Intermediate
30 min
0

Create an easy-to-use/drop-in solution based on BLE 4.2 with RN4870 and PIC18LF26K40

Simplify connectivity

RN4870 click with EasyPIC v8

Published Nov 01, 2023

Click board™

RN4870 click

Development board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18LF26K40

A

A

Hardware Overview

How does it work?

RN4870 Click is based on the RN4870, a Bluetooth® 4.2 low-energy module from Microchip. The Click is designed to run on a 3.3V power supply. It uses ASCII Command Interface over UART for communication with the target microcontroller, with additional functionality provided by the following pins on the mikroBUS™ line: PWM, INT, RST, CS. The RN4080 module from Microchip offers a complete solution to implement

Bluetooth 4.2 Low Energy connectivity. The host microcontroller can dynamically configure all products in the RN series with a few simple ASCII commands. The RN4870 supports peripheral and central Generic Access Profile (GAP) roles, actively scanning for other connectable devices instead of waiting for incoming connection requests. The peripherals are usually small, low-power devices that broadcast information to the central

device, like sensors and monitors. The central device can communicate with multiple peripherals. It also supports Remote Command mode, allowing a remote device to access Command mode remotely via Bluetooth. The module contains an integral ceramic chip antenna.

RN4870 Click hardware overview image

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and 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 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC v8 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-UART, USB DEVICE, and CAN 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 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC 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.

EasyPIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

3728

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Module Reset
RA0
RST
UART RTS
RA5
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
PWM Signal
RC1
PWM
UART CTS
RB1
INT
UART TX
RC6
TX
UART RX
RC7
RX
General-Purpose I/O
RC3
SCL
General-Purpose I/O
RC4
SDA
NC
NC
5V
Ground
GND
GND
2

Take a closer look

Schematic

RN4870 click Schematic schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

EasyPIC v8 front image hardware assembly
Rotary B 2 Click front image hardware assembly
MCU DIP 28 hardware assembly
EasyPIC v8 28pin-DIP - 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 DIP 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 RN4870 Click driver.

Key functions:

  • rn4870_read - This function gets message from 'void rn4870_receive function if flag was set

  • rn4870_receive - This function receives character by waits for '#' - character to start parsing message, waits for '*' - character to stop parsing message and sets flag if whole and properly formated message is received

  • rn4870_connect - This function connects to slave device with desired register address by secures the connection and entering data stream mode

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 Rn4870 Click example
 * 
 * # Description
 * This example reads and processes data from RN4870 clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes UART driver. Initializes device and parser.
 * 
 * ## Application Task  
 * If 'MASTER' - connects to 'SLAVE', sends message and disconnects. If 'SLAVE' - waits for connect request 
 * and message from 'MASTER' and LOGs received message.
 * 
 * ## Additional Function
 * - rn4870_process ( ) - The general process of collecting presponce 
 *                                   that sends a module.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rn4870.h"
#include "string.h"

#define PROCESS_COUNTER 10
#define PROCESS_RX_BUFFER_SIZE 500
#define PROCESS_PARSER_BUFFER_SIZE 500

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

// #define DEMO_APP_RECEIVER
#define DEMO_APP_TRANSMITER

static rn4870_t rn4870;
static log_t logger;

uint8_t RN4870_ADDR_MASTER[ 13 ] = {'D', 'F', '0', '0', '0', '0', '0', '6', '8', '7', '9', '0'};
uint8_t RN4870_ADDR_SLAVE[ 13 ] = {'D', 'F', '1', '1', '1', '1', '1', '6', '8', '7', '9', '0'};
uint8_t message_payload[ 17 ] = {'M', 'i', 'k', 'r', 'o', 'E', 'l', 'e', 'k', 't', 'r', 'o', 'n', 'i', 'k', 'a'};

uint8_t dev_type;
uint8_t receive_buffer[ 255 ];
uint8_t msg_flag = 0;
char *ptr;

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

static void rn4870_process ( void )
{
    int32_t rsp_size;
    
    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint8_t check_buf_cnt;
    

    rsp_size = rn4870_generic_read( &rn4870, &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++ )
        {
            rn4870_receive( &rn4870, uart_rx_buffer[ check_buf_cnt ] );
        }
    }
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    rn4870_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.

    rn4870_cfg_setup( &cfg );
    RN4870_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rn4870_init( &rn4870, &cfg );
    Delay_ms( 100 );
    
    dev_type = RN4870_DEVICETYPE_MASTER;

#ifdef DEMO_APP_TRANSMITER
    log_info( &logger, "RN4870 DEVICE TYPE MASTER" );
    rn4870_initialize( &rn4870, &RN4870_ADDR_MASTER[ 0 ] );
#endif
#ifdef DEMO_APP_RECEIVER
    log_info( &logger, "RN4870 DEVICE TYPE SLAVE" );
    rn4870_initialize( &rn4870, &RN4870_ADDR_SLAVE[ 0 ] );
    ptr = &receive_buffer[ 7 ];
#endif

    memset( &rn4870.device_buffer, 0, 255 );
    log_printf( &logger, " >>> app init done <<<  \r\n" );
}

void application_task ( void )
{
    rn4870_process(  );
#ifdef DEMO_APP_TRANSMITER
    rn4870_connect( &rn4870, &RN4870_ADDR_SLAVE[ 0 ] );
    Delay_ms( 100 );
    log_printf( &logger, ">>> sending data  <<<\r\n" );
    rn4870_send( &rn4870, RN4870_MTYPE_MSG, RN4870_DTYPE_STRING, RN4870_ID_MASTER, &message_payload[ 0 ] );
    Delay_ms( 100 );
    rn4870_disconnect( &rn4870 );
    Delay_ms( 100 );
#endif

#ifdef DEMO_APP_RECEIVER
    msg_flag = rn4870_read( &rn4870, &receive_buffer[ 0 ] );

    if ( msg_flag == 1 )
    {
        log_printf( &logger, ">>> data received <<<\r\n" );
        log_printf( &logger, ">>> data : " );
        log_printf( &logger, "%s\r\n", ptr );     
    }
#endif
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources