20 min

Collect and transmit data across vast distances with RN2903 and TM4C1299NCZAD

915MHz long-range transceivers: Your bridge to the future

LR 2 Click with Fusion for Tiva v8

Published Nov 09, 2023

Click board™

LR 2 Click

Development board

Fusion for Tiva v8


NECTO Studio



With our 915MHz transceiver, you can unlock new possibilities in agriculture, environmental monitoring, and industrial control, thanks to their exceptional range and penetration capabilities.



Hardware Overview

How does it work?

LR 2 Click is based on the RN2903, a low-power, long-range RF technology-based transceiver module from Microchip Technology. It features the Class A LoRaWAN compliant stack, optimized for robust LoRaWAN networking, immune to interferences, and suitable for long-range wireless operation. It offers a long-range spread spectrum communication with high interference immunity. A receiver with a sensitivity of -148dBm combined with the 18.5dBm integrated amplifier allows for extended range links that can achieve up to 15km in an open area (by the module manufacturer specification). This Click board™ offers data rates of 300kbps with FSK modulation and 12500bps with LoRa Technology modulation and is associated with the 915MHz ISM band suitable for applications in the United States, Canada, Australia, and New Zealand. To join a LoRaWAN network, the RN2903 requires a LoRaWAN concentrator/gateway. The endpoint device has to

use a unique endpoint address, an application session key, and a network session key. The first method is called over-the-air activation (OTAA), where these keys are issued after a specific join procedure. The second method is to assign these keys manually, using UART commands. This method is called activation by personalization (ABP) and can be prone to some security issues. In any case, before an end device can communicate on the LoRaWAN network, it must be activated. LR 2 Click communicates with MCU using the UART interface with commonly used UART RX and TX pins, including the hardware flow control pins CTS and RTS (Clear to Send, Ready to Send) at data rates up to 57600bps for the data transfer. There are three groups of commands used to configure and operate the separate layers of the RN2903 (SYSTEM, MAC, and RADIO). Each layer controls a specific area of the module, and every UART command starts with one of the three keywords,

which represent an abbreviation of the layer name they are controlling. The module also has a non-volatile memory (EEPROM) for storing the configuration settings and some additional data. Also, this Click board™ can be reset through the Hardware Reset pin, labeled as RST on the mikroBUS™ socket, by setting this pin to a low logic state. LR 2 Click features the SMA antenna connector with an impedance of 50Ω, so it can be equipped with the appropriate 915MHz compliant antenna that MIKROE offers. 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.

LR 2 Click hardware overview image

Features overview

Development board

Fusion for TIVA 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 Texas Instruments, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over a WiFi network. 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 TIVA v8 provides a fluid and immersive working experience, allowing access

anywhere and under any circumstances at any time. Each part of the Fusion for TIVA 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 TIVA 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 Tiva v8 horizontal image

Microcontroller Overview

MCU Card / MCU



8th Generation


ARM Cortex-M4

MCU Memory (KB)


Silicon Vendor

Texas Instruments

Pin count


RAM (Bytes)


You complete me!


Rubber Antenna GSM/GPRS Right Angle is the perfect companion for all GSM Click boards™ in our extensive lineup. This specialized antenna is designed to optimize your wireless connectivity with impressive features. With a wide frequency range spanning 824-894/1710-1990MHz or 890-960/1710-1890MHz, it can handle various frequency bands, ensuring a seamless and reliable connection. The antenna boasts an impedance of 50 Ohms and a gain of 2dB, enhancing signal reception and transmission. Its 70/180MHz bandwidth provides flexibility for diverse applications. The vertical polarization further enhances its performance. With a maximum input power capacity of 50W, this antenna ensures robust communication even under demanding conditions. Measuring a compact 50mm in length and featuring an SMA male connector, the Rubber Antenna GSM/GPRS Right Angle is a versatile and compact solution for your wireless communication needs.

LR 2 Click accessories image

Used MCU Pins

mikroBUS™ mapper

Power Supply
Power Supply

Take a closer look


LR 2 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 Tiva 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 LR 2 Click driver.

