The i2c scanner don’t find QMC5883LCompass and it don’t work on ESP32

[mateusmsantin]

Hi!
I used this code to find QMC5883L Compass, but don’t found.
The code compile on ESP32, but don’t show data.
What can I do to test it ?

`#include <Wire.h>

// Set I2C bus to use: Wire, Wire1, etc.
#define WIRE Wire

#define SDA 14 //3 // para teste 14
#define SCL 2 // para teste 2

void setup() {
Wire.begin(SDA, SCL);
//Wire.begin();

Serial.begin(9600);
while (!Serial)
delay(10);
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();
Serial.print (" # ");
Serial.print (address);
if (error == 0)
{
Serial.print("\n 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("Unknown 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
}`

[mprograms]

If you are not finding the chip's address then it is a hardware issue, not an issue with the library.

There are a few possibilities if you are not finding the chip.

• Your wiring might be wrong.
• The chip is bad.
• The chip is not QMC5883L.
• There is an issue with the I2C bus. In this case, try a different Arduino processor.

[mateusmsantin]

The library work with NodeMcu ?
When I connected the pins SCL - D1 / SDA - D2 and try calibrate, the program stop to work.

21:58:00.329 -> --------------- CUT HERE FOR EXCEPTION DECODER ---------------
21:58:00.363 -> H!���1�D���LH��l$hr�9�This will provide calibration settings for your QMC5883L chip. When prompted, move the magnetometer in all directions until the calibration is complete.
21:58:00.590 -> Calibration will begin in 5 seconds.
21:58:05.529 -> CALIBRATING. Keep moving your sensor...
21:58:08.456 ->
21:58:08.456 -> --------------- CUT HERE FOR EXCEPTION DECODER ---------------
21:58:08.519 ->
21:58:08.519 -> Soft WDT reset
21:58:08.519 ->
21:58:08.519 -> Exception (4):
21:58:08.583 -> epc1=0x40201618 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000
21:58:08.649 ->
21:58:08.649 -> >>>stack>>>
21:58:08.682 ->
21:58:08.682 -> ctx: cont
21:58:08.682 -> sp: 3ffffdf0 end: 3fffffd0 offset: 0160
21:58:08.714 -> 3fffff50: 3fffdad0 00001388 00000085 40203904
21:58:08.781 -> 3fffff60: 0000140d 00000000 00000000 00000000
21:58:08.846 -> 3fffff70: 00000000 00000000 3ffee8d0 3ffee950
21:58:08.880 -> 3fffff80: 3fffdad0 00000027 3ffee8d0 3ffee950
21:58:08.945 -> 3fffff90: 3fffdad0 3ffee688 3ffee8d0 4020109d
21:58:08.978 -> 3fffffa0: feefeffe feefeffe feefeffe 3ffee950
21:58:09.044 -> 3fffffb0: 3fffdad0 00000000 3ffee924 40202228
21:58:09.078 -> 3fffffc0: feefeffe feefeffe 3fffdab0 40100f91
21:58:09.144 -> <<<stack<<<

[blopa1961]

You might want to take a look at the Compass I published here:
https://www.rcgroups.com/forums/showthread.php?4535205-S-PORT-Compass-for-FrSky-telemetry

Working Arduino Nano code included, should be easily ported to nodeMCU.