Intermediate
30 min

Achieve fast data transfer with some Bluetooth magic thanks to the RN4678 and PIC18F57Q43

Break free from cables

RN4678 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

RN4678 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Explore how this wireless method serves as a convenient alternative to cables, empowering users with effortless data exchange and intuitive device management for enhanced connectivity and productivity

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Hardware Overview

How does it work?

RN4678 Click is based on the RN4678, a Bluetooth® 4.2 dual-mode module from Microchip. This Click is designed to run on a 3.3V power supply. It communicates with the target microcontroller over I2C and UART interface, with additional functionality provided by the following pins on the mikroBUS™ line: AN, RST, CS, PWM, INT. The RN4678 from Microchip is a fully certified Bluetooth version 4.2 module. Use it to add Bluetooth wireless capability to your project.

The module includes an onboard Bluetooth stack, power management subsystem, 2.4 GHz transceiver, and RF power amplifier. Data transfer is achieved through Bluetooth by sending or receiving data through SPP in Bluetooth (BT) Classic mode and Transparent UART in BLE mode. The RN4678 contains an integral ceramic chip antenna. The RN4678 module has strong AES128 Encryption. 128-bit encryption is one of the most robust encryption algorithms. AES stands for

Advanced Encryption Standard, a symmetric encryption algorithm. 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.

RN4678 Click hardware overview image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Software Button
PA0
AN
Module Reset
PA7
RST
UART RTS
PD4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Sleep Wake
PB0
PWM
UART CTS
PA6
INT
UART TX
PC3
TX
UART RX
PC2
RX
I2C Clock
PB2
SCL
I2C Data
PB1
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

RN4678 Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Barometer 13 Click front image hardware assembly
PIC18F57Q43 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Curiosity Nano with PICXXX 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
PIC18F57Q43 Curiosity MCU 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 via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for RN4678 Click driver.

Key functions:

  • rn4678_enter_command_mode - Enter the command mode function

  • rn4678_exit_command_mode - Exit the command mode function

  • rn4678_set_device_name - Set the device name function

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 RN4678 Click example
 * 
 * # Description
 * This example reads and processes data from RN4678 clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and configures the click board.
 * 
 * ## Application Task  
 * Checks for the received data, reads it and replies with a certain message.
 * 
 * ## Additional Function
 * - rn4678_process ( ) - Logs all the received messages/responses on the USB UART, 
 *                        and if it receives "Hello" string it sends the certain message 
 *                        back to the connected device.
 * 
 * @note
 * We have used the Serial Bluetooth Terminal smartphone application for the test. 
 * A smartphone and the click board must be paired in order to exchange messages with each other.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rn4678.h"
#include "string.h"

#define PROCESS_COUNTER 20
#define PROCESS_RX_BUFFER_SIZE 100
#define PROCESS_PARSER_BUFFER_SIZE 100

#define PROCESS_RSP_ERROR  -1
#define PROCESS_RSP_OK     1
#define PROCESS_NO_RSP     0
#define PROCESS_LOG_RSP    0

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

static rn4678_t rn4678;
static log_t logger;

uint8_t DEVICE_NAME_DATA[ 20 ] = { 'R', 'N', '4', '6', '7', '8', ' ', 'c', 'l', 'i', 'c', 'k' };
uint8_t EXTENDED_STRING_DATA[ 10 ] = { 'S', 'l', 'a', 'v', 'e' };
uint8_t PIN_CODE_DATA[ 10 ] = { '1', '2', '3', '4' };
static char current_parser_buf[ PROCESS_PARSER_BUFFER_SIZE ];

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

static int8_t rn4678_process ( char * response )
{
    int32_t rsp_size;
    uint16_t rsp_cnt = 0;
    
    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint8_t check_buf_cnt;
    uint8_t process_cnt = PROCESS_COUNTER;
    int8_t rsp_flag = 0;
    
    // Clear current buffer
    memset( current_parser_buf, 0, PROCESS_PARSER_BUFFER_SIZE ); 
    
    while( process_cnt != 0 )
    {
        rsp_size = rn4678_generic_read( &rn4678, 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++ )
            {
                if ( uart_rx_buffer[ check_buf_cnt ] == 0 ) 
                {
                    uart_rx_buffer[ check_buf_cnt ] = 13;
                }
            }
            // Storages data in current buffer
            rsp_cnt += rsp_size;
            if ( rsp_cnt < PROCESS_PARSER_BUFFER_SIZE )
            {
                strncat( current_parser_buf, uart_rx_buffer, rsp_size );
            }
            
            // Clear RX buffer
            memset( uart_rx_buffer, 0, PROCESS_RX_BUFFER_SIZE );
            
            if ( strstr( current_parser_buf, "ERR" ) ) {
                Delay_100ms( );
                rsp_flag = PROCESS_RSP_ERROR;
                break;
            }
            
            if ( PROCESS_LOG_RSP != response )
            {
                if ( strstr( current_parser_buf, response ) ) {
                    Delay_100ms( );
                    rsp_flag = PROCESS_RSP_OK;
                    break;
                }
            }
            else
            {
                rsp_flag = PROCESS_RSP_OK;
                process_cnt = 1;
            }
            
            if ( strstr( current_parser_buf, "Hello" ) ) {
                rn4678_generic_write( &rn4678, "MikroE\r\n", 8 );
                Delay_100ms( );
                break;
            }
        } 
        else 
        {
            process_cnt--;
            
            // Process delay 
            Delay_ms( 100 );
        }
    }
    
    if ( PROCESS_NO_RSP != rsp_flag )
    {
        log_printf( &logger, "%s", current_parser_buf );
        log_printf( &logger, "\r\n---------------------------\r\n" );
        return rsp_flag;
    }
    
    return PROCESS_NO_RSP;
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    rn4678_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.

    rn4678_cfg_setup( &cfg );
    RN4678_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rn4678_init( &rn4678, &cfg );

    rn4678_enable ( &rn4678 );
    Delay_ms( 1000 );
    rn4678_hw_reset ( &rn4678 );
    Delay_ms( 1000 );
    
    log_printf( &logger, "Configuring the module...\n" );
    
    do
    {    
        log_printf( &logger, " --- Command mode --- \r\n" );
        rn4678_enter_command_mode( &rn4678 );
    }
    while( rn4678_process( "CMD" ) != 1 );
    
    do
    {
        log_printf( &logger, " --- Device name --- \r\n" );
        rn4678_set_device_name( &rn4678, &DEVICE_NAME_DATA[ 0 ] );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Status string --- \r\n" );
        rn4678_set_extended_status_string( &rn4678, &EXTENDED_STRING_DATA[ 0 ] );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Operating mode --- \r\n" );
        rn4678_set_operating_mode( &rn4678, 0 );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Authentication --- \r\n" );
        rn4678_set_authentication( &rn4678, 1 );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Pin code --- \r\n" );
        rn4678_set_security_pin_code( &rn4678, &PIN_CODE_DATA[ 0 ] );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Exit command mode --- \r\n" );
        rn4678_exit_command_mode( &rn4678 );
    }
    while( rn4678_process( "END" ) != 1 );
    
    log_printf( &logger, "The module has been configured.\n" );
    
    rn4678_set_cts_pin( &rn4678, 0 );
}

void application_task ( void )
{
    rn4678_process( PROCESS_LOG_RSP );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources

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