使用 RFM75 和 PIC18F25K40 建立长距离无线传输

轻松保持连接

已发布 6月 24, 2024

点击板

ISM Click

开发板

EasyPIC v8

编译器

NECTO Studio

微控制器单元

PIC18F25K40

释放您解决方案的潜力，实现高效、快速和可靠的无线通信。

硬件概览

它是如何工作的？

ISM Click基于RF Solutions的RFM75，这是一款低功耗、高性能的2.4GHz GFSK收发器，工作在全球ISM频段2400MHz至2527MHz。RFM75以TDD模式运行，可作为发射机或接收机。突发模式传输和高达2Mbps的空中数据速率使其适用于超低功耗应用。嵌入式数据包处理引擎使得整个操作只需一个简单的MCU作为无线电系统。自动重传和自动确认功能可在没有任何MCU干预的情况下提供可靠的链路。发射机和接收机必须使用相同的RF信道频率进行通信，支持可编程的空中数据速率为250Kbps、1Mbps或2Mbps。RF信道频率

决定了RFM75使用的信道的中心。RF_CH寄存器在寄存器组0中设置频率，按照以下公式计算F0= 2400 + RF_CH（MHz），其中RF信道频率的分辨率为1MHz。ISM Click通过标准SPI串行接口与MCU通信，该接口的工作时钟速率可高达8 MHz。在省电模式下，RFM75处于睡眠模式，功耗极低。在此模式下，SPI接口仍然活动，通过SPI接口可访问所有寄存器值。此外，此Click板上还有一个黄色LED指示灯，路由到mikroBUS™插座的INT引脚上（在成功接收数据包后为用户提供反馈），以及一个芯片使能功能，路由到mikroBUS™插座

的RST引脚上，用于激活RFM75的TX或RX模式。此外，它还有两个额外的LED指示灯，一个红色和一个蓝色LED，路由到mikroBUS™插座的AN和PWM引脚上。用户可以在发送或接收数据时使用它进行可视指示。此Click板™只能使用3.3V逻辑电压电平操作。在使用具有不同逻辑电平的MCU之前，必须对板上执行适当的逻辑电压电平转换。但是，该Click板™配备了一个包含函数和示例代码的库，可用作进一步开发的参考。

功能概述

开发板

EasyPIC v8 是一款专为快速开发嵌入式应用的需求而特别设计的开发板。它支持许多高引脚计数的8位PIC微控制器，来自Microchip，无论它们的引脚数量如何，并且具有一系列独特功能，例如首次集成的调试器/程序员。开发板布局合理，设计周到，使得最终用户可以在一个地方找到所有必要的元素，如开关、按钮、指示灯、连接器等。得益于创新的制造技术，EasyPIC v8 提供了流畅而沉浸式的工作体验，允许在任何情况下、任何地方、任何时候都能访问。

EasyPIC v8 开发板的每个部分都包含了使同一板块运行最高效的必要组件。除了先进的集成CODEGRIP程序/调试模块，该模块提供许多有价值的编程/调试选项和与Mikroe软件环境的无缝集成外，该板还包括一个干净且调节过的开发板电源供应模块。它可以使用广泛的外部电源，包括电池、外部12V电源供应和通过USB Type-C（USB-C）连接器的电源。通信选项如USB-UART、USB DEVICE和CAN也包括在内，包括广受好评的mikroBUS™标准、两种显示选项（图形和

基于字符的LCD）和几种不同的DIP插座。这些插座覆盖了从最小的只有八个至四十个引脚的8位PIC MCU的广泛范围。EasyPIC v8 是Mikroe快速开发生态系统的一个组成部分。它由Mikroe软件工具原生支持，得益于大量不同的Click板™（超过一千块板），其数量每天都在增长，它涵盖了原型制作和开发的许多方面。

微控制器概述

MCU卡片 / MCU

建筑

PIC

MCU 内存 (KB)

硅供应商

Microchip

引脚数

RAM (字节)

