Arduino I2C 扫描器

当我们在做一些用到 I2C 总线连接的设计，经常苦恼无法确定 I2C 是否连接正确，主从设备是否可以正常通信，这时候我们可以通过下面这个例程，来测试主机是否能找到从设备，需要用到 Arduino Wire 库。

#include<Wire.h>
void setup()
{
	Wire.begin();
	Serial.begin(9600);
	Serial.println("====== I2C Scanner Getting Started");
}
void loop()
{
byte error, address;
int nDevices;
Serial.println("Scanning...");
nDevices = 0;
for(address = 1; address < 127; 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 found\n");
else
Serial.println("done\n");
delay(5000);// wait 5 seconds for next scan
}
}