Key functions:

  • lr_mac_tx - Function for writing mac parameters

  • lr_join - Function for setting join mode

  • lr_tick_conf - Timer Configuration

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 main.c
 * @brief LR Click Example.
 * # Description
 * This example reads and processes data from LR clicks.
 * The demo application is composed of two sections :
 * ## Application Init 
 * Initializes driver init and LR init.
 * ## Application Task  
 * Transmitter mode - sends one by one byte sequence of the desired message each second and 
 * checks if it is sent successfully.
 * Receiver mode - displays all the received characters on USB UART.
 * ## Additional Functions
 * - lr_process ( ) - The general process of collecting data the module sends.
 * - bool is_digit ( char c ) - Checks if input is a digit 
 * - hex_to_int ( char* origin, uint8_t* result ) - Converts hexadecimal to int value.
 * @author Stefan Ilic

#include "board.h"
#include "log.h"
#include "lr.h"
#include "string.h"
#include "conversions.h"


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


static lr_t lr;
static log_t logger;

uint8_t cnt;
uint8_t send_data;
int8_t  int_data;
uint8_t rx_state;
uint8_t tx_state;

char send_hex[ 50 ];
char tmp_txt[ 50 ];
uint8_t send_message[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13, 10, 0 };

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

static void lr_process ( void ) {
    int32_t rsp_size;
    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint8_t check_buf_cnt;
    uint8_t process_cnt = PROCESS_COUNTER;
    while ( process_cnt != 0 ) {
        rsp_size = lr_generic_read( &lr, &uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );

        if ( rsp_size > 0 ) {  
            // Validation of the received data
            for ( check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ ) {
                lr_put_char( &lr, uart_rx_buffer[ check_buf_cnt ] );
                lr_isr_process( &lr );
            // Clear RX buffer
            memset( uart_rx_buffer, 0, PROCESS_RX_BUFFER_SIZE );
        } else {
            // Process delay 
            Delay_ms( 100 );

bool is_digit ( char c ) {
    if ( c >= '0' && c <= '9' ) {
        return true;

    return false;

void hex_to_int ( char* origin, uint8_t* result ) {
    uint8_t len = strlen( origin );
    uint8_t idx, ptr, factor;

    if ( len > 0 ) {
        *result = 0;
        factor = 1;

        for ( idx = len - 1; idx >= 0; idx-- ) {
            if ( is_digit( *( origin + idx ) ) ) {
                *result += ( *( origin + idx ) - '0' ) * factor;
               } else {
                    if ( *( origin + idx ) >= 'A' && *( origin + idx ) <= 'Z' ) {
                        ptr = ( *( origin + idx ) - 'A' ) + 10;
                    } else {
                    *result += ( ptr * factor );
                factor *= 16;

void lr_cbk( char* response ) {

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

void application_init ( void ) {
    log_cfg_t log_cfg;
    lr_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.

    lr_cfg_setup( &cfg );
    lr_init( &lr, &cfg );

    lr_default_cfg( &lr, 0, &lr_cbk );

    lr_cmd( &lr, LR_CMD_SYS_GET_VER, &tmp_txt[ 0 ] );

    lr_cmd( &lr, LR_CMD_MAC_PAUSE,  &tmp_txt[ 0 ] );
    log_printf( &logger, "mac pause\r\n" );
    for ( cnt = 0; cnt < 10; cnt++ ) {
        log_printf( &logger, "%c", tmp_txt[ cnt ] );

    log_printf( &logger, "\r\n" );

    lr_cmd( &lr, LR_CMD_RADIO_SET_WDT, &tmp_txt[ 0 ] );

    log_printf( &logger, "radio set wdt 0\r\n" );
    log_printf( &logger, "%s\r\n", &tmp_txt[ 0 ] );

void application_task ( void ) {
    char *ptr;
    lr_process( );
    rx_state = lr_rx( &lr, LR_ARG_0, &tmp_txt[ 0 ] );
    if ( rx_state == 0 ) {
        tmp_txt[ 12 ] = 0;
        ptr = ( char* )&int_data;
        hex_to_int( &tmp_txt[ 10 ], ptr );

        log_printf( &logger, "%c", int_data  );

    for ( cnt = 0; cnt < 9; cnt++ ) {
        send_data = send_message[ cnt ] ;
        int8_to_hex( send_data, send_hex );
        tx_state = lr_tx( &lr, &send_hex[ 0 ] );
        if ( tx_state == 0 ) {
            log_printf( &logger, "  Response : %s\r\n", &tmp_txt[ 0 ] );
        Delay_ms( 1000 );

void main ( void ) {
    application_init( );

    for ( ; ; ) {
        application_task( );

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

Additional Support