2048

使用的MCU引脚

mikroBUS™映射器

Data Transmission Indicator

RA3

Chip Enable

RA0

RST

SPI Chip Select

RA5

SPI Clock

RC3

SCK

SPI Data OUT

RC4

MISO

SPI Data IN

RC5

MOSI

Power Supply

3.3V

Ground

GND

Data Reception Indicator

RC1

PWM

Interrupt

RB1

INT

SCL

SDA

Ground

GND

“仔细看看！”

Click board™ 原理图

一步一步来

项目组装

EasyPIC v8 front image hardware assembly

从选择您的开发板和Click板™开始。以EasyPIC v8作为您的开发板开始。

GNSS2 Click front image hardware assembly

EasyPIC v8 Access DIPMB 1 - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

NECTO Output Selection Step Image hardware assembly

Necto DIP image step 7 hardware assembly

实时跟踪您的结果

应用程序输出

1. 应用程序输出 - 在调试模式下，“应用程序输出”窗口支持实时数据监控，直接提供执行结果的可视化。请按照提供的教程正确配置环境，以确保数据正确显示。

2. UART 终端 - 使用UART Terminal通过USB to UART converter监视数据传输，实现Click board™与开发系统之间的直接通信。请根据项目需求配置波特率和其他串行设置，以确保正常运行。有关分步设置说明，请参考提供的教程。

3. Plot 输出 - Plot功能提供了一种强大的方式来可视化实时传感器数据，使趋势分析、调试和多个数据点的对比变得更加直观。要正确设置，请按照提供的教程，其中包含使用Plot功能显示Click board™读数的分步示例。在代码中使用Plot功能时，请使用以下函数：plot(insert_graph_name, variable_name);。这是一个通用格式，用户需要将“insert_graph_name”替换为实际图表名称，并将“variable_name”替换为要显示的参数。

软件支持

库描述

该库包含 ISM Click 驱动程序的 API。

关键功能:

ism_cfg_setup - 配置对象初始化函数。
ism_init - 初始化函数。
ism_default_cfg - Click 默认配置函数。

开源

代码示例

完整的应用程序代码和一个现成的项目可以通过NECTO Studio包管理器直接安装到NECTO Studio。应用程序代码也可以在MIKROE的GitHub账户中找到。

/*!
 * @file main.c
 * @brief Ism Click example
 *
 * # Description
 * This library contains API for the ISM Click driver.
 * This example transmits/receives and processes data from ISM clicks.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes driver and performs the default configuration. 
 *
 * ## Application Task
 * Transmitter/Receiver task depends on uncommented code.
 * Receiver logging each received byte to the UART for data logging,
 * while transmitter send messages every 1 second.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ism.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

static ism_t ism;
static log_t logger;

static uint8_t demo_message_1[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13, 10, 0 };
static uint8_t demo_message_2[ 12 ] = { 'I', 'S', 'M', ' ', 'C', 'l', 'i', 'c', 'k', 13, 10, 0 };

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ism_cfg_t ism_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 );
    log_info( &logger, " Application Init " );

    // Click initialization.
    ism_cfg_setup( &ism_cfg );
    ISM_MAP_MIKROBUS( ism_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == ism_init( &ism, &ism_cfg ) ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    }

    ism_default_cfg ( &ism );
    Delay_ms ( 100 );
    
#ifdef DEMO_APP_TRANSMITTER
    ism_switch_tx_mode( &ism );
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    ism_switch_rx_mode( &ism );
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    ism_transmit_packet( &ism, ISM_CMD_W_TX_PAYLOAD_NOACK, demo_message_1, 9 );
    log_printf( &logger, "  Tx : %s", demo_message_1 );
    Delay_ms ( 1000 );

    ism_transmit_packet( &ism, ISM_CMD_W_TX_PAYLOAD_NOACK, demo_message_2, 12 );
    log_printf( &logger, "  Tx : %s", demo_message_2 );
    Delay_ms ( 1000 );
#else
    uint8_t rx_buf[ ISM_MAX_PACKET_LEN ] = { 0 };

    ism_receive_packet( &ism, &rx_buf[ 0 ] );

    if ( rx_buf[ 0 ] ) 
    {
        log_printf( &logger, "  Rx : %s", rx_buf );
    }
#endif
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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

