Dive into the depths of UV rays and go beyond the spectrum with AS7331 and PIC18F85K90
Unlocking the secrets of UVA/B/C rays
Published Nov 29, 2024
Click board™
UV 5 Click
Dev. board
UNI Clicker
Compiler
NECTO Studio
MCU
PIC18F85K90
Step into a new era of precision with our advanced spectral sensing solution - where every wavelength matters and accuracy is non-negotiable.
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Hardware Overview
How does it work?
UV 5 Click is based on the AS7331, a spectral UVA/B/C sensor from ams OSRAM. It converts optical radiation signals to a digital result by three photodiodes of three separated UVA, UVB, and UVC channels. This way, the sensor realizes a continuous or triggered measurement. You can adjust irradiance responsivity via gain, conversion time, and internal clock frequency to affect sensitivity, full-scale range, and LSB. The gain comes in a range of 12 steps divided by a factor of two for each step, while the conversion time is internally controlled over a range of 15 steps, again by a factor of two for each step. The AS7331 sensor operates in two different states. Configuration
state enables access to the configuration settings when a measurement is impossible. Measurement state has several modes: continuous measurement mode, command measurement mode, synchronous measurement mode, and synchronous measurement start and end mode. You define the measurement mode that the sensor over the software will perform. In addition, the sensor has power-saving options, such as power down and standby. UV 5 Click uses a standard 2-Wire I2C interface to communicate with the host MCU, supporting a bit rate of up to 400kbit/s. Select an I2C address over two ADDR SEL jumpers (0 is set by default). For externally
triggered start or start and stop of the measurement, you can synchronize the SYNC input of the AS7331, which is an externally controlled conversion input. The sensor will notify the end of each conversion over the RDY pin. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
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.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
PIC (8-bit)
MCU Memory (KB)
32
Silicon Vendor
Microchip
Pin count
80
RAM (Bytes)
2048
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for UV 5 Click driver.
Key functions:
uv5_get_rdy_pin- UV 5 get READY pin state function.uv5_sw_reset- UV 5 software reset function.uv5_channel_uva_read- UV 5 read raw UVA data function.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief UV 5 Click example
*
* # Description
* This example demonstrates the use of UV 5 click board by measuring
* the light irradiance of the UVA, UVB and UVC.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver, and performs the click default configuration.
*
* ## Application Task
* Measuring light irradiance level by reading data from the UV 5 click board
* approximately every 4 seconds and displaying it using UART Serial terminal.
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "uv5.h"
#define OUTCONV 4.194304 /* Conversion time duration expressed as the number of clock counts within this time
based on the default configuration. */
#define FSRE_UVA 1248 /* Full Scale Range of detectable input light irradiance Ee of the UVA channel
based on the default configuration. */
#define FSRE_UVB 1632 /* Full Scale Range of detectable input light irradiance Ee of the UVB channel
based on the default configuration. */
#define FSRE_UVC 784 /* Full Scale Range of detectable input light irradiance Ee of the UVC channel
based on the default configuration. */
static uv5_t uv5;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
uv5_cfg_t uv5_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.
uv5_cfg_setup( &uv5_cfg );
UV5_MAP_MIKROBUS( uv5_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == uv5_init( &uv5, &uv5_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( UV5_ERROR == uv5_default_cfg ( &uv5 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float temp_data;
uint16_t uv_raw_data;
float uv_data;
if ( uv5_get_rdy_pin( &uv5 ) == 1 )
{
uv5_temperature_read( &uv5, &temp_data );
log_printf( &logger, " Temp: %.2f degC\r\n", temp_data );
uv5_channel_uva_read( &uv5, &uv_raw_data );
uv_data = ( float ) ( ( FSRE_UVA / OUTCONV ) * uv_raw_data );
log_printf( &logger, " UVA: %.2f uW/cm2 \r\n", uv_data );
uv5_channel_uvb_read( &uv5, &uv_raw_data );
uv_data = ( float ) ( ( FSRE_UVB / OUTCONV ) * uv_raw_data );
log_printf( &logger, " UVB: %.2f uW/cm2 \r\n", uv_data );
uv5_channel_uvc_read( &uv5, &uv_raw_data );
uv_data = ( float ) ( ( FSRE_UVC / OUTCONV ) * uv_raw_data );
log_printf( &logger, " UVC: %.2f uW/cm2 \r\n", uv_data );
log_printf( &logger, " =================== \r\n" );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
