上海航芯ACM32G103开发板学习笔记09（大气压BMP180驱动）

qzc0927

上海航芯ACM32G103开发板学习笔记09（大气压BMP180驱动） [复制链接]

 

## ==11：IIC传感器BMP180驱动== ### 11.1：硬件接口 ​ BMP180是一款数字气压传感器，由德国公司Bosch Sensortec开发。它采用了微电机系统（MEMS）技术，可以测量大气压力和温度。该传感器采用低功耗设计，可通过I2C总线与微控制器或单片机通信。BMP180具有高精度和快速响应的特点，适用于气压计、天气预报、高度测量、室内导航等应用领域。它的工作温度范围广泛，从-40摄氏度到+85摄氏度。此外，BMP180还提供了温度补偿功能，可以减少温度对气压测量的影响。 ​ 硬件接口分布： ​ ### 11.2：软件设计 采用模拟IIC的方式来进行实现。具体实现思路如下： 1：配置GPIO引脚状态。 ```C //初始化IIC void IIC_Init(void) { GPIO_InitTypeDefGPIO_InitStruct; /* EnableClock */ BSP_BMP180_CLK_ENABLE(); GPIO_InitStruct.Pin = BSP_BMP180_SCL_PIN|BSP_BMP180_SDA_PIN; GPIO_InitStruct.Mode = BSP_BMP180_MODE; GPIO_InitStruct.Pull = BSP_BMP180_PULL; GPIO_InitStruct.Drive = BSP_BMP180_DRIVE; GPIO_InitStruct.Alternate = BSP_BMP180_ALTERNATE; GPIO_Init(BSP_BMP180_GPIO, &GPIO_InitStruct); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_SET); } ``` 2：配置模拟IIC的时序 ```C void SDA_OUT(void) { GPIO_InitTypeDefGPIO_InitStruct; /* EnableClock */ BSP_BMP180_CLK_ENABLE(); GPIO_InitStruct.Pin = BSP_BMP180_SDA_PIN; GPIO_InitStruct.Mode = BSP_BMP180_MODE; GPIO_InitStruct.Pull = BSP_BMP180_PULL; GPIO_InitStruct.Drive = BSP_BMP180_DRIVE; GPIO_InitStruct.Alternate = BSP_BMP180_ALTERNATE; GPIO_Init(BSP_BMP180_GPIO, &GPIO_InitStruct); } void SDA_IN(void) { GPIO_InitTypeDefGPIO_InitStruct; /* EnableClock */ BSP_BMP180_CLK_ENABLE(); GPIO_InitStruct.Pin = BSP_BMP180_SDA_PIN; GPIO_InitStruct.Mode = GPIO_MODE_INPUT; GPIO_InitStruct.Pull = BSP_BMP180_PULL; GPIO_InitStruct.Drive = BSP_BMP180_DRIVE; GPIO_InitStruct.Alternate = BSP_BMP180_ALTERNATE; GPIO_Init(BSP_BMP180_GPIO, &GPIO_InitStruct); } //产生IIC起始信号 void IIC_Start(void) { SDA_OUT(); //sda线输出 GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_SET); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); delay_us(4); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_RESET);//START:when CLK is high,DATA change form high to low delay_us(4); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET);//钳住I2C总线，准备发送或接收数据 } //产生IIC停止信号 void IIC_Stop(void) { SDA_OUT();//sda线输出 GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_RESET);//STOP:when CLK is high DATA change form low to high delay_us(4); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_SET); //发送I2C总线结束信号 delay_us(4); } //等待应答信号到来 //返回值：1，接收应答失败 // 0，接收应答成功 uint8_t IIC_Wait_Ack(void) { uint8_t ucErrTime=0; SDA_IN(); //SDA设置为输入 GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_SET); delay_us(1); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); delay_us(1); while(GPIO_ReadPin(BSP_BMP180_GPIO,BSP_BMP180_SDA_PIN)) //IO口数据读入 { ucErrTime++; if(ucErrTime>250) { IIC_Stop(); return 1; } } GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET);//时钟输出0 return 0; } //产生ACK应答 void IIC_Ack(void) { GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); SDA_OUT(); //释放一个数据线时，ACK应答信号为0时 GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_RESET); //发送成功 delay_us(2); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); delay_us(2); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); } //不产生ACK应答 void IIC_NAck(void) { GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); SDA_OUT(); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_SET); delay_us(2); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); delay_us(2); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); } //IIC发送一个字节 //返回从机有无应答 //1，有应答 //0，无应答 void IIC_Send_Byte(uint8_t txd) { uint8_t t; SDA_OUT(); //数据输出 GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); for(t=0;t<8;t++) { if((txd&0x80)>>7) { GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_SET); } else { GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SDA_PIN, GPIO_PIN_RESET); } txd<<=1; delay_us(2); //对TEA5767这三个延时都是必须的 GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); delay_us(2); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); delay_us(2); } } //读1个字节，ack=1时，发送ACK，ack=0，发送nACK uint8_t IIC_Read_Byte(unsigned char ack) { uint8_t i,receive=0; SDA_IN(); //SDA设置为输入 for(i=0;i<8;i++ ) { GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_RESET); delay_us(2); GPIO_WriteBit(BSP_BMP180_GPIO, BSP_BMP180_SCL_PIN, GPIO_PIN_SET); receive<<=1; if(GPIO_ReadPin(BSP_BMP180_GPIO,BSP_BMP180_SDA_PIN))receive++; //如果数据输出了，读取一个字节 delay_us(1); } if (!ack) IIC_NAck();//发送nACK else IIC_Ack(); //发送ACK return receive; } ``` 3：bmp180驱动 ```C //BMP180初始化 //对使用的IIC端口进行初始化 void drv_bmp_init(void) { IIC_Init(); } //写一个数据到BMP180 void BMP_WriteOneByte(uint8_t WriteAddr,uint8_t DataToWrite) { IIC_Start(); IIC_Send_Byte(0xEE);//发送一个字节（地址为 Module address 0cEE） IIC_Wait_Ack();//等待 IIC_Send_Byte(WriteAddr);//发送字节的地址 IIC_Wait_Ack(); IIC_Send_Byte(DataToWrite);//发送字节地址中的数据 IIC_Wait_Ack(); IIC_Stop(); } //从BMP180读一个字节数据 uint8_t BMP_ReadOneByte(uint8_t ReadAddr) { uint8_t data = 0; IIC_Start(); IIC_Send_Byte(0xEE); IIC_Wait_Ack(); IIC_Send_Byte(ReadAddr); IIC_Wait_Ack(); IIC_Start(); IIC_Send_Byte(0xEF); //把读取的字节存到下一个地址（0xef)中去 IIC_Wait_Ack(); data = IIC_Read_Byte(1); //读取地址总的字节 IIC_Stop(); return data; } //从BMP180读一个16位的数据 short BMP_ReadTwoByte(uint8_t ReadAddr) { short data; uint8_t msb,lsb; IIC_Start(); IIC_Send_Byte(0xEE);//发送字节（地址为 