Arduino stm32 USB CDC虚拟串口使用示例

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• 📍相关篇《STM32F401RCT6基于Arduino框架点灯程序》
• 🔖本开发环境基于VSCode + PIO
• 🌿验证芯片：STM32F401RC
• ⌛USB CDC引脚： PA11、 PA12
• 🔧platformio.ini配置信息：

[env:genericSTM32F401RC]
platform = ststm32
board = genericSTM32F401RC
framework = arduino
build_flags = -D USBCON -D USBD_USE_CDC;           -D USE_USB_HS
upload_protocol = stlink
;upload_protocol = serial
;upload_protocol = jlink
;upload_protocol = cmsis-dap

• 🧨 STM32 USB CDC虚拟串口在Arduino IDE中好像可以在功能菜单上选择，由于IDE环境支持包没有安装，没有进一步验证。 ✨个人还是推荐VSCode + PIO 方式来开发，比较灵活和便捷。✨

🔨Arduino IDE 环境下配置USB CDC虚拟串口方法

• 🔖这里以Arduino IDE 2.2.1版本设置为例，进行USB CDC虚拟串口配置：
  

📗USBSerial API相关函数

• 🔖 基本功能函数和硬件串口相关功能函数是一样。

    void begin(void);void begin(uint32_t);void begin(uint32_t, uint8_t);void end(void);virtual int available(void);virtual int availableForWrite(void);virtual int peek(void);virtual int read(void);virtual size_t readBytes(char *buffer, size_t length);  // read chars from stream into buffervirtual size_t readBytesUntil(char terminator, char *buffer, size_t length);  // as readBytes with terminator charactervirtual void flush(void);virtual size_t write(uint8_t);virtual size_t write(const uint8_t *buffer, size_t size);

• ✨ 为什么是使用Serial,因为在WSerial.h文件中有如下定义：

#if defined (USBCON) && defined(USBD_USE_CDC)#ifndef DISABLE_GENERIC_SERIALUSB#define ENABLE_SERIALUSB#if !defined(Serial)#define Serial SerialUSB#define serialEvent serialEventUSB#endif#endif#if defined(ENABLE_SERIALUSB)#define HAVE_SERIALUSB#endif

📝示例代码

#include <Arduino.h>
//#include <HardwareSerial.h>
#include <USBSerial.h>
//HardwareSerial Serial2(USART2); // 创建一个Serial2对象
//Arduino IDE环境下需要启用下面2个宏
// #define USBCON  1
// #define USBD_USE_CDC 1//----------
// #define USB_CDC_HID 1// put function declarations here:
int myFunction(int, int);#define led1 PC13
#define led2 PA_5uint32_t TimerUART;//HardwareSerial Serial1(PA10, PA9);//RX,TX将Serialx(x=1-4)串口x的管脚指定到PA10，PA9引脚上//USBSerial SerialCDC; // 创建一个USBSerial对象
//  the setup function runs once when you press reset or power the board
void setup()
{// Serial1.begin(115200);  // 初始化串口1作为调试串口// Serial.begin(115200); // Serial = Serial2初始化串口2作为调试信息输出// Serial.begin(115200);Serial.begin();// initialize digital pin LED_BUILTIN as an output.// Serial1.setRx(PA10); // using pin name PY_n// Serial1.setTx(PA9); // using pin number PYn// Serial.begin(115200);pinMode(led1, OUTPUT);pinMode(led2, OUTPUT);// pinMode(LED_BUILTIN, OUTPUT);TimerUART = HAL_GetTick();
}// the loop function runs over and over again forever
void loop()
{if ((HAL_GetTick() - TimerUART) > 1000){digitalToggle(led1);digitalToggle(led2);Serial.println("USART2(PA2 PA3)Arduino STM32F401RC \n");// delay(500); // wait for a secondSerial.printf("USART1(PA9 PA10)STM32F401 SysClockFreq:%d \r\n", HAL_RCC_GetSysClockFreq());Serial.print("from SerialUSB data\n");TimerUART = HAL_GetTick();}
}// put function definitions here:
int myFunction(int x, int y)
{return x + y;
}

• 🌿输出效果：