Intermediate
30 min

Tailor-made Bluetooth solution with WT41u and PIC18F57Q43

Wireless wonders at your fingertips

Bluetooth 2 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

Bluetooth 2 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Ready to revolutionize your automotive diagnostics unit? Add this Bluetooth solution now!

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Hardware Overview

How does it work?

Bluetooth 2 Click is based on the WT41u, a fully integrated Bluetooth 2.1 + EDR, Class 1 module from Silicon Labs. Combining an onboard chip antenna, Bluetooth radio, and an onboard iWRAP Bluetooth Stack, the WT41u provides a superior link budget and 650-meter line-of-sight connectivity for Bluetooth applications with extreme radio performance or required reliability. Thanks to Bluegiga's iWRAP Bluetooth stack, the WT41u implements 13 different Bluetooth profiles and Apple iAP connectivity ensuring quick time-to-market. This Click board™ represents an ideal solution for rapidly integrating high-performing Bluetooth wireless technology without investing

several months in Bluetooth radio and stack development. The WT41u communicates with MCU using the UART interface, RS232 protocol, with commonly used UART RX, TX, and hardware flow control pins UART CTS and RTS. The UART configuration parameters, such as data rate and packet format, are set using WT41u software. In addition to the UART interface, an SPI interface is available, but only for system debugging. The WT41u uses 16-bit data and a 16-bit address serial peripheral interface to program the Flash memory and set the PSKEY configurations. The CS pin has a dual function, as the CS pin of the SPI interface or CTS for UART, can be

selected by moving the SMD jumper designated as COM SEL to an appropriate position. Besides the commonly used interface pins, Bluetooth 2 Click also has a general reset and bidirectional digital/analog I/O pins routed to the RST, PWM, and AN pins of the mikroBUS™ socket, respectively. 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. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

Bluetooth 2 Click top side image
Bluetooth 2 Click lateral side image
Bluetooth 2 Click bottom side 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

Analog Signal
PA0
AN
Reset
PA7
RST
Chip Select
PD4
CS
SPI Clock
PC6
SCK
SPI Data OUT
PC5
MISO
SPI Data IN
PC4
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
General Purpose I/O
PB0
PWM
UART RTS
PA6
INT
UART TX
PC2
TX
UART RX
PC3
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Bluetooth 2 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

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Bluetooth 2 Click driver.

Key functions:

  • bluetooth2_factory_reset - This function factory resets the device

  • bluetooth2_set_device_name - This function sets the local device name

  • bluetooth2_generic_write - This function writes a desired number of data bytes by using UART serial interface

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 Bluetooth 2 Click Example.
 *
 * # Description
 * This example reads and processes data from Bluetooth 2 clicks.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver, then performs a factory reset, removes all pairings, and
 * sets the local device name.
 *
 * ## Application Task
 * Logs all the received messages/responses on the USB UART, and if there's any device
 * connected to the click board the module sends a desired message every 5 seconds back to it.
 *
 * ## Additional Function
 * - static void bluetooth2_clear_app_buf ( void )
 * - static err_t bluetooth2_process ( void )
 * - static err_t bluetooth2_display_rsp ( uint16_t timeout )
 *
 * @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 Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "bluetooth2.h"

#define PROCESS_BUFFER_SIZE 200

#define RSP_OK              "OK."
#define RSP_READY           "READY."
#define RSP_RING            "RING"
#define RSP_NO_CARRIER      "NO CARRIER"

// Local device name.
#define DEVICE_NAME         "Bluetooth 2 Click"

// Message which will be sent to the connected device.
#define TEXT_TO_SEND        "MikroE - Bluetooth 2 click\r\n" 

// Text sending frequency in miliseconds.
#define SENDING_FREQ        5000  

static bluetooth2_t bluetooth2;
static log_t logger;

static char app_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
static int32_t app_buf_cnt = 0;
static uint8_t connection_flag = 0;
static uint16_t send_cnt = 0;

/**
 * @brief Bluetooth 2 clearing application buffer.
 * @details This function clears memory of application buffer and reset its length and counter.
 * @note None.
 */
static void bluetooth2_clear_app_buf ( void );

/**
 * @brief Bluetooth 2 data reading function.
 * @details This function reads data from device and concatenates data to application buffer.
 *
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 *         @li @c -2 - Application buffer overflow.
 *
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t bluetooth2_process ( void );

