求助大神，stm32和sim900通信不正常，发什么接收什么，没有OK~~~!!!!!

skyboy_23 · 发表于 2014-5-30 14:49:58

我用USART2和sim900连接，接线没有问题，现在的情况是，我在测试其功能时发送"ATE1"，只是返回了"ATE1",正常值应该返回"ATE1 OK ",我给出主要代码，大家帮我看看

我的USART3连接GPS , USART2连接sim900， USART1连接上位机

如下是串口的中断部分：

[mw_shl_code=c,true]void NVIC_Configuration(void) { NVIC_InitTypeDef NVIC_InitStructure; NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn; //通道设置为串口3中断 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //中断响应先占式优先级为2 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; //中断响应从优先级0 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn; //通道设置为串口2中断 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //中断响应先占式优先级为1 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //中断响应从优先级0 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); NVIC_InitStructure.NVIC_IRQChannel = WWDG_IRQn; //使能窗口定时器中断 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占式优先级为0 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); }[/mw_shl_code]

USART2的中断程序

[mw_shl_code=c,true]void USART2_IRQHandler(void) { u8 i,j,k = 0; if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)//判断是否是接收中断 { //USART_ClearITPendingBit(USART2,USART_IT_RXNE);//清除接收中断位 GsmRcv[GsmRcvCnt] = USART_ReceiveData(USART2); GsmRcvCnt++; //j = strlen(GsmRcv); //delay_nms(50); //k = strlen(GsmRcv); printf("已进入串口2中断"); if(GsmRcvCnt >= 99) { GsmRcvCnt = 0; } if(GsmRcv[GsmRcvCnt-1] == 0x0A && GsmRcv[GsmRcvCnt-2] == 0x0D && GsmRcvCnt >=2 ) { printf("接收完毕"); USART_ITConfig(USART2,USART_IT_RXNE,DISABLE); //关闭USART2接收中断 gsm_num = GsmRcvCnt; printf("给gsm_num赋值"); GsmRcvCnt = 0; GsmAtFlag = 1; i = 0; while(GsmRcv != 0) { gsm_datas = GsmRcv; GsmRcv = 0; i++; printf("gsm_datas已有数据"); } printf("gsm_num: %d\n",strlen(gsm_datas)); for(i=0;i<99;i++) { printf("%c",gsm_datas); } //USART_ITConfig(USART2,USART_IT_RXNE,ENABLE); } } } [/mw_shl_code]

[mw_shl_code=c,true]u8 GPRSConnect(void) { u8 err=0; printf("进入GPRS"); SendAT("ATE1",4); printf("已发送ate1"); err=WaitForStr("OK",2,2); //ATE1 OK printf("已发送AT"); if(err == 0) { printf("ATE1 OK"); } if(err>0) return err; return err; } [/mw_shl_code]

[mw_shl_code=c,true]//发送AT指令 void SendAT(u8 *dat,u16 num) { USART2_Write(dat,num); USART2_SendByte(0x0D); USART2_SendByte(0x0A); }[/mw_shl_code]