bmp280大气压传感器
前言
本文着重介绍bmp280(GY-BM E/P 280模块)的原理、功能、使用方法、不同公司的型号以及提供适用于不同单片机的代码
一、bmp280大气压传感器外观
二、原理图
三、相关参数讲解
1.引脚
六个引脚，名称与功能如下;
pin1：VCC（3.3V供电,切记不可以接5v）
pin2：GND
pin3：SCL（I2C通信模式时钟信号）
pin4：SDA（I2C通信模式数据信号）
pin5：CSB（SPI通信模式下用到的引脚，片选引脚，拉低后启用）
pin6：SDO（传感器地址控制位）
2.温度和压强数据测量范围
温度范围为： -40 ～ 85 度
压强范围为：300 ～ 1100 hPa
3.通讯方式（i2c和spi）
i2c通讯方式：SCL --> 时钟线、SDI --> 数据线、SDO --> 片地址的LSB(最低加权位)、CSB --> Vdd 拉高
spi通讯方式：SCL --> 时钟线、SDI --> 数据输入线（三线模式下为双向数据线）、SDO --> 数据输出线（3线模式下无用）、CSB --> 片选引脚，拉低后启用
4.使用模式
使用模式分为三种睡眠模式、触发模式和正常模式
睡眠模式：可以理解为不工作了
触发模式：测一次之后传感器进入睡眠状态（目的也是为了节省资源）
四、内部寄存器总览
五、常用单片机代码示例
arduino开发代码
对于arduino开发较为简单
#include <Wire.h>
#define BME280_ADDRESS 0x76
unsigned long int hum_raw,temp_raw,pres_raw;
signed long int t_fine;
uint16_t dig_T1;
int16_t dig_T2;
int16_t dig_T3;
uint16_t dig_P1;
int16_t dig_P2;
int16_t dig_P3;
int16_t dig_P4;
int16_t dig_P5;
int16_t dig_P6;
int16_t dig_P7;
int16_t dig_P8;
int16_t dig_P9;
int8_t dig_H1;
int16_t dig_H2;
int8_t dig_H3;
int16_t dig_H4;
int16_t dig_H5;
int8_t dig_H6;
void setup()
{
uint8_t osrs_t = 1; //Temperature oversampling x 1
uint8_t osrs_p = 1; //Pressure oversampling x 1
uint8_t osrs_h = 1; //Humidity oversampling x 1
uint8_t mode = 3; //Normal mode
uint8_t t_sb = 5; //Tstandby 1000ms
uint8_t filter = 0; //Filter off
uint8_t spi3w_en = 0; //3-wire SPI Disable
uint8_t ctrl_meas_reg = (osrs_t << 5) | (osrs_p << 2) | mode;
uint8_t config_reg = (t_sb << 5) | (filter << 2) | spi3w_en;
uint8_t ctrl_hum_reg = osrs_h;
Serial.begin(9600);
Wire.begin();
writeReg(0xF2,ctrl_hum_reg);
writeReg(0xF4,ctrl_meas_reg);
writeReg(0xF5,config_reg);
readTrim(); //
}
void loop()
{
double temp_act = 0.0, press_act = 0.0,hum_act=0.0;
signed long int temp_cal;
unsigned long int press_cal,hum_cal;
readData();
temp_cal = calibration_T(temp_raw);
press_cal = calibration_P(pres_raw);
hum_cal = calibration_H(hum_raw);
temp_act = (double)temp_cal / 100.0;
press_act = (double)press_cal / 100.0;
hum_act = (double)hum_cal / 1024.0;
Serial.print("TEMP : ");
Serial.print(temp_act);
Serial.print(" DegC PRESS : ");
Serial.print(press_act);
Serial.print(" hPa HUM : ");
Serial.print(hum_act);
Serial.println(" %");
delay(1000);
}
void readTrim()
{
uint8_t data[32],i=0;
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0x88);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,24);
while(Wire.available()){
data[i] = Wire.read();
i++;
}
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xA1);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,1);
data[i] = Wire.read();
i++;
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xE1);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,7);
while(Wire.available()){
data[i] = Wire.read();
i++;
}
dig_T1 = (data[1] << 8) | data[0];
dig_T2 = (data[3] << 8) | data[2];
dig_T3 = (data[5] << 8) | data[4];
dig_P1 = (data[7] << 8) | data[6];
dig_P2 = (data[9] << 8) | data[8];
dig_P3 = (data[11]<< 8) | data[10];
dig_P4 = (data[13]<< 8) | data[12];
dig_P5 = (data[15]<< 8) | data[14];
dig_P6 = (data[17]<< 8) | data[16];
