BMP085是一款基于I2C接口的数字式气温、气压传感器,具有体积少易于使用的特点。 BMP085与MCU的连接关系为: SCLK——PB7 SDIN——PB8 其余的两个引脚则接3.3V工作电源
BMP085与开发板连接图
定义GPIO口输入及输出高低电平的语句为: #define SCL_Set() GPIO_SetPinLevel(GPIOB, GPIO_PIN7, GPIO_LEVEL_HIGH); // PB7 #define SCL_Clr() GPIO_SetPinLevel(GPIOB, GPIO_PIN7, GPIO_LEVEL_LOW);
#define SDA_Set() GPIO_SetPinLevel(GPIOB, GPIO_PIN8, GPIO_LEVEL_HIGH); // PB8 #define SDA_Clr() GPIO_SetPinLevel(GPIOB, GPIO_PIN8, GPIO_LEVEL_LOW);
#define IIC_SDA_IN GPIO_GetPinLevel(GPIOB, GPIO_PIN8)
#define IIC_INPUT_MODE_SET() GPIO_SetDir(GPIOB, GPIO_PIN8, GPIO_IN); #define IIC_OUTPUT_MODE_SET() GPIO_SetDir(GPIOB, GPIO_PIN8, GPIO_OUT);
配置相关引脚为输出功能的函数为: - void IIC_Init(void)
- {
- GPIO_SetDir(GPIOB, GPIO_PIN7, GPIO_OUT);
- GPIO_SetDir(GPIOB, GPIO_PIN8, GPIO_OUT);
- }
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辅助BMP085读写的基本函数有: - void IIC_Start(void)
- {
- IIC_OUTPUT_MODE_SET();
- SDA_Set();
- SCL_Set();
- udelay(5);
- SDA_Clr();
- udelay(5);
- SCL_Clr();
- }
- void IIC_Stop(void)
- {
- IIC_OUTPUT_MODE_SET();
- SDA_Clr();
- SCL_Clr();
- udelay(5);
- SCL_Set();
- udelay(5);
- SDA_Set();
- udelay(5);
- }
- void IIC_Ack(void)
- {
- SCL_Clr();
- IIC_OUTPUT_MODE_SET();
- SDA_Clr();
- udelay(2);
- SCL_Set();
- udelay(2);
- SCL_Clr();
- }
- void IIC_NAck(void)
- {
- SCL_Clr();
- IIC_OUTPUT_MODE_SET();
- SDA_Set();
- udelay(2);
- SCL_Set();
- udelay(2);
- SCL_Clr();
- }
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BMP085的初始化函数为: - void Init_BMP085()
- {
- ac1 = Multiple_read(0xAA);
- ac2 = Multiple_read(0xAC);
- ac3 = Multiple_read(0xAE);
- ac4 = Multiple_read(0xB0);
- ac5 = Multiple_read(0xB2);
- ac6 = Multiple_read(0xB4);
- b1 = Multiple_read(0xB6);
- b2 = Multiple_read(0xB8);
- mb = Multiple_read(0xBA);
- mc = Multiple_read(0xBC);
- md = Multiple_read(0xBE);
- }
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气温的读取函数为: - long bmp085ReadTemp(void)
- {
- IIC_Start();
- IIC_Send_Byte(BMP085_SlaveAddress);
- while(IIC_Wait_Ack()){}
- IIC_Send_Byte(0xF4);
- while(IIC_Wait_Ack()){}
- IIC_Send_Byte(0x2E);
- while(IIC_Wait_Ack()){}
- IIC_Stop();
- mdelay(10);
- return (long) Multiple_read(0xF6);
- }
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气压的读取函数为: - long bmp085ReadPressure(void)
- {
- long pressure = 0;
- IIC_Start();
- IIC_Send_Byte(BMP085_SlaveAddress);
- while(IIC_Wait_Ack()){}
- IIC_Send_Byte(0xF4);
- while(IIC_Wait_Ack()){}
- IIC_Send_Byte(0x34);
- while(IIC_Wait_Ack()){}
- IIC_Stop();
- mdelay(10);
- pressure = Multiple_read(0xF6);
- pressure &= 0x0000FFFF;
- return pressure;
- }
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实现图示输出效果的主程序为: - int main(void)
- {
- InitDelay();
- InitDebug();
- OLED_Init();
- OLED_Clear();
- OLED_ShowString(0,0,"AC8710 TEST",16);
- OLED_ShowString(0,2,"OLED Display",16);
- OLED_ShowString(0,4,"jinglixixi",16);
- OLED_ShowString(0,6,"2020.6.6",16);
- IIC_Init(); //BMP085
- Init_BMP085();
- while(1)
- {
- bmp085Convert();
- printf("temperature: %d C\r\n", temperature/10);
- printf("pressure: %d KPa\r\n", pressure/100);
- ConvAltitude();
- mdelay(1000);
- }
- }
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测量效果图
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