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ocrobot:sensor_suite:bmp180:main

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ocrobot:sensor_suite:bmp180:main [2019/06/14 08:10]
董凯萍 创建
ocrobot:sensor_suite:bmp180:main [2019/12/23 03:24] (当前版本)
董凯萍 [代码]
行 14: 行 14:
   - OCROBOT ALPHA LCD1602显示屏   - OCROBOT ALPHA LCD1602显示屏
   - OCROBOT ALPHA 双路锂电池扩展板   - OCROBOT ALPHA 双路锂电池扩展板
- +==== 代码 ==== 
 +<code cpp> 
 +/* 
 +  从BMP180传感器读取温度与气压数据。 
 +  通过Serial.print命令以9600波特率发送至串口监视器。 
 + */ 
 +#include <​LiquidCrystal_I2C.h>​  
 +#include <​Wire.h>​ 
 +#define BMP180_ADDRESS 0x77  // BMP180的I2C地址 
 +const unsigned char OSS = 0;  // 采样设置 
 +LiquidCrystal_I2C lcd(0x20, 16, 2); 
 +// 校准值 
 +int ac1; 
 +int ac2;  
 +int ac3;  
 +unsigned int ac4; 
 +unsigned int ac5; 
 +unsigned int ac6; 
 +int b1;  
 +int b2; 
 +int mb; 
 +int mc; 
 +int md; 
 +  
 +// b5用于计算bmp180GetTemperature(...),它也同时用于bmp180GetPressure(...) 
 +// 所以Temperature(...)必须在Pressure(...)之前声明 
 +  
 +long b5;  
 +short temperature;​ 
 +long pressure; 
 +  
 +void setup() 
 +{lcd.init(); ​                  //​初始化屏幕 
 +  lcd.backlight();​ 
 +  //​Serial.begin(9600);​ 
 +  Wire.begin();​ 
 +  bmp180Calibration();​ 
 +
 +  
 +void loop() 
 +
 +  temperature = bmp180GetTemperature(bmp180ReadUT());​ 
 +  pressure = bmp180GetPressure(bmp180ReadUP());​ 
 +  lcd.clear();​ 
 +  lcd.setCursor(0,​ 0); 
 +  lcd.print("​Temp:​ "); 
 +  lcd.setCursor(6,​ 0); 
 +  lcd.print(temperature,​ DEC); 
 +  lcd.println("​ C"); 
 +  lcd.setCursor(0,​ 1); 
 +  lcd.print("​Pressure:​ "); 
 +  lcd.setCursor(5,​ 1); 
 +  lcd.print(pressure,​ DEC); 
 +  lcd.println("​ Pa"​);​ 
 + 
 +  delay(1000);​ 
 +
 +  
 +// 存储所有的BMP180的校准值到全局变量 
 +// 校准值用来计算温度与气压 
 +// 这个函数应该放在程序的开头 
 +  
 +void bmp180Calibration() 
 +
 +  ac1 = bmp180ReadInt(0xAA);​ 
 +  ac2 = bmp180ReadInt(0xAC);​ 
 +  ac3 = bmp180ReadInt(0xAE);​ 
 +  ac4 = bmp180ReadInt(0xB0);​ 
 +  ac5 = bmp180ReadInt(0xB2);​ 
 +  ac6 = bmp180ReadInt(0xB4);​ 
 +  b1 = bmp180ReadInt(0xB6);​ 
 +  b2 = bmp180ReadInt(0xB8);​ 
 +  mb = bmp180ReadInt(0xBA);​ 
 +  mc = bmp180ReadInt(0xBC);​ 
 +  md = bmp180ReadInt(0xBE);​ 
 +
 +  
 +// 计算温度赋值给变量ut 
 +// 返回值的精度在0.1摄氏度 
 +  
 +short bmp180GetTemperature(unsigned int ut) 
 +
 +  long x1, x2; 
 +  x1 = (((long)ut - (long)ac6)*(long)ac5) >> 15; 
 +  x2 = ((long)mc << 11)/(x1 + md); 
 +  b5 = x1 + x2; 
 +  return ((b5 + 8)>>​4); ​  
 +
 +  
 +// 计算压力 
 +// 校准值必须是已知的 
 +// B5在bmp180GetTemperature(...)需要使用,所以必须先调用。 
 +// 返回值以Pa为单位 
 +  
 +long bmp180GetPressure(unsigned long up) 
 +  
 +
 +  long x1, x2, x3, b3, b6, p; 
 +  unsigned long b4, b7; 
 +  b6 = b5 - 4000; 
 +  // 计算B3 
 +  x1 = (b2 * (b6 * b6)>>​12)>>​11;​ 
 +  x2 = (ac2 * b6)>>​11;​ 
 +  x3 = x1 + x2; 
 +  b3 = (((((long)ac1)*4 + x3)<<​OSS) + 2)>>​2;​ 
 +  // 计算B4 
 +  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; 
 +
 +  
 +// 在BMP180的'​address'​中读取一个字节 
 +char bmp180Read(unsigned char address) 
 +
 +  unsigned char data; 
 +  Wire.beginTransmission(BMP180_ADDRESS);​ 
 +  Wire.write(address);​ 
 +  Wire.endTransmission();​ 
 +  Wire.requestFrom(BMP180_ADDRESS,​ 1); 
 +  while(!Wire.available()) ​ ; 
 +  return Wire.read();​ 
 +
 +// 从BMP180读取两个字节 
 +// 第一个字节是从'​address'​ 
 +// 第二个字节是从'​address'​+1 
 +int bmp180ReadInt(unsigned char address) 
 +
 +  unsigned char msb, lsb; 
 +  Wire.beginTransmission(BMP180_ADDRESS);​ 
 +  Wire.write(address);​ 
 +  Wire.endTransmission();​ 
 +  Wire.requestFrom(BMP180_ADDRESS,​ 2); 
 +  while(Wire.available()<​2);​ 
 +  msb = Wire.read();​ 
 +  lsb = Wire.read();​ 
 +  return (int) msb<<​8 | lsb; 
 +
 +  
 +// 读取未补偿的温度值 
 +unsigned int bmp180ReadUT() 
 +  
 +
 +  unsigned int ut; 
 +  // 在寄存器0xF4写入0x2E 
 +  // 这个用来请求进行温度读取 
 +  Wire.beginTransmission(BMP180_ADDRESS);​ 
 +  
 +  Wire.write(0xF4);​ 
 +  
 +  Wire.write(0x2E);​ 
 +  Wire.endTransmission();​ 
 +  // 至少等待4.5ms 
 +  delay(5); 
 +  // 从寄存器0xF6与0xF7读取两个字节 
 +  ut = bmp180ReadInt(0xF6);​ 
 +  return ut; 
 +
 +  
 +// 读取未补偿的压力值 
 +unsigned long bmp180ReadUP() 
 +
 +  unsigned char msb, lsb, xlsb; 
 +  unsigned long up = 0; 
 +  // 写入0x34+(OSS<<​6)到寄存器0xF4 
 +  // 请求气压数据读取 
 +  Wire.beginTransmission(BMP180_ADDRESS);​ 
 +  Wire.write(0xF4);​ 
 +  Wire.write(0x34 + (OSS<<​6));​ 
 +  Wire.endTransmission();​ 
 +  // 等待转换,延迟时间依赖于OSS 
 +  delay(2 + (3<<​OSS));​ 
 +  // 读取寄存器0xF6 (MSB), 0xF7 (LSB), and 0xF8 (XLSB) 
 +  Wire.beginTransmission(BMP180_ADDRESS);​ 
 +  Wire.write(0xF6);​ 
 +  Wire.endTransmission();​ 
 +  Wire.requestFrom(BMP180_ADDRESS,​ 3); 
 +  // 等待数据变为可用 
 +  while(Wire.available() < 3); 
 +  msb = Wire.read();​ 
 +  lsb = Wire.read();​ 
 +  xlsb = Wire.read();​ 
 +  up = (((unsigned long) msb << 16) | ((unsigned long) lsb << 8) | (unsigned long) xlsb) >> (8-OSS); 
 +  return up; 
 +
 +</​code>​
ocrobot/sensor_suite/bmp180/main.1560499847.txt.gz · 最后更改: 2019/06/14 08:10 由 董凯萍