dig_P7 = (data[19]<< 8) | data[18];
dig_P8 = (data[21]<< 8) | data[20];
dig_P9 = (data[23]<< 8) | data[22];
dig_H1 = data[24];
dig_H2 = (data[26]<< 8) | data[25];
dig_H3 = data[27];
dig_H4 = (data[28]<< 4) | (0x0F & data[29]);
dig_H5 = (data[30] << 4) | ((data[29] >> 4) & 0x0F);
dig_H6 = data[31];
}
void writeReg(uint8_t reg_address, uint8_t data)
{
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(reg_address);
Wire.write(data);
Wire.endTransmission();
}
void readData()
{
int i = 0;
uint32_t data[8];
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xF7);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,8);
while(Wire.available()){
data[i] = Wire.read();
i++;
}
pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
hum_raw = (data[6] << 8) | data[7];
}
signed long int calibration_T(signed long int adc_T)
{
signed long int var1, var2, T;
var1 = ((((adc_T >> 3) - ((signed long int)dig_T1<<1))) * ((signed long int)dig_T2)) >> 11;
var2 = (((((adc_T >> 4) - ((signed long int)dig_T1)) * ((adc_T>>4) - ((signed long int)dig_T1))) >> 12) * ((signed long int)dig_T3)) >> 14;
t_fine = var1 + var2;
T = (t_fine * 5 + 128) >> 8;
return T;
}
unsigned long int calibration_P(signed long int adc_P)
{
signed long int var1, var2;
unsigned long int P;
var1 = (((signed long int)t_fine)>>1) - (signed long int)64000;
var2 = (((var1>>2) * (var1>>2)) >> 11) * ((signed long int)dig_P6);
var2 = var2 + ((var1*((signed long int)dig_P5))<<1);
var2 = (var2>>2)+(((signed long int)dig_P4)<<16);
var1 = (((dig_P3 * (((var1>>2)*(var1>>2)) >> 13)) >>3) + ((((signed long int)dig_P2) * var1)>>1))>>18;
var1 = ((((32768+var1))*((signed long int)dig_P1))>>15);
if (var1 == 0)
{
return 0;
}
P = (((unsigned long int)(((signed long int)1048576)-adc_P)-(var2>>12)))*3125;
if(P<0x80000000)
{
P = (P << 1) / ((unsigned long int) var1);
}
else
{
P = (P / (unsigned long int)var1) * 2;
}
var1 = (((signed long int)dig_P9) * ((signed long int)(((P>>3) * (P>>3))>>13)))>>12;
var2 = (((signed long int)(P>>2)) * ((signed long int)dig_P8))>>13;
P = (unsigned long int)((signed long int)P + ((var1 + var2 + dig_P7) >> 4));
return P;
}
unsigned long int calibration_H(signed long int adc_H)
{
signed long int v_x1;
v_x1 = (t_fine - ((signed long int)76800));
v_x1 = (((((adc_H << 14) -(((signed long int)dig_H4) << 20) - (((signed long int)dig_H5) * v_x1)) +
((signed long int)16384)) >> 15) * (((((((v_x1 * ((signed long int)dig_H6)) >> 10) *
(((v_x1 * ((signed long int)dig_H3)) >> 11) + ((signed long int) 32768))) >> 10) + (( signed long int)2097152)) *
((signed long int) dig_H2) + 8192) >> 14));
v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * ((signed long int)dig_H1)) >> 4));
v_x1 = (v_x1 < 0 ? 0 : v_x1);
v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
return (unsigned long int)(v_x1 >> 12);
}
stm32部分代码
stm32这个部分有些人会觉得它会比较难一点，其实每个对应的传感器都有人家写好的的代码，直接调用输出就好，但是为了自己的学习还是要多熟悉原理
对于这个部分个人觉得下面这个博主写的很好link
总结
对于bmp280的讲解在网络上的讲解也比较少，本篇文章以实用和易懂为主，如果详细了解还是要看他的中文手册，我也看到其它博主的讲解感觉也都挺好的，附上他们的链接可做参考学习其他博主文章链接一
后续还会更新自己其它了解或者使用过的传感器的相关知识。