Intermediate
30 min

Enjoy in various high-power lighting applications with TPS61160A and STM32F030RC

Shine brighter, last longer

LED Driver 4 Click with Fusion for STM32 v8

Published Sep 05, 2023

Click board™

LED Driver 4 Click

Dev.Board

Fusion for STM32 v8

Compiler

NECTO Studio

MCU

STM32F030RC

Experience enhanced efficiency and performance in your electronic designs by incorporating our reliable LED driver solution

A

A

Hardware Overview

How does it work?

LED Driver 4 Click is based on the TPS61160A, a white LED driver with PWM brightness control, from Texas Instruments. The TPS61160A driver uses the boost converter topology with the current mode control. Its operation is very similar to a typical boost DC-DC converter with some additional features, useful for LED array driving. The Click board™ can provide up to 26V on the output terminals, after which the open LED sensing section will shut down the output stage MOSFET and the IC itself as a protection measure. This prevents the output voltage from exceeding the maximum ratings of the device in the case when the output LED is disconnected. The same will happen if the voltage at the feedback pin drops under 50% of its nominal value, 200 mV. The TPS61160A allows the PWM signal to be applied to its CTRL input, routed to the PWM pin of the mikroBUS™, labeled as CTL. The signal applied to this pin will modulate the feedback voltage on the FB pin, which, after being filtered through the LP filter, reduces the DC current on the output and through the LED array. This dimming technique will not produce any noise, as the DC current is scaled down, while the PWM is applied only to the internal feedback voltage. The PWM frequency should stay within 5 kHz to 100 kHz for optimum performance. The current through the LED

segments is sensed via the onboard resistor connected between the GND and the FB pin. It is chosen so that the maximum LED current is 20 mA. This is the optimal current for the white LEDs, providing the maximum brightness without LED deterioration. Note that while this is true for most of the white LEDs, the datasheet of the particular LEDs used with the LED Driver 4 click should be checked for the forward current parameter. It should be at least 20 mA. As explained above, the dimming function will reduce this current, resulting in a dimmer LED light. A soft-start function is built into the device, and it slowly ramps the voltage at the FB pin, resulting in a slow increase of the output voltage over about 6 ms, preventing high inrush currents. The internal current limit is also set to half the maximum current specification for the first 5 ms of operation. Applying the LOW logic level to the CTL pin for more than 2.5 ms will put the device into Shutdown mode. While in Shutdown mode, the current consumption is minimal. However, a current path still exists through the inductor and the Schottky diode. To prevent unwanted activation of the LED array, the minimum forward voltage of the LED array should be above the input voltage. The power supply for the LED array is connected via the VIN screw terminal, allowing an

external power source to be used. The rating of the external power source should stay within the range of 2V to 18V. The second screw terminal with the LED icon underneath connects the LED array. The maximum forward voltage of the LED array should stay below the device's minimum overprotection voltage, typically 25V. The maximum forward voltage of the LED element depends on the used LED type. It can be found in the datasheet of the used LED. The minimum overprotection voltage of the TPS61160A IC can be found in the TPS61160A, but it is also available in the Electrical Characteristics table below. Click board™ itself is powered via 5V mikroBUS™ rail. However, the Click board™ allows both 3.3V and 5V MCUs to drive its CTL input, as long as the voltage for the LOW logic level stays under 0.4V and the voltage for the HIGH logic level applied to this pin stays above 1.2V. The use of the Led Driver 4 click is easy and straightforward. However, MikroElektronika provides a library that contains functions compatible with the MikroElektronika compilers, which can be used for simplified LED array driving. The library also contains an example application that demonstrates their use. This example application can be used as a reference for custom designs.

LED Driver 4 Click hardware overview image

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.

Fusion for STM32 v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M0

MCU Memory (KB)

256

Silicon Vendor

STMicroelectronics

Pin count

64

RAM (Bytes)

32768

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
NC
NC
3.3V
Ground
GND
GND
Control/PWM Output
PB5
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

LED Driver 4 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for STM32 v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access 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 Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

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.

UART Application Output Step 1

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.

UART Application Output Step 2

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".

UART Application Output Step 3

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.

UART Application Output Step 4

Software Support

Library Description

This library contains API for LED Driver 4 Click driver.

Key functions:

  • leddriver4_set_duty_cycle - Generic sets PWM duty cycle

  • leddriver4_pwm_stop - Stop PWM module

  • leddriver4_pwm_start - Start PWM module.

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 LedDriver4 Click example
 * 
 * # Description
 * This click has the ability to dim the connected LED array, without producing any noise on the output.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the GPIO driver and
 * configures the PWM peripheral for controlling the LED array intensity.
 * 
 * ## Application Task  
 * Increases and decreases LED array intensity
 * ( first increases light intensity to the maximum and then decreases to the minimum ).
 * Results are being sent to the Usart Terminal where you can track their changes.
 * 
 * 
 * @author Nikola Peric
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "leddriver4.h"

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

static leddriver4_t leddriver4;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    leddriver4_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.

    leddriver4_cfg_setup( &cfg );
    LEDDRIVER4_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    leddriver4_init( &leddriver4, &cfg );
    
    leddriver4_set_duty_cycle ( &leddriver4, 0.0 );
    leddriver4_pwm_start( &leddriver4 );
    log_info( &logger, "---- Application Task ----" );
    Delay_ms( 500 );
}

void application_task ( void )
{
    static int8_t duty_cnt = 1;
    static int8_t duty_inc = 1;
    float duty = duty_cnt / 10.0;

    leddriver4_set_duty_cycle ( &leddriver4, duty );
    log_printf( &logger, "Duty: %d%%\r\n", ( uint16_t )( duty_cnt * 10 ) );
    Delay_ms( 500 );
    
    if ( 10 == duty_cnt ) 
    {
        duty_inc = -1;
    }
    else if ( 0 == duty_cnt ) 
    {
        duty_inc = 1;
    }
    duty_cnt += duty_inc;
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources