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A I2C Scanner for Arduino
// --------------------------------------
// i2c_scanner
//
// Version 1
// This program (or code that looks like it)
// can be found in many places.
// For example on the Arduino.cc forum.
// The original author is not known.
// Version 2, Juni 2012, Using Arduino 1.0.1
// Adapted to be as simple as possible by Arduino.cc user Krodal
// Version 3, Feb 26 2013
// V3 by louarnold
// Version 4, March 3, 2013, Using Arduino 1.0.3
// by Arduino.cc user Krodal.
// Changes by louarnold removed.
// Scanning addresses changed from 0...127 to 1...119,
// according to the i2c scanner by Nick Gammon
// http://www.gammon.com.au/forum/?id=10896
// Version 5, March 28, 2013
// As version 4, but address scans now to 127.
// A sensor seems to use address 120.
//
//
// This sketch tests the standard 7-bit addresses
// Devices with higher bit address might not be seen properly.
//
#include <Wire.h>
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 found\n");
else
Serial.println("done\n");
delay(5000); // wait 5 seconds for next scan
}
@Opachiyo

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commented Jun 3, 2018

... good job.

@sbwaiker

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commented Aug 18, 2018

Hi
I am using this I2C scanner code on the ARDUINO TYPE IDE for GR Lychee board.
When i run the scanner , i get all the addresses as I2C Address on the serial monitor.!!
Instead there should be 4 addresses detected for gy80 sensor !!
Any Inputs on this ??

@Falsen

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commented Oct 25, 2018

Hi
I am using this I2C scanner code on the ARDUINO TYPE IDE for GR Lychee board.
When i run the scanner , i get all the addresses as I2C Address on the serial monitor.!!
Instead there should be 4 addresses detected for gy80 sensor !!
Any Inputs on this ??

When I run this on the MSP430 I get the same result. Every address is a match...?
Did you find a solution?

@noscene

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commented Oct 26, 2018

got also every address is a match -> until i add pullup resistors

@hdewitte

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commented Jun 28, 2019

Example hack to use the a soft i2c library. Replace:

#include <Wire.h>

by

#define SDA_PORT PORTD
#define SDA_PIN 4
#define SCL_PORT PORTD
#define SCL_PIN 5

// https://github.com/felias-fogg/SoftI2CMaster
#include <SoftWire.h>

SoftWire Wire;
@sidsbrs

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commented Aug 28, 2019

what is softwire in i2c?

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