(SKU:TOY0058)BMP180 大气压强传感器
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概述
如今在电子市场上,具有GPS功能的导航设备越来越多。借助全球卫星定位系统可以判定设备的经纬平面所处位置,但是无法得知目前的海拔高度。不过这一难题随着微型高精度气压传感器的出现而有望得以解决。 Bosch Sensortec开发出一款智能,超小体积,高精度数字传感器BMP180,适合智能的高精度测量和数据采集,输出高精度的压力(或高度)和温度测量数据。可与加速度计相互搭配,在没有GPS讯号的环境下,提供可靠的楼层侦测能力,以实现三维(3D)室内导航。
- 本传感器可以检测:温度,大气压强,海拔高度。
技术指标
工作电压:5V
工作范围:-40~+85 ℃
压强精度:0.12hPa/m
接口类型:4pin 排针和 1.27间距 IDC10座
引脚定义
如图,模块共有4个引脚,从上到下是5V,GND,SCL,SDA。模块可以通过I2C和单片机通信,5V供电。
特性曲线
简单例程
目标:测出当前环境下的大气压强和计算出芯片的海拔高度
1.先连接芯片与单片机(通过I2C接口),按照如下图的方式连接。
2.然后UNO通过usb与PC电脑连接。
3.拷贝以下的代码烧录进单片机。
标准代码
/**************************************************************************************/ /**********************DFRobot.com*****************************/ /***write by Tom Riddler Jun.16.14***/ /***if you got any progream,please contact me terminaterfxy@hotmail.com***/ #include <Wire.h> #define BMP180ADD 0xEE>>1 // I2C address of BMP180 //write is (0xEE) read is (0xEF) unsigned char OSS; /**********************MSB LSB******/ int ac1; // 0xAA 0xAB int ac2; // 0xAC 0xAD int ac3; // 0xAE 0xAE unsigned int ac4; // 0xB0 0xB1 unsigned int ac5; // 0xB2 0xB3 unsigned int ac6; // 0xB4 0xB5 int b1; // 0xB6 0xB7 int b2; // 0xB8 0xB9 int mb; // 0xBA 0xBB int mc; // 0xBC 0xBD int md; // 0xBE 0xBF float temperature; double pressure; double pressure2; long b5; double altitude; void setup() { Serial.begin(9600); Wire.begin(); OSS = 2; // Oversampling Setting 0: single 1: 2 times 2: 4 times 3: 8 times BMP180start(); } void loop() { calculate(); show(); delay(1000); } /** calculate centure **/ void calculate() { temperature = bmp180GetTemperature(bmp180ReadUT()); temperature = temperature*0.1; pressure = bmp180GetPressure(bmp180ReadUP()); pressure2 = pressure/101325; pressure2 = pow(pressure2,0.19029496); altitude = 44330*(1-pressure2); //altitude = 44330*(1-(pressure/101325)^0.19029496); } /** print reslut **/ void show() { Serial.print("Temperature: "); Serial.print(temperature, 1); //10 hexadecimal Serial.println(" C"); Serial.print("Pressure: "); Serial.print(pressure, 0); //10 hexadecimal Serial.println(" Pa"); Serial.print("altitude:"); Serial.print(altitude); Serial.println("m"); } /**BMP180 satrt program**/ void BMP180start() { /*MSB*/ ac1 = bmp180ReadDate(0xAA); //get full data ac2 = bmp180ReadDate(0xAC); ac3 = bmp180ReadDate(0xAE); ac4 = bmp180ReadDate(0xB0); ac5 = bmp180ReadDate(0xB2); ac6 = bmp180ReadDate(0xB4); b1 = bmp180ReadDate(0xB6); b2 = bmp180ReadDate(0xB8); mb = bmp180ReadDate(0xBA); mc = bmp180ReadDate(0xBC); md = bmp180ReadDate(0xBE); } /***BMP180 temperature Calculate***/ short bmp180GetTemperature(unsigned int ut) { long x1, x2; x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15; //x1=((ut-ac6)*ac5)/(2^15) x2 = ((long)mc << 11)/(x1 + md); //x2=(mc*2^11)/(x1+md) b5 = x1 + x2; //b5=x1+x2 return ((b5 + 8)>>4); //t=(b5+8)/(2^4) } /***BMP180 pressure Calculate***/ long bmp180GetPressure(unsigned long up) { long x1, x2, x3, b3, b6, p; unsigned long b4, b7; b6 = b5 - 4000; x1 = (b2 * (b6 * b6)>>12)>>11; x2 = (ac2 * b6)>>11; x3 = x1 + x2; b3 = (((((long)ac1)*4 + x3)<<OSS) + 2)>>2; x1 = (ac3 * b6)>>13; x2 = (b1 * ((b6 * b6)>>12))>>16; x3 = ((x1 + x2) + 2)>>2; b4 = (ac4 * (unsigned long)(x3 + 32768))>>15; b7 = ((unsigned long)(up - b3) * (50000>>OSS)); if (b7 < 0x80000000) p = (b7<<1)/b4; else p = (b7/b4)<<1; x1 = (p>>8) * (p>>8); x1 = (x1 * 3038)>>16; x2 = (-7357 * p)>>16; p += (x1 + x2 + 3791)>>4; return p; } /*** Read 1 bytes from the BMP180 ***/ int bmp180Read(unsigned char address) { unsigned char data; Wire.beginTransmission(BMP180ADD); Wire.write(address); Wire.endTransmission(); Wire.requestFrom(BMP180ADD, 1); while(!Wire.available()); return Wire.read(); } /*** Read 2 bytes from the BMP180 ***/ int bmp180ReadDate(unsigned char address) { unsigned char msb, lsb; Wire.beginTransmission(BMP180ADD); Wire.write(address); Wire.endTransmission(); Wire.requestFrom(BMP180ADD, 2); while(Wire.available()<2); msb = Wire.read(); lsb = Wire.read(); return (int) msb<<8 | lsb; } /*** read uncompensated temperature value ***/ unsigned int bmp180ReadUT() { unsigned int ut; Wire.beginTransmission(BMP180ADD); Wire.write(0xF4); // Write 0x2E into Register 0xF4 Wire.write(0x2E); // This requests a temperature reading Wire.endTransmission(); delay(5); // Wait at least 4.5ms ut = bmp180ReadDate(0xF6); // read MSB from 0xF6 read LSB from (16 bit) return ut; } /*** Read uncompensated pressure value from BMP180 ***/ unsigned long bmp180ReadUP() { unsigned char msb, lsb, xlsb; unsigned long up = 0; Wire.beginTransmission(BMP180ADD); Wire.write(0xF4); // Write 0x34+(OSS<<6) into register 0xF4 Wire.write(0x34 + (OSS<<6)); // 0x34+oss*64 Wire.endTransmission(); delay(2 + (3<<OSS)); // Wait for conversion, delay time dependent on OSS Wire.beginTransmission(BMP180ADD); Wire.write(0xF6); // Read register 0xF6 (MSB), 0xF7 (LSB), and 0xF8 (XLSB) Wire.endTransmission(); Wire.requestFrom(BMP180ADD, 3); while(Wire.available() < 3); // Wait for data to become available msb = Wire.read(); lsb = Wire.read(); xlsb = Wire.read(); up = (((unsigned long) msb << 16) | ((unsigned long) lsb << 8) | (unsigned long) xlsb) >> (8-OSS);//16 to 19 bit return up; }
4.打开串口调试助手可以看到参数。