Intermediate
20 min

Achieve long-range, low-power communication ideal for IoT applications with RA-08 and STM32F031K6

LoRa module for ultra-long distance spread spectrum communications

LR 9 Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

LR 9 Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Ideal for sectors requiring long-distance, low-power communication, such as smart metering, supply chain and logistics, home automation, and security systems

A

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Hardware Overview

How does it work?

LR 9 Click is based on the RA-08, a LoRaWAN module from Ai-Thinker Technology. This module is made for ultra-long-range spread spectrum communication tasks powered by the ASR6601. The ASR6601, an LPWAN wireless communication system-on-chip (SoC), combines RF transceivers, modems, and a 32-bit RISC microcontroller (MCU). The embedded MCU, leveraging an ARM core, operates at a frequency of 48MHz. The RA-08 is designed to work with LoRa modulation and the conventional (G)FSK modulation within the LPWAN domain. Furthermore, it supports BPSK and (G)MSK modulation for transmission, with the receiver accommodating (G)MSK modulation. Designed for LPWAN applications, the RA-08 module delivers long-distance, ultra-low power connectivity. It finds its applications in various sectors, including smart metering, supply chain and logistics management, building automation for homes, security systems, and remote-controlled

irrigation systems. Diving deeper into the specifics, the module supports a frequency range from 410MHz to 525MHz and can transmit at a maximum power of +22dBm. It boasts embedded storage with 128KB of FLASH and 16KB of SRAM, alongside support for several sleep modes, with a deep sleep current as low as 0.9uA. Additional functionalities of the LR 9 Click include communication capabilities with the host MCU via a UART interface, set by default to a baud rate of 115200bps. A switch on the board allows the selection of the UART interface's function—either as the main serial communication port for exchanging AT commands (in the LPRX position) or as a serial port for firmware flashing (in the RX position). Moreover, for developers looking to build their software from scratch, the module also includes I2C communication capabilities. The board does not limit itself to UART and I2C interface pins; it also features pins like the RST pin for module

resetting (which can also be achieved through a RESET button) and a BT pin for firmware flashing (accessible through a BOOT button). This frees programming and software development through the SWD interface pins on the board's right side. Also, an RGB LED serves as a module status indicator and is configurable by the user. LR 9 Click also features the SMA antenna connector with an impedance of 50Ω, compatible with various antennas available from MIKROE, like the Rubber Antenna 433MHz, to enhance its connectivity. 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.

LR 9 Click hardware overview image

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Right angle 433MHz rubber antenna boasts a frequency range of 433MHz, ensuring optimal performance within this spectrum. With a 50Ohm impedance, it facilitates efficient signal transmission. The antenna's vertical polarization enhances signal reception in a specific orientation. Featuring a 1.5dB gain, it can improve signal strength to some extent. The antenna can handle a maximum input power of 50W, making it suitable for various applications. Its compact 50mm length minimizes spatial requirements. Equipped with an SMA male connector, it easily interfaces with compatible devices. This antenna is an adaptable solution for wireless communication needs, particularly when vertical polarization is crucial.

LR 9 Click accessories 1 image

Used MCU Pins

mikroBUS™ mapper

FW Flash
PA0
AN
Reset
PA11
RST
ID COMM
PA4
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
UART TX
PA10
TX
UART RX
PA9
RX
I2C Clock
PB6
SCL
I2C Data
PB7
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

LR 9 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
Stepper 22 Click front image hardware assembly
Prog-cut hardware assembly
Stepper 22 Click complete accessories setup image hardware assembly
Nucleo-32 with STM32 MCU 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 image step 5 hardware assembly
Necto image step 6 hardware assembly
STM32 M4 Clicker HA MCU/Select Step 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

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 LR 9 Click driver.

Key functions:

  • lr9_send_data_frame - This function sends the desired data frame by using the UART serial interface

  • lr9_inquire_command - Using the UART serial interface, this function writes the desired query command with or without the included equals symbol

  • lr9_write_command - This function writes a desired command and parameter by using the UART serial interface

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 LR 9 Click Example.
 *
 * # Description
 * This example demonstrates the use of LR 9 click board by processing
 * the incoming data and displaying them on the USB UART.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs a hardware reset of the device.
 *
 * ## Application Task
 * Depending on the selected mode, the application demo 
 * receives and processes all incoming data or sends the LoRa packet demo string.
 * Results are being sent to the UART Terminal, where you can track their changes.
 *
 * ## Additional Function
 * - static void lr9_clear_app_buf ( void )
 * - static void lr9_log_app_buf ( void )
 * - static void lr9_log_receiver ( void )
 * - static void lr9_log_response ( void )
 * - static err_t lr9_process ( lr9_t *ctx )
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "lr9.h"
#include "conversions.h"

// Comment the line below to switch application mode to receiver
#define DEMO_APP_TRANSMITTER

// Default RF configuration
#define LR9_RF_CFG_DEFAULT_TX       "433000000,1,1,1,22,1"
#define LR9_RF_CFG_DEFAULT_RX       "433000000,1,1,1,1"
#define LR9_DEMO_STRING             "MikroE"

// Receiver string sequences
#define PROCESS_START_RECEIVE       "Recv:"
#define PROCESS_ATDTRX              "AT"

