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Hi!

I have an issue using LIS3MDL and Arduino library. I compiled and ran your "Serial" example, but instead of getting real-time values I receive the same value of X/Y/Z readings on every loop iteration. When I reset my Arduino, then I get a new value, but just once. I mean:

Serial output:

X1 Y1 Z1
X1 Y1 Z1
...
ARDUINO RESET
X2 Y2 Z2
X2 Y2 Z2
...

When I take "mag.enableDefault()" from setup() to loop() and I change "writeReg(CTRL_REG3, 0x00)" to "writeReg(CTRL_REG3, 0x01)" in "void LIS3MDL::enableDefault(void)" then I have a real-time reading, but hey - why should I configure device in the loop? Any ideas?

A Wire.endTransmission is only needed when writing data, it should not be used with Wire.requestFrom().

There is no need for a timeout after Wire.requestFrom(). When the Wire.requestFrom() returns, the complete I2C transmission has already finished, and the received data is waiting in the receive buffer inside the Wire library.

As far as I understand the LIS3MDL, it repeatedly measures the magnetic field and updates the magnetometer data registers. The DRDY bit goes high when all of x,y,z have been updated, and after that, the sensor pauses a finite time (according to the data rate) before taking a new measurement (in continuous mode.) An app reading the mag data should do so just after DRDY goes high, else the app could read the data while it was being changed by the device (i.e. it could be garbled?) So an app should poll the DRDY bit in the status register (using readReg()). Reading the X high byte clears DRDY bit. In other words, calls to read() should be synchronized to the DRDY bit going high. Is that a correct assessment?

please give an example of how to convert the values to a compass heading, i have tried

float Heading = 180*atan2( mag.m.y, mag.m.z)/PI;

but it just gives me a heading from 300 to 200 no matter how the compass is orientated