Beginner
10 min

Track light intensity with precision using TSL2583 and ATmega328P

From light to digital data

Illuminance Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

Illuminance Click

Dev. board

Arduino UNO Rev3

Compiler

NECTO Studio

MCU

ATmega328P

Seamlessly integrate light intensity measurements into digital systems, enabling automation, analytics, and enhanced decision-making capabilities

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Hardware Overview

How does it work?

Illuminance Click is based on the TSL2583, a high-sensitivity light-to-digital converter from ams. The TSL2583 combines one broadband photodiode (visible plus infrared) and one infrared-responding photodiode on a single CMOS integrated circuit capable of providing a near-photopic response over an effective 16-bit dynamic range (16-bit resolution). Two integrating analog-to-digital converters (ADC) convert the photodiode currents to a digital output representing the irradiance measured on each channel. Besides general-purpose light sensing applications, the TSL2583 is explicitly designed for displays (LCD, OLED) to extend battery life and provide optimum viewing in diverse lighting conditions. The TSL2583 communicates with the MCU using the standard

I2C 2-Wire interface with a maximum frequency of 400kHz. Besides, it allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labeled I2C ADD. An integration of both ADC channels co-occurs. Upon completion of the conversion cycle, the conversion result is transferred to the Channel 0 and Channel 1 data registers, respectively. The transfers are double-buffered to ensure that the integrity of the data is maintained. After the transfer, the device automatically begins the next integration cycle. This sensor also supports an interrupt feature, routed to the INT pin on the mikroBUS™ socket, that simplifies and improves system efficiency by eliminating the need to poll a sensor for a light intensity value. The purpose of the interrupt

function is to detect a meaningful change in light intensity, where the user can define the concept of a significant change in light intensity and time or persistence. Users can define a threshold above and below the current light level, where an interrupt generates when the conversion value exceeds either of these limits. 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. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Illuminance Click hardware overview image

Features overview

Development board

Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an

ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the

first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.

Arduino UNO Rev3 double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

2048

You complete me!

Accessories

Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Arduino UNO 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
Interrupt
PC3
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PC5
SCL
I2C Data
PC4
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Illuminance Click Schematic schematic

Step by step

Project assembly

Click Shield for Arduino UNO front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Arduino UNO Rev3 as your development board.

Click Shield for Arduino UNO front image hardware assembly
Arduino UNO Rev3 front image hardware assembly
Barometer 13 Click front image hardware assembly
Prog-cut hardware assembly
Arduino UNO Rev3 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
Arduino UNO 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 Illuminance Click driver.

Key functions:

  • illuminance_set_atime - This function sets the timing register for the selected integration time

  • illuminance_set_gain - This function sets the gain level

  • illuminance_read_raw_data - This function checks if the data is ready and then reads the raw ADC data from two channels

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 Illuminance Click example
 * 
 * # Description
 * This example demonstrates basic Illuminance Click functionality.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initialize device and driver.
 * 
 * ## Application Task  
 * Every second calculate illuminance measured by sensor and log 
 * results to UART Terminal.
 * 
 * *note:* 
 * By default, integration time is set to 402ms but it may be modified
 * by user using illuminance_write_data() function and provided macros.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "illuminance.h"

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

static illuminance_t illuminance;
static log_t logger;

static uint16_t value_ch0;
static uint16_t value_ch1;
static uint16_t lux_value;
static uint16_t lux_value_old;
static uint8_t sensitivity;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    illuminance_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.

    illuminance_cfg_setup( &cfg );
    ILLUMINANCE_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    illuminance_init( &illuminance, &cfg );
    illuminance_default_cfg ( &illuminance );

    // Variable Initializations for this example.
    
    lux_value_old = 0;
    sensitivity = 50;
}

void application_task ( void )
{
    illuminance_get_result( &illuminance, &value_ch0, &value_ch1 );

    lux_value = illuminance_calculate_lux( ILLUMINANCE_TSL2561_GAIN_0X, ILLUMINANCE_TSL2561_INTEGRATIONTIME_402MS , value_ch0, value_ch1 );
    Delay_ms( 1000 );

    if ( ( ( lux_value - lux_value_old ) > sensitivity ) && ( ( lux_value_old - lux_value ) > sensitivity ) )
    {
        log_printf( &logger, "\r\n--------------------------------" );
        log_printf( &logger, "\r\nFull  Spectrum: %u [ lux ]", lux_value );
        log_printf( &logger, "\r\nVisible  Value: %u [ lux ]", value_ch0 - value_ch1 );
        log_printf( &logger, "\r\nInfrared Value: %u [ lux ]", value_ch1 );    
        log_printf( &logger, "\r\n--------------------------------\r\n" );
        
        lux_value_old = lux_value;
    }
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources

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