Achieve stunning color mixing with TLC5947 and STM32F107VCT6
Brighten up your life and illuminate your world
Published Apr 24, 2023
Click board™
LED Driver 18 Click
Dev Board
EasyMx PRO v7a for STM32
Compiler
NECTO Studio
MCU
STM32F107VCT6
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Hardware Overview
How does it work?
LED Driver 18 Click is based on the TLC5947, a 24-channel 12-bit PWM LED driver from Texas Instruments. Each channel supports many LEDs in series connected to the LED terminal and has an individually-adjustable 4096-step PWM grayscale brightness control accessible through a serial interface port. It has a programmable current value of all 24 channels achievable through the AD5171, an I2C-configurable digital potentiometer, with a maximum of 30mA of LED current per channel. The TLC5947 also features a built-in thermal shutdown function that turns OFF all output drivers during an over-temperature condition.
All channels automatically restart when the temperature returns to normal conditions. LED Driver 18 Click communicates with MCU through a register-selectable standard SPI interface that enables a high clock speed of up to 30MHz for optimum performance. In addition to the interface signals, the TLC5947 uses another signal from the mikroBUS™ socket. The enable signal routed on the EN pin of the mikroBUS™ socket provides the ability to turn OFF all constant-current outputs. When the EN pin is in a high logic state, all channels (0-23) are forced OFF, the grayscale PWM timing controller initializes, and the grayscale counter
resets to 0. When the EN pin is in a low logic state is low, the grayscale PWM timing controller controls all LED channels. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.
Features overview
Development board
EasyMx PRO v7a for STM32 is the seventh generation of ARM development boards specially designed to develop embedded applications rapidly. It supports a wide range of 32-bit ARM microcontrollers from STMicroelectronics and a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. 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. With two different connectors for each port, EasyMx PRO v7afor STM32 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of the EasyMx
PRO v7a for STM32 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply block for the development board. It can use a wide range of external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB-HOST/DEVICE, CAN, and
Ethernet are also included, including the well-established mikroBUS™ standard, one display option for the TFT board line of products, and a standard TQFP socket for the seventh-generation MCU cards. This socket covers 32-bit ARM MCUs like STM32 Cortex-M3, -M7, and -M4 MCUs. EasyMx PRO v7afor STM32 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
7th Generation
Architecture
ARM Cortex-M3
MCU Memory (KB)
10
Silicon Vendor
STMicroelectronics
Pin count
100
RAM (Bytes)
100
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 EasyMx PRO v7a for STM32 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 LED Driver 18 Click driver.
Key functions:
leddriver18_set_output_pwmLED Driver 18 set output channel PWM value function.leddriver18_write_configLED Driver 18 write config function.leddriver18_set_cc_outputLED Driver 18 set constant current output 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 LED Driver 18 Click example
*
* # Description
* This library contains API for LED Driver 18 Click driver.
* The library initializes and defines the I2C bus drivers to
* write and read data for setting constant current output,
* as well as the default configuration for a PWM output value
* of the OUT pins.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs default configuration and sets
* the device in output enabled mode.
*
* ## Application Task
* This example demonstrates the use of the LED Driver 18 Click board by
* changing PWM values for all output from a minimum value to
* maximum value and back to minimum controlling the brightness of the
* LEDs in the process.
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "leddriver18.h"
static leddriver18_t leddriver18;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
leddriver18_cfg_t leddriver18_cfg; /**< Click config object. */
/**
* 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.
leddriver18_cfg_setup( &leddriver18_cfg );
LEDDRIVER18_MAP_MIKROBUS( leddriver18_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == leddriver18_init( &leddriver18, &leddriver18_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( LEDDRIVER18_ERROR == leddriver18_default_cfg ( &leddriver18 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float pwm_val;
for ( int8_t n_cnt = 0; n_cnt <= 100; n_cnt += 10 )
{
for ( uint8_t out_cnt = 0; out_cnt < LEDDRIVER18_MAX_OUTPUT_NUM; out_cnt++ )
{
leddriver18_set_output_pwm( out_cnt, n_cnt );
}
pwm_val = leddriver18_get_output_pwm( 0 );
log_printf( &logger, " PWM value: %.2f \r\n", pwm_val );
leddriver18_write_config( &leddriver18 );
Delay_ms( 200 );
}
for ( int8_t n_cnt = 100; n_cnt >= 10; n_cnt -= 10 )
{
for ( uint8_t out_cnt = 0; out_cnt < LEDDRIVER18_MAX_OUTPUT_NUM; out_cnt++ )
{
leddriver18_set_output_pwm( out_cnt, n_cnt );
}
pwm_val = leddriver18_get_output_pwm( 0 );
log_printf( &logger, " PWM value: %.2f \r\n", pwm_val );
leddriver18_write_config( &leddriver18 );
Delay_ms( 200 );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
