30 min

Enhance workplace safety and reduce the risk of UV-C exposure with 3535UVC1W and STM32F746ZG

See what's unseen

UVC Light Click with Fusion for STM32 v8

Published Sep 05, 2023

Click board™

UVC Light Click

Development board

Fusion for STM32 v8


NECTO Studio



Our innovative solution combines two 275nm UV-C LEDs with a green LED to provide a visual indicator, helping users identify and avoid direct exposure to potentially harmful UV-C light



Hardware Overview

How does it work?

UVC Light Click uses two 0.7W, 275nm LEDs and one green LED that allow users to see the approximate area where UVC light is shining since these UV wavelengths are not visible to the human eye and should avoid direct exposure to the eye. UVC Light Click can be used as a disinfection tool because DNA, RNA, and proteins absorb UV light in the range of 200 nm to 300 nm. Absorption by proteins can lead to the rupture of cell walls and the organism's death. Absorption by DNA or RNA (specifically by thymine bases) is

known to cause inactivation of the DNA or RNA double helix strands by forming thymine dimers. If enough of these dimers are created in DNA, the DNA replication process is disrupted, and the cell cannot replicate. It is widely accepted that it is not necessary to kill pathogens with UV light but rather apply enough UV light to prevent the organism from replicating. The UV doses required to prevent replication are orders of magnitude lower than required to kill, making the cost of UV treatment to prevent infection commercially

viable. UVC Light Click is implementing a TPS61169 LED driver with PWM brightness control to drive LEDs in series and an MC34671 battery charger to allow charging of battery when Click board™ is inserted in the mikroBUS™ socket; CHG LED will indicate the charging in progress and will turn off once the battery charging is finished. When the PWR SEL jumper is repositioned to the right position, you can use UVC Light and click standalone if no dimming is necessary or high mobility is needed.

UVC Light 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



8th Generation


ARM Cortex-M7

MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Dimming Control
Power Supply

Take a closer look


UVC Light 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
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN 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 UVC Light Click driver.

Key functions:

  • uvclight_pwm_start - This function starts PWM module

  • uvclight_set_duty_cycle - This function sets the PWM duty cycle

  • uvclight_pwm_stop - This function stops 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 UvcLight Click example
 * # Description
 * This click has ultraviolet LEDs with 275nm wavelength. UVC radiation refers to wavelengths 
 * shorter than 280 nm. Because of the spectral sensitivity of DNA, only the UVC region 
 * demonstrates significant germicidal properties.
 * The demo application is composed of two sections :
 * ## Application Init 
 * Initializes the driver.
 * ## Application Task  
 * Increases and decreases the pwm duty cycle.
 * Results are being sent to the Usart Terminal where you can track their changes.
 * CAUTION! High intensity UV Light - avoid eye and skin exposure. Avoid looking direclty at light!
 * @author Nikola Peric
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "uvclight.h"

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

static uvclight_t uvclight;
static log_t logger;

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

void application_init ( void )
    log_cfg_t log_cfg;
    uvclight_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.

    uvclight_cfg_setup( &cfg );
    uvclight_init( &uvclight, &cfg );

    uvclight_set_duty_cycle ( &uvclight, 0.0 );
    uvclight_pwm_start( &uvclight );
    Delay_ms( 100 );
    log_info( &logger, "---- Application Task ----" );

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

    uvclight_set_duty_cycle ( &uvclight, 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 ) 
        log_printf( &logger, "Cooldown 2 SEC\r\n");
        Delay_ms( 2000 );
        duty_inc = 1;
    duty_cnt += duty_inc;

void main ( void )
    application_init( );

    for ( ; ; )
        application_task( );

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

Additional Support