关于U8glib库的问题

FutureMaker

请问U8glib库里面用到Wire库了吗？为什么大气压强的BMP085（Wire库）遇上OLED的U8glib库就不显示呢？

Super169

http://www.geek-workshop.com/thread-9931-1-1.html

FutureMaker

Super169 发表于 2014-5-28 09:32
http://www.geek-workshop.com/thread-9931-1-1.html

额，那个也是我问的

big8pie

我没碰到这问题，同时用过u8glib和18B20温度传感器，程序贴上看看？

FutureMaker

#include "U8glib.h"
#include "Wire.h"

#define BMP085_ADDRESS 0x77  // BMP085的I2C地址
const unsigned char OSS = 0;  // 采样设置
// 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bmp085GetTemperature(...)，它也同时用于bmp085GetPressure(...)
// 所以Temperature(...)必须在Pressure(...)之前声明
long b5;
//short temperature;
float pressure=0.0;


U8GLIB_SSD1306_128X64 u8g(2, 3, -1, 4,5);

void draw(void) {
  u8g.setFont(u8g_font_osb18);
  u8g.setPrintPos(0, 20);
  u8g.print("Pressure:");
  u8g.setPrintPos(2, 55);
  u8g.print(pressure/100.0);
  u8g.print("hPa");
}

void setup(void)
{
  Wire.begin();
  bmp085Calibration();
}

void loop(void) {
pressure = bmp085GetPressure(bmp085ReadUP());

delay(100);
   u8g.firstPage();  
  do {
    draw();
  } while( u8g.nextPage() );
}

void bmp085Calibration()
{
  ac1 = bmp085ReadInt(0xAA);
  ac2 = bmp085ReadInt(0xAC);
  ac3 = bmp085ReadInt(0xAE);
  ac4 = bmp085ReadInt(0xB0);
  ac5 = bmp085ReadInt(0xB2);
  ac6 = bmp085ReadInt(0xB4);
  b1 = bmp085ReadInt(0xB6);
  b2 = bmp085ReadInt(0xB8);
  mb = bmp085ReadInt(0xBA);
  mc = bmp085ReadInt(0xBC);
  md = bmp085ReadInt(0xBE);
}

// 计算压力
// 校准值必须是已知的
// B5在bmp085GetTemperature（...）需要使用，所以必须先调用。
// 返回值以Pa为单位
long bmp085GetPressure(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BMP085的'address'中读取一个字节
char bmp085Read(unsigned char address)
{
  unsigned char data;
  Wire.beginTransmission(BMP085_ADDRESS);
  Wire.write(address);
  Wire.endTransmission();
  Wire.requestFrom(BMP085_ADDRESS, 1);
  while(!Wire.available())  ;
  return Wire.read();
}

// 从BMP085读取两个字节
// 第一个字节是从'address'
// 第二个字节是从'address'+1
int bmp085ReadInt(unsigned char address)
{
  unsigned char msb, lsb;
  Wire.beginTransmission(BMP085_ADDRESS);
  Wire.write(address);
  Wire.endTransmission();
  Wire.requestFrom(BMP085_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 bmp085ReadUT()
{
  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(BMP085_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 = bmp085ReadInt(0xF6);
  return ut;
}

// 读取未补偿的压力值
unsigned long bmp085ReadUP()
{
  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(BMP085_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(BMP085_ADDRESS);
  Wire.write(0xF6);
  Wire.endTransmission();
  Wire.requestFrom(BMP085_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;
}

big8pie

我搞错了，我用的u8glib是spi接口，与你得不一样，且18b20是ti的onewire库，所以不具参考意义，抱歉

Super169

FutureMaker 发表于 2014-5-28 10:10
额，那个也是我问的

就是喇.
既然已問了, 在那裡答了, 你不去理會, 反而要再開一個新的?

FutureMaker

Super169 发表于 2014-5-28 22:07
就是喇.
既然已問了, 在那裡答了, 你不去理會, 反而要再開一個新的?

用的库不一样，不是一样的问题，怎么算是重复的？