Track light intensity with precision using TSL2583 and STM32F207ZG
From light to digital data
Published Jun 21, 2023
Click board™
Illuminance Click
Dev. board
UNI Clicker
Compiler
NECTO Studio
MCU
STM32F207ZG
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.
Features overview
Development board
UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build
gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li
Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M3
MCU Memory (KB)
1024
Silicon Vendor
STMicroelectronics
Pin count
144
RAM (Bytes)
131072
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.
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 timeilluminance_set_gain- This function sets the gain levelilluminance_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
