Set new standards for capturing and interpreting colors with TCS3472 and STM32F746ZG
Colors in focus
Published 9月 22, 2023
Click board™
Color 7 Click
Dev Board
Fusion for STM32 v8
Compiler
NECTO Studio
MCU
STM32F746ZG
Discover a new realm of possibilities as you delve into the art and science of color sensing with our innovative solution
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Hardware Overview
How does it work?
Color 7 Click is based on the TCS3472 color light to digital converter with IR filter, from ams OSRAM. The color sensor is made out of a 4x3 matrix of photosensitive elements - photodiodes, which are placed under red, green, and blue colored filters. One group of photodiodes has no color filter, thus sensing the clear light. All the photodiodes are coated with an IR resistive layer, which prevents the influence of the IR part of the spectrum on the color readings. Besides the color sensing elements, the TCS3472 has four 16bit ADCs that convert the photodiode current into a 16bit value, available for reading. Finally, the TCS3472 IC contains a state machine, which controls the operation of the IC. After the Power ON reset, the device is set in the low power mode (Sleep mode). An I2C Start condition will wake up the device and it transitions to the Idle state. After checking the content of the Enable register PON bit. If set, the device will resume in Idle mode, and after setting the AEN bit of the Enable register, the sampling cycle is started. Another bit (WEN) determines if the device will start in Wait mode, or it will start the sampling cycle, with the integration time, defined by the user firmware. Integration time affects the sensitivity and the resolution of ADCs.
After the conversion is complete, the device returns to idle state, repeating the whole cycle, depending on the states of these bits. There are two modes of measurement available on this Click board™. It can use the CONT (continuous measurement), or the CMD (single measurement) measurement modes. The CONT mode outputs data continuously, using a time delay determined by the content of the BREAK register, while the CMD mode allows one measurement to be performed per command. After a single measurement is performed, the device can fall back to the Power Down or Standby state, while working in CMD mode. This is determined by the appropriate bits in the configuration registers and allows for a lower power consumption if required by the application. The interrupt engine allows low and high thresholds to be defined. The conversion value is compared with values set as the low and high threshold, and if any of the threshold values is exceeded, the interrupt event will be generated. The interrupt will assert the INT pin of the IC, routed to the mikroBUS™ INT pin. The interrupt pin will remain asserted until host clears the interrupt flag by the appropriate command. Another interrupt engine feature is the
persistence filter. This allows the number of the consecutive threshold exceed occurrences to be made before triggering an interrupt, avoiding erratic or false interrupt triggering. This pin is an open drain topology, and when asserted, it will be driven to a LOW logic state. It is set to a HIGH state when inactive, by the pull-up resistor. The Click board™ itself uses a very low number of external components. In fact, it only uses a few resistors for pulling the I2C/INT lines to a HIGH logic level when not asserted. The low number of external components simplify the design with this IC, allowing it to be used in a wide range of applications. I2C bus lines are routed to the appropriate mikroBUS™ pins, offering simple and reliable interfacing with the host MCU. Please note that this Click board™ can work only with 3.3V MCUs and it is not 5V tolerant. The device datasheet contains all the necessary information about the registers and their values. However, the Click board™ comes supported by a library, which contains functions which greatly simplify the development of the applications, cutting time to market.
Features overview
Development board
Fusion for STM32 v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from STMicroelectronics, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for STM32 v8 provides a fluid and immersive working experience, allowing
access anywhere and under any circumstances at any time. Each part of the Fusion for STM32 v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.
Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for STM32 v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development 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-M7
MCU Memory (KB)
1024
Silicon Vendor
STMicroelectronics
Pin count
144
RAM (Bytes)
327680
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 Fusion for STM32 v8 as your development board.
Track your results in real time
Application Output
After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.
Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.
In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".
The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.
Software Support
Library Description
This library contains API for Color 7 Click driver.
Key functions:
color7_get_color- Functions for detect colorscolor7_get_interrupt_state- Get interrut pin statecolor7_read_color_ratio- Functions for read color ratio
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
* \brief Color7 Click example
*
* # Description
* Demo application reads and detects colors - detected color logs on USBUART.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Configuring clicks and log objects.
* Settings the click in the default configuration.
*
* ## Application Task
* Reads light color and checks which color of light is detected by the sensor
* If the light color is detected, the detected color message is logged on the USBUART.
*
* *note:*
* Light source must be pointed towards sensor in order for sensor to
* detect light source color correctly.
* We used the HSL color palette on the monitor as an example.
*
* \author Katarina Perendic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "color7.h"
// ------------------------------------------------------------------ VARIABLES
static color7_t color7;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
color7_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.
color7_cfg_setup( &cfg );
COLOR7_MAP_MIKROBUS( cfg, MIKROBUS_1 );
color7_init( &color7, &cfg );
color7_default_cfg( &color7 );
log_info( &logger, "---- Start measurement ----" );
}
void application_task ( void )
{
uint8_t color;
// Task implementation.
color = color7_get_color( &color7 );
switch( color )
{
case 1:
{
log_printf( &logger, "--- Color: ORANGE \r\n" );
break;
}
case 2:
{
log_printf( &logger, "--- Color: RED \r\n" );
break;
}
case 3:
{
log_printf( &logger, "--- Color: PINK \r\n" );
break;
}
case 4:
{
log_printf( &logger, "--- Color: PURPLE \r\n" );
break;
}
case 5:
{
log_printf( &logger, "--- Color: BLUE \r\n" );
break;
}
case 6:
{
log_printf( &logger, "--- Color: CYAN \r\n" );
break;
}
case 7:
{
log_printf( &logger, "--- Color: GREEN \r\n" );
break;
}
case 8:
{
log_printf( &logger, "--- Color: YELLOW \r\n" );
break;
}
default:
{
// log_printf( &logger, "--- Color: UNRECOGNIZABLE \r\n" );
break;
}
}
Delay_100ms();
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
