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Description
Hi,
I am trying to use the i2C scanner with this dev board, but the scanner always returns, "No I2C devices found." But when I decided to try using the STM board, it worked.
Any idea what could be wrong?
// --------------------------------------
// 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 know.
// 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.
//
/* Example pinmap for Bluepill I2Cs (by Testato)
I2C-1 standard pins: PB7(sda) PB6(scl)
Use it by "Wire" without pin declaration
Wire.begin();
I2C-1 alternative pins: PB9(sda) PB8(scl)
Remap the first I2C before call begin()
Wire.setSDA(PB9);
Wire.setSCL(PB8);
Wire.begin();
I2C-2: PB11(sda) PB10(scl)
Remap the second I2C before call begin()
Wire.setSDA(PB11);
Wire.setSCL(PB10);
Wire.begin();
If you want to use the two I2Cs simultaneously, create a new instance for the second I2C
TwoWire Wire2(PB11,PB10);
Wire2.begin();
*/
#include <Wire.h>
TwoWire Wire2(PB11,PB10,1);
void setup()
{
delay(10000);
Serial.begin(9600);
Wire2.begin();
Wire.begin();
Serial.println("\nI2C Scanner");
}
void loop()
{
byte error, error2, 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.println(address, HEX);
nDevices++;
}
else if (error == 4) {
Serial.print("Unknown error at address 0x");
if (address < 16)
Serial.print("0");
Serial.println(address, HEX);
}
Wire2.beginTransmission(address);
error2 = Wire2.endTransmission();
if(error2 == 0) {
Serial.print("I2C B device found at address 0x");
if (address < 16)
Serial.print("0");
Serial.println(address, HEX);
nDevices++;
}
else if (error2 == 4) {
Serial.print("Unknown error at address 0x");
if (address < 16)
Serial.print("0");
Serial.println(address, HEX);
}
}
if (nDevices == 0)
Serial.println("No I2C devices found");
else
Serial.println("done");
delay(5000); // wait 5 seconds for next scan
}