Module address 0cEE） IIC_Wait_Ack(); IIC_Send_Byte(ReadAddr); IIC_Wait_Ack(); IIC_Start(); IIC_Send_Byte(0xEF);//把读取的字节存到下一个地址（0xef)中去 IIC_Wait_Ack(); msb = IIC_Read_Byte(1);//读取16位的高八位 lsb = IIC_Read_Byte(0);//读取16位的低八位 IIC_Stop(); data = msb*256 + lsb;//以16位的二进制数据给data return data; } //从BMP180的获取计算参数 void BMP_ReadCalibrationData(void) { bmp180.AC1 = BMP_ReadTwoByte(0xAA); bmp180.AC2 = BMP_ReadTwoByte(0xAC); bmp180.AC3 = BMP_ReadTwoByte(0xAE); bmp180.AC4 = BMP_ReadTwoByte(0xB0); bmp180.AC5 = BMP_ReadTwoByte(0xB2); bmp180.AC6 = BMP_ReadTwoByte(0xB4); bmp180.B1= BMP_ReadTwoByte(0xB6); bmp180.B2= BMP_ReadTwoByte(0xB8); bmp180.MB= BMP_ReadTwoByte(0xBA); bmp180.MC= BMP_ReadTwoByte(0xBC); bmp180.MD= BMP_ReadTwoByte(0xBE); } //从BMP180读取未修正的温度 long BMP_Read_UT(void) { long temp = 0; BMP_WriteOneByte(0xF4,0x2E); DelayMs(5); temp = (long)BMP_ReadTwoByte(0xF6); return temp; } //从BMP180读取未修正的大气压 long BMP_Read_UP(void) { long pressure = 0; BMP_WriteOneByte(0xF4,0x34); DelayMs(5); pressure = (long)BMP_ReadTwoByte(0xF6); //pressure = pressure + BMP_ReadOneByte(0xf8); pressure &= 0x0000FFFF; //位运算，将pressure中的高八位清0，低八位保留 return pressure; } //用获取的参数对温度和大气压进行修正，并计算海拔 void BMP_UncompemstatedToTrue(void) { bmp180.UT = BMP_Read_UT();//第一次读取错误测试的实际的温度值只有-78度 海拔高度有2500多米（改变延时没用） bmp180.UT = BMP_Read_UT();//进行第二次读取修正参数读取两次温度值正确 bmp180.UP = BMP_Read_UP();//第一次读取压强值 /**--得到温度值--**/ bmp180.X1 = ((bmp180.UT - bmp180.AC6) * bmp180.AC5) >> 15; bmp180.X2 = (((long)bmp180.MC) << 11) / (bmp180.X1 + bmp180.MD); bmp180.B5 = bmp180.X1 + bmp180.X2; bmp180.Temp= (bmp180.B5 + 8) >> 4; /**--得到气压值--**/ bmp180.B6 = bmp180.B5 - 4000; bmp180.X1 = ((long)bmp180.B2 * (bmp180.B6 * bmp180.B6 >> 12)) >> 11; bmp180.X2 = ((long)bmp180.AC2) * bmp180.B6 >> 11; bmp180.X3 = bmp180.X1 + bmp180.X2; bmp180.B3 = ((((long)bmp180.AC1) * 4 + bmp180.X3) + 2) /4; bmp180.X1 = ((long)bmp180.AC3) * bmp180.B6 >> 13; bmp180.X2 = (((long)bmp180.B1) *(bmp180.B6*bmp180.B6 >> 12)) >>16; bmp180.X3 = ((bmp180.X1 + bmp180.X2) + 2) >> 2; bmp180.B4 = ((long)bmp180.AC4) * (unsigned long)(bmp180.X3 + 32768) >> 15; bmp180.B7 = ((unsigned long)bmp180.UP - bmp180.B3) * 50000; if(bmp180.B7 < 0x80000000) { bmp180.p = (bmp180.B7 * 2) / bmp180.B4; } else { bmp180.p = (bmp180.B7 / bmp180.B4) * 2; } bmp180.X1 = (bmp180.p >> 8) * (bmp180.p >>8); bmp180.X1 = (((long)bmp180.X1) * 3038) >> 16; bmp180.X2 = (-7357 * bmp180.p) >> 16; bmp180.p = bmp180.p + ((bmp180.X1 + bmp180.X2 + 3791) >> 4); /**--得到海拔高度--**/ bmp180.altitude = 44330 * (1-pow(((bmp180.p) / 101325.0),(1.0/5.255))); } ``` ### 11.3：测试结果输出  实物接线图：