeds the upper threshold or goes below the lower threshold. The user can also configure the persistency of the interrupt pin, which reduces the possibility of false triggers, such as noise or sudden spikes in ambient light conditions. 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 2 Click hardware overview image

Features overview

Development board

Curiosity HPC, standing for Curiosity High Pin Count (HPC) development board, supports 28- and 40-pin 8-bit PIC MCUs specially designed by Microchip for the needs of rapid development of embedded applications. This board has two unique PDIP sockets, surrounded by dual-row expansion headers, allowing connectivity to all pins on the populated PIC MCUs. It also contains a powerful onboard PICkit™ (PKOB), eliminating the need for an external programming/debugging tool, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, a set of indicator LEDs, push button switches and a variable potentiometer. All

these features allow you to combine the strength of Microchip and Mikroe and create custom electronic solutions more efficiently than ever. Each part of the Curiosity HPC development board contains the components necessary for the most efficient operation of the same board. An integrated onboard PICkit™ (PKOB) allows low-voltage programming and in-circuit debugging for all supported devices. When used with the MPLAB® X Integrated Development Environment (IDE, version 3.0 or higher) or MPLAB® Xpress IDE, in-circuit debugging allows users to run, modify, and troubleshoot their custom software and hardware

quickly without the need for additional debugging tools. Besides, it includes a clean and regulated power supply block for the development board via the USB Micro-B connector, alongside all communication methods that mikroBUS™ itself supports. Curiosity HPC development board allows you to create a new application in just a few steps. Natively supported by Microchip software tools, it covers many aspects of prototyping thanks to many number of different Click boards™ (over a thousand boards), the number of which is growing daily.

Curiosity HPC double image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

8192

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
Interrupt
RB5
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Color 2 Click Schematic schematic

Step by step

Project assembly

Curiosity HPC front no-mcu image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity HPC as your development board.

Curiosity HPC front no-mcu image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
Prog-cut hardware assembly
Curiosity HPC Access 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
Necto DIP image step 7 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 2 Click driver.

Key functions:

  • color2_read_rgb - Function read red, green, and blue data from ISL29125

  • color2_rgb_to_hsl - This function converts RGB (red, green, blue) to HSL (hue, saturation, lightness) color value

  • color2_get_color - This function returns the color name flag from the input HSL color

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 
 * \brief Color 2 Click example
 * 
 * # Description
 * This example demonstrates the use of Color 2 Click board by reading data
 * from RGB channels and converting them to HSL color and displaying those data as 
 * well as the detected color name on the USB UART.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the Click default configuration.
 *
 * ## Application Task
 * Waits for the data ready interrupt, then reads the values of all channels and converts
 * them to HSL color and displays those data as well as the detected color name on the USB UART
 * every 100ms approximately.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "color2.h"

// ------------------------------------------------------------------ VARIABLES

static color2_t color2;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    color2_cfg_t cfg;

    /** 
     * 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.
    color2_cfg_setup( &cfg );
    COLOR2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    color2_init( &color2, &cfg );
    
    if ( COLOR2_ERROR == color2_default_cfg ( &color2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    // Wait for the data ready interrupt indication
    while ( color2_get_int_pin ( &color2 ) );
    
    uint8_t status = 0;
    color2_rgb_t rgb;
    if ( ( COLOR2_OK == color2_read_status ( &color2, &status ) ) && 
         ( COLOR2_OK == color2_read_rgb ( &color2, &rgb ) ) )
    {
        color2_hsl_t hsl;
        color2_rgb_to_hsl ( &color2, &rgb, &hsl );
        log_printf ( &logger, "\r\n Red: %u\r\n", rgb.red );
        log_printf ( &logger, " Green: %u\r\n", rgb.green );
        log_printf ( &logger, " Blue: %u\r\n", rgb.blue );
        log_printf ( &logger, " Hue: %.1f deg\r\n", hsl.hue );
        log_printf ( &logger, " Saturation: %.1f %%\r\n", hsl.saturation );
        log_printf ( &logger, " Lightness: %.1f %%\r\n", hsl.lightness );
        log_printf ( &logger, " Dominated color: " );
        switch ( color2_get_color ( &hsl ) )
        {
            case COLOR2_RED_COLOR:
            {
                log_printf ( &logger, "RED\r\n" );
                break;
            }
            case COLOR2_YELLOW_COLOR:
            {
                log_printf ( &logger, "YELLOW\r\n" );
                break;
            }
            case COLOR2_GREEN_COLOR:
            {
                log_printf ( &logger, "GREEN\r\n" );
                break;
            }
            case COLOR2_CYAN_COLOR:
            {
                log_printf ( &logger, "CYAN\r\n" );
                break;
            }
            case COLOR2_BLUE_COLOR:
            {
                log_printf ( &logger, "BLUE\r\n" );
                break;
            }
            case COLOR2_MAGENTA_COLOR:
            {
                log_printf ( &logger, "MAGENTA\r\n" );
                break;
            }
            case COLOR2_WHITE_COLOR:
            {
                log_printf ( &logger, "WHITE\r\n" );
                break;
            }
            case COLOR2_BLACK_COLOR:
            {
                log_printf ( &logger, "BLACK\r\n" );
                break;
            }
            default:
            {
                log_printf ( &logger, "UNKNOWN\r\n" );
                break;
            }
        }
    }
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}


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

Additional Support

Resources

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