Intermediate
30 min

Create an easy-to-use/drop-in solution based on BLE 4.2 with RN4870 and PIC32MX675F256L

Simplify connectivity

RN4870 click with Fusion for PIC v8

Published Jul 27, 2023

Click board™

RN4870 click

Dev. board

Fusion for PIC v8

Compiler

NECTO Studio

MCU

PIC32MX675F256L

Enable Bluetooth Low Energy connectivity for data exchange between devices.

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

Fusion for PIC 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 PIC, dsPIC, PIC24, and PIC32 MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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 PIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the Fusion for PIC 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

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet are also included, including the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options (graphical and character-based LCD). Fusion for PIC 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 PIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

PIC32

MCU Memory (KB)

256

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

65536

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Module Reset
PB0
RST
UART RTS
PD7
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
PWM Signal
PD1
PWM
UART CTS
PE8
INT
UART TX
PF13
TX
UART RX
PF12
RX
General-Purpose I/O
PA2
SCL
General-Purpose I/O
PA3
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

RN4870 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 PIC v8 as your development board.

Fusion for PIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN 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

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 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

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 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

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