Create advanced optical sensning solution based on TMD37253 and STM32F410RB
Precision in every shade: The future of light sensing
Published Oct 08, 2024
Click board™
Light mix-sens Click
Dev Board
Nucleo 64 with STM32F410RB MCU
Compiler
NECTO Studio
MCU
STM32F410RB
Experience the ultimate in sensor fusion with our all-in-one solution, providing precise proximity, color, and ambient light measurements for enhanced user experiences
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Hardware Overview
How does it work?
Light mix-sens Click is based on the TMD37253 slim module, from ams OSRAM, incorporates an IR LED and factory calibrated LED driver. The proximity detection feature provides object detection (e.g. mobile device screen to the user’s ear) by photodiode detection of reflected IR energy (sourced by the integrated LED). Detect/release events are interrupt-driven, and occur when proximity result crosses upper and/or lower threshold settings. The proximity engine features offset adjustment registers to compensate for unwanted IR energy reflection at the sensor. Proximity results are further improved by automatic ambient light subtraction. The ALS detection feature provides photopic light intensity data. The color photodiodes have UV and IR blocking filters and a dedicated data converters producing 16-bit data. This architecture allows applications to accurately measure ambient light which enables devices to calculate illuminance and color temperature to control display backlight and chromaticity. Proximity results are affected
by three fundamental factors: the integrated IR LED emission, IR reception, and environmental factors, including target distance and surface reflectivity. The IR reception signal path begins with IR detection from a photodiode and ends with the 8-bit proximity result in the PDATA register. A signal from the photodiode is amplified, and offset adjusted to optimize performance. Offset correction or cross-talk compensation is accomplished by adjustment to the POFFSET register. The analog circuitry of the device applies the offset value as a subtraction to the signal accumulation; therefore a positive offset value has the effect of decreasing the results. The color and ALS reception signal path begins as photodiodes receive filtered light and ends with 16-bit results. The IR photodiode primarily used for proximity sensing is multiplexed with the green channel’s ADC to measure the IR content of ambient light. The color photodiodes are filtered with UV and IR filters. The IR photodiode is filtered to receive only IR. A signal from the RGBC photodiodes
simultaneously accumulate for a period of time set by the value in ATIME before the results are available. Measurement of IR must be done in a separate integration because it shares the ADC with the green photodiode. Gain is adjustable from 1x to 128 x to facilitate the operation over a wide range of lighting conditions. Custom LUX equations are used to calculate the amount of ambient light, color temperature, as well as, determine the light type (e.g. LED, fluorescent, incandescent, etc.) using the ALS results. The TMD37253 module operates at 1.8V power supply with 1.8V I2C bus for reduced power consumption. For integration on Mikrobus, complete voltage regulation and logic level translation has been implemented. Therefore, this Click Board™ is designed to be operated only with a 3.3V logic level. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with logic levels of 5V.
Features overview
Development board
Nucleo-64 with STM32F410RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
128
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 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 STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32F410RB MCU as your development board.
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
Software Support
Library Description
This library contains API for Light mix-sens Click driver.
Key functions:
lightmixsens_write_byte- Generic Write Byte functionlightmixsens_read_byte- Generic Read Byte functionlightmixsens_switch_ir_to_prox- Switch IR To Proximity function
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* @file main.c
* @brief LightMixSens Click example
*
* # Description
* This example show usage of Light Mix Sens Click. It switches the IR light for separate and
* measure sectar of RGB lights. Click also measure proximity from the object using light source.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes all necessary peripherals and pins, initializes I2C driver and performs
* the Click board default configuration to allow ALS/Color and Proximity measurements.
*
* ## Application Task
* Waits until ALS/Color integration cycle was done and then reads the entire measurement.
* The all results will be sent to the selected UART terminal.
*
* ## Additional Functions :
* - prox_app - This is application function which determines the proximity results.
*
*
* @author MikroE Team
*
*/
#include "board.h"
#include "log.h"
#include "lightmixsens.h"
static lightmixsens_t lightmixsens;
static log_t logger;
lightmixsens_data_obj lightmixsens_data;
char prox_str[ 20 ];
// ------------------------------------------------------- ADDITIONAL FUNCTIONS
/**
* @brief Light mix sens proximity function.
* @details This is function which determines the proximity results.
*/
void prox_app ( void );
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
lightmixsens_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.
lightmixsens_cfg_setup( &cfg );
LIGHTMIXSENS_MAP_MIKROBUS( cfg, MIKROBUS_1 );
lightmixsens_init( &lightmixsens, &cfg );
lightmixsens_default_cfg( &lightmixsens );
lightmixsens_data.lightmixsens_cdata = LIGHTMIXSENS_DUMMY_DATA;
lightmixsens_data.lightmixsens_rdata = LIGHTMIXSENS_DUMMY_DATA;
lightmixsens_data.lightmixsens_gdata = LIGHTMIXSENS_DUMMY_DATA;
lightmixsens_data.lightmixsens_bdata = LIGHTMIXSENS_DUMMY_DATA;
lightmixsens_data.lightmixsens_pdata = LIGHTMIXSENS_DUMMY_DATA;
log_printf( &logger, "* Light mix-sens click initialization done. *\r\n" );
}
void application_task ( void )
{
lightmixsens_wait_atime( &lightmixsens );
lightmixsens_read_word( &lightmixsens, LIGHTMIXSENS_REG_CDATA,
&lightmixsens_data.lightmixsens_cdata );
lightmixsens_read_word( &lightmixsens, LIGHTMIXSENS_REG_RDATA,
&lightmixsens_data.lightmixsens_rdata );
lightmixsens_read_word( &lightmixsens, LIGHTMIXSENS_REG_GDATA_IRDATA,
&lightmixsens_data.lightmixsens_gdata );
lightmixsens_read_word( &lightmixsens, LIGHTMIXSENS_REG_BDATA,
&lightmixsens_data.lightmixsens_bdata );
lightmixsens_read_byte( &lightmixsens, LIGHTMIXSENS_REG_PDATA,
&lightmixsens_data.lightmixsens_pdata );
log_printf( &logger, "- Clear light: %.3d lx\r\n", lightmixsens_data.lightmixsens_cdata );
log_printf( &logger, "- Red light: %.3d lx\r\n", lightmixsens_data.lightmixsens_rdata );
log_printf( &logger, "- Green light: %.3d lx\r\n", lightmixsens_data.lightmixsens_gdata );
log_printf( &logger, "- Blue light: %.3d lx\r\n", lightmixsens_data.lightmixsens_bdata );
prox_app( );
log_printf( &logger, "** Proximity: %s\r\n", prox_str );
log_printf( &logger, "\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; ) {
application_task( );
}
}
void prox_app ( void )
{
float prox;
uint8_t cnt;
prox = lightmixsens_data.lightmixsens_pdata;
prox /= 255;
prox *= 16;
for ( cnt = 0; cnt < ( uint8_t ) prox; cnt++ ) {
prox_str[ cnt ] = '|';
}
prox_str[ cnt ] = 0;
}
// ------------------------------------------------------------------------ END