/*!
 * @file main.c
 * @brief Ism Click example
 *
 * # Description
 * This library contains API for the ISM Click driver.
 * This example transmits/receives and processes data from ISM clicks.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes driver and performs the default configuration. 
 *
 * ## Application Task
 * Transmitter/Receiver task depends on uncommented code.
 * Receiver logging each received byte to the UART for data logging,
 * while transmitter send messages every 1 second.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ism.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

static ism_t ism;
static log_t logger;

static uint8_t demo_message_1[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13, 10, 0 };
static uint8_t demo_message_2[ 12 ] = { 'I', 'S', 'M', ' ', 'C', 'l', 'i', 'c', 'k', 13, 10, 0 };

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ism_cfg_t ism_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 );
    log_info( &logger, " Application Init " );

    // Click initialization.
    ism_cfg_setup( &ism_cfg );
    ISM_MAP_MIKROBUS( ism_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == ism_init( &ism, &ism_cfg ) ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    }

    ism_default_cfg ( &ism );
    Delay_ms ( 100 );
    
#ifdef DEMO_APP_TRANSMITTER
    ism_switch_tx_mode( &ism );
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    ism_switch_rx_mode( &ism );
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    ism_transmit_packet( &ism, ISM_CMD_W_TX_PAYLOAD_NOACK, demo_message_1, 9 );
    log_printf( &logger, "  Tx : %s", demo_message_1 );
    Delay_ms ( 1000 );

    ism_transmit_packet( &ism, ISM_CMD_W_TX_PAYLOAD_NOACK, demo_message_2, 12 );
    log_printf( &logger, "  Tx : %s", demo_message_2 );
    Delay_ms ( 1000 );
#else
    uint8_t rx_buf[ ISM_MAX_PACKET_LEN ] = { 0 };

    ism_receive_packet( &ism, &rx_buf[ 0 ] );

    if ( rx_buf[ 0 ] ) 
    {
        log_printf( &logger, "  Rx : %s", rx_buf );
    }
#endif
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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

/*!
 * @file main.c
 * @brief Ism Click example
 *
 * # Description
 * This library contains API for the ISM Click driver.
 * This example transmits/receives and processes data from ISM clicks.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes driver and performs the default configuration. 
 *
 * ## Application Task
 * Transmitter/Receiver task depends on uncommented code.
 * Receiver logging each received byte to the UART for data logging,
 * while transmitter send messages every 1 second.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ism.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

static ism_t ism;
static log_t logger;

static uint8_t demo_message_1[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13, 10, 0 };
static uint8_t demo_message_2[ 12 ] = { 'I', 'S', 'M', ' ', 'C', 'l', 'i', 'c', 'k', 13, 10, 0 };

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ism_cfg_t ism_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 );
    log_info( &logger, " Application Init " );

    // Click initialization.
    ism_cfg_setup( &ism_cfg );
    ISM_MAP_MIKROBUS( ism_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == ism_init( &ism, &ism_cfg ) ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    }

    ism_default_cfg ( &ism );
    Delay_ms ( 100 );
    
#ifdef DEMO_APP_TRANSMITTER
    ism_switch_tx_mode( &ism );
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    ism_switch_rx_mode( &ism );
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    ism_transmit_packet( &ism, ISM_CMD_W_TX_PAYLOAD_NOACK, demo_message_1, 9 );
    log_printf( &logger, "  Tx : %s", demo_message_1 );
    Delay_ms ( 1000 );

    ism_transmit_packet( &ism, ISM_CMD_W_TX_PAYLOAD_NOACK, demo_message_2, 12 );
    log_printf( &logger, "  Tx : %s", demo_message_2 );
    Delay_ms ( 1000 );
#else
    uint8_t rx_buf[ ISM_MAX_PACKET_LEN ] = { 0 };

    ism_receive_packet( &ism, &rx_buf[ 0 ] );

    if ( rx_buf[ 0 ] ) 
    {
        log_printf( &logger, "  Rx : %s", rx_buf );
    }
#endif
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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