// Response timeout
#define RESPONSE_TIMEOUT            100000

// Application buffer size
#define APP_BUFFER_SIZE             500
#define PROCESS_BUFFER_SIZE         200

static lr9_t lr9;
static log_t logger;

static uint8_t app_buf[ APP_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;

/**
 * @brief LR 9 clearing application buffer.
 * @details This function clears memory of application buffer and reset its length.
 * @note None.
 */
static void lr9_clear_app_buf ( void );

/**
 * @brief LR 9 log application buffer.
 * @details This function logs data from application buffer to USB UART.
 * @note None.
 */
static void lr9_log_app_buf ( void );

/**
 * @brief LR 9 log receiver data.
 * @details This function logs data from receiver application buffer to USB UART.
 * @note None.
 */
static void lr9_log_receiver ( void );

/**
 * @brief LR 9 log response.
 * @details This function reads data from device and 
 * concatenates and logs data to application buffer to USB UART.
 * @note None.
 */
static void lr9_log_response ( void );

/**
 * @brief LR 9 data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @param[in] ctx : Click context object.
 * See #lr9_t object definition for detailed explanation.
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t lr9_process ( lr9_t *ctx );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    lr9_cfg_t lr9_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.
    lr9_cfg_setup( &lr9_cfg );
    LR9_MAP_MIKROBUS( lr9_cfg, MIKROBUS_1 );
    if ( UART_ERROR == lr9_init( &lr9, &lr9_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    lr9_hw_reset( &lr9 );
    Delay_ms( 500 );

    lr9_inquire_command( &lr9, LR9_CMD_CTXADDRSET, LR9_EQUAL_ENABLE );
    lr9_log_response( );
    Delay_ms( 500 );

    lr9_inquire_command( &lr9, LR9_CMD_CADDRSET, LR9_EQUAL_ENABLE );
    lr9_log_response( );
    Delay_ms( 500 );

#ifdef DEMO_APP_TRANSMITTER
    log_printf( &logger, " > Transmitter < \r\n" );
    lr9_write_command( &lr9, LR9_CMD_CTX , LR9_RF_CFG_DEFAULT_TX );
    lr9_log_response( );
    Delay_ms( 500 );
#else
    log_printf( &logger, " > Receiver < \r\n" );
    lr9_write_command( &lr9, LR9_CMD_CRXS , LR9_RF_CFG_DEFAULT_RX );
    lr9_log_response( );
    Delay_ms( 500 );
#endif

    lr9_log_response( );
    Delay_ms( 500 );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    lr9_send_data_frame( &lr9, LR9_DTRX_CONFIG_DATA, LR9_NB_TRIALS_2, LR9_DEMO_STRING );
    lr9_log_response( );
    Delay_ms( 2000 );
#else
    lr9_log_receiver( );
#endif
}

int main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
    
    return 0;
}

static void lr9_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
}

static void lr9_log_app_buf ( void )
{
    for ( int32_t buf_cnt = 0; buf_cnt < app_buf_len; buf_cnt++ )
    {
        log_printf( &logger, "%c", app_buf[ buf_cnt ] );
    }
}

static void lr9_log_receiver ( void )
{
    uint32_t timeout_cnt = 0;
    lr9_clear_app_buf( );
    lr9_process( &lr9 );
    while ( 0 == strstr( app_buf, PROCESS_START_RECEIVE ) )
    {
        lr9_process( &lr9 );
        if ( timeout_cnt++ > RESPONSE_TIMEOUT )
        {
            lr9_clear_app_buf( );
            log_printf( &logger, " Timeout\r\n" );
            break;
        }
        Delay_ms( 1 );
    }
    lr9_process( &lr9 );
    if ( strstr( app_buf, PROCESS_ATDTRX ) )
    {
        log_printf( &logger, " Receive: " );
        for ( int32_t buf_cnt = 15; buf_cnt < 15 + strlen( LR9_DEMO_STRING ); buf_cnt++ )
        {
            log_printf( &logger, "%c", app_buf[ buf_cnt ] );
        }
        log_printf( &logger, "\r\n" );
    }
    lr9_clear_app_buf( );
}

static void lr9_log_response ( void )
{
    if ( LR9_OK == lr9_process( &lr9 ) ) 
    {
        lr9_log_app_buf( );
        lr9_clear_app_buf( );
    }
}

static err_t lr9_process ( lr9_t *ctx ) 
{
    uint8_t rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    int32_t overflow_bytes = 0;
    int32_t rx_cnt = 0;
    int32_t rx_size = lr9_generic_read( ctx, rx_buf, PROCESS_BUFFER_SIZE );
    if ( ( rx_size > 0 ) && ( rx_size <= APP_BUFFER_SIZE ) ) 
    {
        if ( ( app_buf_len + rx_size ) > APP_BUFFER_SIZE ) 
        {
            overflow_bytes = ( app_buf_len + rx_size ) - APP_BUFFER_SIZE;
            app_buf_len = APP_BUFFER_SIZE - rx_size;
            memmove ( app_buf, &app_buf[ overflow_bytes ], app_buf_len );
            memset ( &app_buf[ app_buf_len ], 0, overflow_bytes );
        }
        for ( rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) 
        {
            if ( rx_buf[ rx_cnt ] ) 
            {
                app_buf[ app_buf_len++ ] = rx_buf[ rx_cnt ];
            }
        }
        return LR9_OK;
    }
    return LR9_ERROR;
}

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

Additional Support

Resources

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