用STM32F103C8T6单片机编写一套基于gsm收发短信控制继电器的程序

以下是使用STM32F103C8T6单片机编写基于GSM收发短信控制继电器的简单示例程序：

#include "stm32f10x.h"
#include "stdio.h"
#include "string.h"

#define USART1_BAUDRATE 9600

void USART1_Init()
{
    GPIO_InitTypeDef GPIO_InitStruct;
    USART_InitTypeDef USART_InitStruct;
    
    // Enable GPIOA and USART1 clocks
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
    
    // Configure USART1 TX pin (PA9) as alternate function push-pull
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStruct);
    
    // Configure USART1 RX pin (PA10) as input floating
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStruct);
    
    // Configure USART1
    USART_InitStruct.USART_BaudRate = USART1_BAUDRATE;
    USART_InitStruct.USART_WordLength = USART_WordLength_8b;
    USART_InitStruct.USART_StopBits = USART_StopBits_1;
    USART_InitStruct.USART_Parity = USART_Parity_No;
    USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART1, &USART_InitStruct);
    
    // Enable USART1
    USART_Cmd(USART1, ENABLE);
}

void GSM_SendCommand(char* command)
{
    while (*command)
    {
        USART_SendData(USART1, *command++);
        while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
    }
}

void GSM_Init()
{
    // Configure GSM module baudrate
    GSM_SendCommand("AT+IPR=9600\r\n");
    delay_ms(100);
    
    // Set GSM module to text mode
    GSM_SendCommand("AT+CMGF=1\r\n");
    delay_ms(100);
}

void GSM_SendSMS(char* phoneNumber, char* message)
{
    char command[50];
    
    // Set phone number
    sprintf(command, "AT+CMGS=\"%s\"\r\n", phoneNumber);
    GSM_SendCommand(command);
    delay_ms(100);
    
    // Set message content
    GSM_SendCommand(message);
    delay_ms(100);
    
    // Send message
    USART_SendData(USART1, 0x1A);
    while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
    delay_ms(1000);
}

int main(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
    
    GPIO_InitTypeDef GPIO_InitStruct;
    
    // Configure GPIOC Pin 13 as output push-pull
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_13;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOC, &GPIO_InitStruct);
    
    USART1_Init();
    GSM_Init();
    
    while (1)
    {
        // Check for new SMS
        GSM_SendCommand("AT+CMGL=\"REC UNREAD\"\r\n");
        delay_ms(2000);
        
        // Process received SMS
        // ...
        
        // Control the relay based on the received SMS
        // Example: If the received SMS is "ON", turn on the relay
        //          If the received SMS is "OFF", turn off the relay
        // ...
    }
}

请注意，上述代码仅为示例，可能需要根据您的具体硬件和电路连接进行适当修改。同时，GSM模块的具体型号和AT指令也需要根据实际情况进行相应的调整。此外，您可能还需要实现一个延时函数 `delay_ms()` 来提供延时功能。