/**
 * @brief Bluetooth 2 display response function.
 * @details This function reads data from device until it sends OK or READY message or until
 * it exceeds the timeout value.
 * @param[in] timeout : Timeout value in miliseconds.
 *
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 *
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t bluetooth2_display_rsp ( uint16_t timeout );

void application_init ( void ) 
{
    log_cfg_t log_cfg;                /**< Logger config object. */
    bluetooth2_cfg_t bluetooth2_cfg;  /**< Click config object. */

    /** 
     * 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 );
    Delay_ms( 100 );
    log_info( &logger, " Application Init " );

    // Click initialization.

    bluetooth2_cfg_setup( &bluetooth2_cfg );
    BLUETOOTH2_MAP_MIKROBUS( bluetooth2_cfg, MIKROBUS_1 );
    err_t init_flag  = bluetooth2_init( &bluetooth2, &bluetooth2_cfg );
    if ( UART_ERROR == init_flag ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    bluetooth2_default_cfg ( &bluetooth2 );
    bluetooth2_process( );
    bluetooth2_clear_app_buf( );
    
    log_printf( &logger, " - Factory Reset -\r\n" );
    bluetooth2_factory_reset ( &bluetooth2 );
    bluetooth2_display_rsp ( 2000 ); 
    
    log_printf( &logger, " - Enable OK response -\r\n" );
    bluetooth2_enable_ok_response ( &bluetooth2 );
    bluetooth2_display_rsp ( 1000 ); 
    
    log_printf( &logger, " - Remove Pairings -\r\n" );
    bluetooth2_remove_pairings ( &bluetooth2 );
    bluetooth2_display_rsp ( 1000 ); 
    
    log_printf( &logger, " - Set Device Name -\r\n" );
    bluetooth2_set_device_name ( &bluetooth2, DEVICE_NAME );
    bluetooth2_display_rsp ( 1000 ); 
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    bluetooth2_process();
    if ( app_buf_len > 0 ) 
    {
        Delay_ms( 200 );
        bluetooth2_process();
        
        if ( strstr( app_buf, RSP_RING ) )
        {
            connection_flag = 1;
            send_cnt = 0;
        }
        if ( strstr( app_buf, RSP_NO_CARRIER ) )
        {
            connection_flag = 0;
            send_cnt = 0;
        }
        log_printf( &logger, "%s", app_buf );
        bluetooth2_clear_app_buf(  );
    }
    
    if ( connection_flag == 1 && send_cnt++ > SENDING_FREQ )
    {
        bluetooth2_generic_write( &bluetooth2, TEXT_TO_SEND, strlen( TEXT_TO_SEND ) );
        send_cnt = 0;
    }
    
    Delay_ms( 1 );
}

void main ( void ) 
{
    application_init( );

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

static void bluetooth2_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
    app_buf_cnt = 0;
}

static err_t bluetooth2_process ( void ) 
{
    int32_t rx_size;
    char rx_buff[ PROCESS_BUFFER_SIZE ] = { 0 };

    rx_size = bluetooth2_generic_read( &bluetooth2, rx_buff, PROCESS_BUFFER_SIZE );

    if ( rx_size > 0 ) 
    {
        int32_t buf_cnt = 0;

        if ( app_buf_len + rx_size >= PROCESS_BUFFER_SIZE ) 
        {
            bluetooth2_clear_app_buf(  );
            return BLUETOOTH2_ERROR;
        } 
        else 
        {
            buf_cnt = app_buf_len;
            app_buf_len += rx_size;
        }

        for ( int32_t rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) 
        {
            if ( rx_buff[ rx_cnt ] != 0 ) 
            {
                app_buf[ ( buf_cnt + rx_cnt ) ] = rx_buff[ rx_cnt ];
            }
            else
            {
                app_buf_len--;
                buf_cnt--;
            }

        }
        return BLUETOOTH2_OK;
    }
    return BLUETOOTH2_ERROR;
}

static err_t bluetooth2_display_rsp ( uint16_t timeout )
{
    uint16_t timeout_cnt = 0;
    
    bluetooth2_process(  );
    
    while ( ( strstr( app_buf, RSP_OK ) == 0 ) && ( strstr( app_buf, RSP_READY ) == 0 ) && timeout_cnt++ < timeout )
    {
        bluetooth2_process(  );
        Delay_ms( 1 );
    }
    
    if ( app_buf_len > 0 )
    {
        for ( int32_t buf_cnt = 0; buf_cnt < app_buf_len; buf_cnt++ )
        {
            log_printf( &logger, "%c", app_buf[ buf_cnt ] );
        }
        bluetooth2_clear_app_buf(  );
        log_printf( &logger, "--------------------------------\r\n" );
        return BLUETOOTH2_OK;
    }
    return BLUETOOTH2_ERROR;
}

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

Additional Support

Resources

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