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.
Features overview
Development board
EasyPIC v8 for PIC24/dsPIC33 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit PIC24/dsPIC33 microcontrollers from Microchip and has a broad set of unique functions, such as the first-ever embedded debugger/programmer. 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, EasyPIC v8 for PIC24/dsPIC33 provides a fluid and immersive working experience, allowing access anywhere and under any circumstances. Each part of the EasyPIC
v8 for PIC24/dsPIC33 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board 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 HOST/DEVICE, USB-UART, CAN, and LIN are also
included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 16-bit PIC24/dsPIC33 MCUs, from the smallest PIC24/dsPIC33 MCUs with only 14 up to 28 pins. EasyPIC v8 for PIC24/dsPIC33 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.
Microcontroller Overview
MCU Card / MCU

Architecture
dsPIC
MCU Memory (KB)
16
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
2048
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project assembly
Track your results in real time
Application Output
This Click board can be interfaced and monitored in two ways:
Application Output
- Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
UART Terminal
- Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.
Software Support
Library Description
This library contains API for RN4678 Click driver.
Key functions:
rn4678_enter_command_mode
- Enter the command mode functionrn4678_exit_command_mode
- Exit the command mode functionrn4678_set_device_name
- Set the device name 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
* \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