memset(&PM_Sensor_Data,0,(sizeof(PM_Sensor_Data) - 2));

这是一个使用 memset 函数对 PM_Sensor_Data 变量进行清零操作的语句。其中，memset 函数的第一个参数是要操作的目标变量的指针，第二个参数是要设置的值，第三个参数是要设置的字节数。这里的 sizeof(PM_Sensor_Data) - 2 表示要清零的字节数为 PM_Sensor_Data 变量所占用的字节数减去 2。具体含义需要结合上下文来理解。

相关问题

void PMSensor_DataReflash(void) // PM传感器数据回流函数 解析函数 ￥￥重要函数￥￥ { uint16_t Buffer_Len; //缓冲区长度 memset(&PM_Sensor_Data,0,(sizeof(PM_Sensor_Data) - 2)); //PM_Sensor_Data.PM2_5_Old should not set to zero Buffer_Len = (uint16_t)((PM_Sensor_RxBuffer[2] << 8) | PM_Sensor_RxBuffer[3]); if(Buffer_Len == 28) //PMS1003/5003 { PM_Sensor_Data.Buffer_Len = 28; PM_Sensor_Data.PM1_0_CF = (uint16_t)((PM_Sensor_RxBuffer[4]<<8) | PM_Sensor_RxBuffer[5]); PM_Sensor_Data.PM2_5_CF = (uint16_t)((PM_Sensor_RxBuffer[6]<<8) | PM_Sensor_RxBuffer[7]); PM_Sensor_Data.PM10_CF = (uint16_t)((PM_Sensor_RxBuffer[8]<<8) | PM_Sensor_RxBuffer[9]); PM_Sensor_Data.PM1_0 = (uint16_t)((PM_Sensor_RxBuffer[10]<<8) | PM_Sensor_RxBuffer[11]); PM_Sensor_Data.PM2_5 = (uint16_t)((PM_Sensor_RxBuffer[12]<<8) | PM_Sensor_RxBuffer[13]); PM_Sensor_Data.PM10 = (uint16_t)((PM_Sensor_RxBuffer[14]<<8) | PM_Sensor_RxBuffer[15]); PM_Sensor_Data.Count0_3nm = (uint16_t)((PM_Sensor_RxBuffer[16]<<8) | PM_Sensor_RxBuffer[17]); PM_Sensor_Data.Count0_5nm = (uint16_t)((PM_Sensor_RxBuffer[18]<<8) | PM_Sensor_RxBuffer[19]); PM_Sensor_Data.Count1_0nm = (uint16_t)((PM_Sensor_RxBuffer[20]<<8) | PM_Sensor_RxBuffer[21]); PM_Sensor_Data.Count2_5nm = (uint16_t)((PM_Sensor_RxBuffer[22]<<8) | PM_Sensor_RxBuffer[23]); PM_Sensor_Data.Count5_0nm = (uint16_t)((PM_Sensor_RxBuffer[24]<<8) | PM_Sensor_RxBuffer[25]); PM_Sensor_Data.Count10nm = (uint16_t)((PM_Sensor_RxBuffer[26]<<8) | PM_Sensor_RxBuffer[27]); }

这是一个函数的具体实现，该函数的作用是解析从PM传感器接收到的数据，并将解析后的数据存储在PM_Sensor_Data结构体中。该函数首先将PM_Sensor_Data结构体中除了PM_Sensor_Data.PM2_5_Old之外的所有成员清零，然后根据接收到的数据长度(Buffer_Len)判断传感器类型，如果是PMS1003/5003，则将接收到的数据解析并存储在PM_Sensor_Data结构体中。具体来说，该函数将接收到的数据中每个数据点的数值提取出来，并存储在PM_Sensor_Data结构体的相应成员中。例如，PM_Sensor_Data.PM2_5_CF成员存储的是接收到的PM2.5的浓度值(单位：ug/m^3)，PM_Sensor_Data.Count0_3nm成员存储的是0.3um以上颗粒物个数。

void PMSensor_DataReflash(void) // PM传感器数据回流函数 解析函数 ￥￥重要函数￥￥ { uint16_t Buffer_Len; //缓冲区长度 memset(&PM_Sensor_Data,0,(sizeof(PM_Sensor_Data) - 2)); / /PM_Sensor_Data.PM2_5_Old should not set to zero Buffer_Len = (uint16_t)((PM_Sensor_RxBuffer[2] << 8) | PM_Sensor_RxBuffer[3]); if(Buffer_Len == 28) //PMS1003/5003 { PM_Sensor_Data.Buffer_Len = 28; PM_Sensor_Data.PM1_0_CF = (uint16_t)((PM_Sensor_RxBuffer[4]<<8) | PM_Sensor_RxBuffer[5]); PM_Sensor_Data.PM2_5_CF = (uint16_t)((PM_Sensor_RxBuffer[6]<<8) | PM_Sensor_RxBuffer[7]); PM_Sensor_Data.PM10_CF = (uint16_t)((PM_Sensor_RxBuffer[8]<<8) | PM_Sensor_RxBuffer[9]); PM_Sensor_Data.PM1_0 = (uint16_t)((PM_Sensor_RxBuffer[10]<<8) | PM_Sensor_RxBuffer[11]); PM_Sensor_Data.PM2_5 = (uint16_t)((PM_Sensor_RxBuffer[12]<<8) | PM_Sensor_RxBuffer[13]); PM_Sensor_Data.PM10 = (uint16_t)((PM_Sensor_RxBuffer[14]<<8) | PM_Sensor_RxBuffer[15]); PM_Sensor_Data.Count0_3nm = (uint16_t)((PM_Sensor_RxBuffer[16]<<8) | PM_Sensor_RxBuffer[17]); PM_Sensor_Data.Count0_5nm = (uint16_t)((PM_Sensor_RxBuffer[18]<<8) | PM_Sensor_RxBuffer[19]); PM_Sensor_Data.Count1_0nm = (uint16_t)((PM_Sensor_RxBuffer[20]<<8) | PM_Sensor_RxBuffer[21]); PM_Sensor_Data.Count2_5nm = (uint16_t)((PM_Sensor_RxBuffer[22]<<8) | PM_Sensor_RxBuffer[23]); PM_Sensor_Data.Count5_0nm = (uint16_t)((PM_Sensor_RxBuffer[24]<<8) | PM_Sensor_RxBuffer[25]); PM_Sensor_Data.Count10nm = (uint16_t)((PM_Sensor_RxBuffer[26]<<8) | PM_Sensor_RxBuffer[27]); }

这是一个 PM 传感器数据回流函数，用于解析从传感器接收到的数据。函数中首先通过 memset 函数将 PM_Sensor_Data 变量清零，然后根据从 PM 传感器接收到的数据解析出各个参数的值，并存储到 PM_Sensor_Data 变量中。其中，PM_Sensor_RxBuffer 是一个缓冲区，存储着从 PM 传感器接收到的原始数据。函数将缓冲区中的数据解析出来，分别赋值给 PM_Sensor_Data 变量的各个成员。函数中还包含了一些对 PM_Sensor_Data 变量成员的赋值操作，具体含义需要结合上下文来理解。