stm32实现SBUS传输

1. 基本配置

串口波特率：100k，9位数据位，偶校验，2位停止位，利用dma空闲中断进行接收数据和处理数据

接收函数

int8_t BSP_UART_IDLE_PollData(UART_HandleTypeDef *huart, struct RF207S_SBUS_DataStructure *rf207_sbus_data)
{

	int8_t nret = 0;
	if (Uart_Receive_Data.rxok == 0) //没有接收完就退出
	{
		nret = -1;

	}
	else
	{
		if (Uart_Receive_Data.rxlen < 25) //帧不完整
		{
			nret = -2;
		}
		else if (Uart_Receive_Data.rxbuf[0] != 0x0f || Uart_Receive_Data.rxbuf[24] != 0x00) //帧错误
		{
			nret = -3;
		}
		if (nret == 0)
		{
			//遥控器的取值范围：-100 ---->100 返回值的范围0----100
			// Min:354    Max:1696   ----->1342    chx-353/1342. == y*100
			rf207_sbus_data->ch1 = (((int16_t) Uart_Receive_Data.rxbuf[2] << 8) + ((int16_t) Uart_Receive_Data.rxbuf[1])) & 0x07ff;
			rf207_sbus_data->ch1 = (rf207_sbus_data->ch1-353)*100/1342.;
			rf207_sbus_data->ch2 = (((int16_t) Uart_Receive_Data.rxbuf[3] << 5) + ((int16_t) Uart_Receive_Data.rxbuf[2] >> 3))& 0x07ff;
			rf207_sbus_data->ch2 = (rf207_sbus_data->ch2-353)*100/1342.;
			rf207_sbus_data->ch3 = (((int16_t) Uart_Receive_Data.rxbuf[5] << 10) + ((int16_t) Uart_Receive_Data.rxbuf[4] << 2) + ((int16_t) Uart_Receive_Data.rxbuf[3] >> 6)) & 0x07ff;
			rf207_sbus_data->ch3 = (rf207_sbus_data->ch3-353)*100/1342.;
			rf207_sbus_data->ch4 = (((int16_t) Uart_Receive_Data.rxbuf[6] << 7) + ((int16_t) Uart_Receive_Data.rxbuf[5] >> 1))& 0x07ff;
			rf207_sbus_data->ch4 = (rf207_sbus_data->ch4-353)*100/1342.;
			rf207_sbus_data->ch5 =(((int16_t)Uart_Receive_Data.rxbuf[9]<<9) + ((int16_t)Uart_Receive_Data.rxbuf[8]<<1) + ((int16_t)buf[7]>>7)) & 0x07ff;
			rf207_sbus_data->ch5 = (rf207_sbus_data->ch5-353)*100/1342.;
			rf207_sbus_data->ch6 =(((int16_t)Uart_Receive_Data.rxbuf[10]<<6) + ((int16_t)Uart_Receive_Data.rxbuf[9]>>2)) & 0x07ff;
			rf207_sbus_data->ch6 = (rf207_sbus_data->ch6-353)*100/1342.;
			rf207_sbus_data->ch7 =(((int16_t)Uart_Receive_Data.rxbuf[11]<<3) + ((int16_t)Uart_Receive_Data.rxbuf[10]>>5)) & 0x07ff;
			rf207_sbus_data->ch7 = (rf207_sbus_data->ch7-353)*100/1342.;
			rf207_sbus_data->ch8 =(((int16_t)Uart_Receive_Data.rxbuf[13]<<8) + (int16_t)Uart_Receive_Data.rxbuf[12]) & 0x07ff;
			rf207_sbus_data->ch8 = (rf207_sbus_data->ch8-353)*100/1342.;
			rf207_sbus_data->ch9 =(((int16_t)Uart_Receive_Data.rxbuf[14]<<5) + ((int16_t)Uart_Receive_Data.rxbuf[13]>>3)) & 0x07ff;
			rf207_sbus_data->ch9 = (rf207_sbus_data->ch9-353)*100/1342.;
			rf207_sbus_data->ch10 =(((int16_t)Uart_Receive_Data.rxbuf[16]<<10) + ((int16_t)Uart_Receive_Data.rxbuf[15]<<2) + ((int16_t)Uart_Receive_Data.rxbuf[14]>>6)) & 0x07ff;
			rf207_sbus_data->ch10 = (rf207_sbus_data->ch10-353)*100/1342.;
		}
		Uart_Receive_Data.rxok = 0;
		__HAL_UART_ENABLE_IT(huart, UART_IT_IDLE); //使能串口空闲中断
		memset(Uart_Receive_Data.rxbuf, 0, UART_RECEIVE_IDLE_RX_MAXLEN);
		HAL_UART_Receive_DMA(huart, Uart_Receive_Data.rxbuf, UART_RECEIVE_IDLE_RX_MAXLEN); //开启串口DMA接收
	}

	return nret;
}

空闲中断函数(将函数放在默认的空闲中断之前)记得在it中断文件中包含该函数的头文件

void BSP_UART_IDLE_CallBack(UART_HandleTypeDef *huart)
{
	if ((__HAL_UART_GET_FLAG(huart, UART_FLAG_IDLE) != RESET))
	{
		HAL_UART_DMAStop(huart);
		__HAL_UART_CLEAR_IDLEFLAG(huart);
		Uart_Receive_Data.rxlen = UART_RECEIVE_IDLE_RX_MAXLEN - __HAL_DMA_GET_COUNTER(huart->hdmarx);
		Uart_Receive_Data.rxok = 1;
	}
}

避坑指南：

用串口调试sbus：

串口用的是小端模式，是低位先发，刚好sbus一个通道的值是16位，所以在串口里显示的应该是两个16进制的数，后面的16进制数是高位，

建议直接用调试直接看内存数据