Intermediate
30 min
0

Monitor and control harmful pathogens with GUVC-T21GH and STM32F091RC for safer and cleaner environments

UVC: Lighting the way to health and safety

UVC Click with UNI Clicker

Published Sep 23, 2023

Click board™

UVC Click

Development board

UNI Clicker

Compiler

NECTO Studio

MCU

STM32F091RC

Upgrade health and safety standards with our UVC sensing solution, providing real-time data for informed decision-making

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Hardware Overview

How does it work?

UVC Click is based on GUVC-T21GH, an ultraviolet sensor from GenUV, capable of measuring UVC spectrum from 220nm up to 280nm and light intensity from 0mW/cm² up to 9.3mW/cm². Light intensity is converted into a digital value using MCP3221, a successive approximation A/D converter (ADC) with a 12-bit resolution. Communication to the MCP3221 is performed using a 2-wire, I2C-compatible interface. Standard (100 kHz) and Fast (400 kHz) I2C modes are available with the device. An on-chip conversion clock enables independent timing for the I2C and

conversion clocks. To get reliable readings from the sensor, ADC power and voltage reference are supplied from MCP1501T-33E/RW, a buffered voltage reference with 3.3V output capable of sourcing up to 20mA of current as a low-drift bandgap-based reference. The bandgap uses chopper-based amplifiers, effectively reducing the drift to zero. The second way of reading output voltage from the sensor is by placing a 0-ohm resistor on the JP2 position labeled on the PCB and reading an analog value from the AN pin on mikroBUS™. This way, you can rely on external

voltage reference and ADC with other desired specifications for your application and measure light power intensity up to 14.1 mW/cm². 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. Also, this 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.

UVC Click top side image
UVC Click bottom side image

Features overview

Development board

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI clicker double 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

Analog Output
PA0
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB6
SCL
I2C Data
PB7
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

UVC Click Schematic schematic

Step by step

Project assembly

UNI Clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.

UNI Clicker front image hardware assembly
Thermo 28 Click front image hardware assembly
SiBRAIN for STM32F745VG front image hardware assembly
Prog-cut hardware assembly
UNI Clicker MB 1 - upright/with-background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for UVC Click driver.

Key functions:

  • uvc_read_raw_data - This function reads 12bit raw data

  • uvc_get_voltage - This function calculate voltage from raw data

  • uvc_calculate_power - This function calculate power from voltage.

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 Uvc Click example
 * 
 * # Description
 * This click is capable of measuring UVC spectrum in the range of 220nm up to 280nm and light 
 * intensity from 0mW/cm² up to 9.3mW/cm². With high sensitivity and good solar blindness, 
 * it can be used for monitoring sterilization lamps.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver.
 * 
 * ## Application Task  
 * Reads sensor raw data and calculates voltage and power of UVC light.
 * The measured values will be displayed on the USB UART every 1500 ms.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "uvc.h"

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

static uvc_t uvc;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    uvc_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.

    uvc_cfg_setup( &cfg );
    UVC_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    uvc_init( &uvc, &cfg );
}

void application_task ( void )
{
    uint16_t raw_data;
    float voltage;
    float power;
    
    raw_data = uvc_read_raw_data( &uvc );
    log_printf( &logger, "Raw data: %d\r\n", raw_data );
    
    voltage = uvc_get_voltage( &uvc );
    log_printf( &logger, "Voltage: %.4f mV\r\n", voltage );

    power = uvc_calculate_power( voltage );
    log_printf( &logger, "Power: %.4f mW/cm2\r\n", power );

    log_printf( &logger, "----------------------\r\n" );
    Delay_ms( 1500 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources