初玩Arduino之I2C地址扫描

露其亚

淘宝了个I2C接口的128 64 OLED屏，结果怎么调试都不能显示。板子上印着I2C地址为0x78。直觉告诉我，地址有可能不对。

于是谷歌大法，搜索出一段搜索设备I2C地址的代码：

#include 

void setup()
{
  Wire.begin();

  Serial.begin(9600);
  Serial.println("nI2C Scanner");
}

void loop()
{
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ ) 
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4) 
    {
      Serial.print("Unknow error at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println("No I2C devices foundn");
  else
    Serial.println("donen");

  delay(5000);           // wait 5 seconds for next scan
}

终于搜索出正确的I2C地址了：原来是0x3C

总结：板子上印的地址是正确的，只不过Arduino和MSP430的寄存器是7位，需要右移一位

如下图16进制与二进制对比

0x78 1111000

0x3C 111100

david-chen

谢谢分享

zzzzzqwe12334

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