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https://github.com/robert-hh/QMC5883

Python class for the QMC5883 Three-Axis Digital Compass IC
https://github.com/robert-hh/QMC5883

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Python class for the QMC5883 Three-Axis Digital Compass IC

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# QMC5883L/QMC5883P: Python class for the QMC5883L/QMC5883P Three-Axis Digital Compass IC



This is a very short and simple class. It uses the I2C bus for the interface.



Initial code by Sebastian Folz, M.Sc. at

http://nobytes.blogspot.com/2018/03/qmc5883-magnetic-field-sensor.html



## Types of QMC5883



There are two types of QMC5883 available on the market. 



* QMC5883L - Have less range modes, maximum magnetic field range is 8G (800 uT). And maximum output rate is 200hz. Datasheet available @LCSC (https://datasheet.lcsc.com/szlcsc/QST-QMC5883L-TR_C192585.pdf)

* QMC5883P - Sensivity range is 30G. Accuracy overall is worser than in QMC5883L. Maximum output rate is 1.5khz. No temperature sensor. Datasheet available @LCSC (https://datasheet.lcsc.com/lcsc/2108072330_QST-QMC5883P_C2847467.pdf) 



The chips have totally different PCB package. On the market available both variant, but if takes Arduino modules, mostly it will be QMC5883L (@see GY-273 modules)

Register map of these chips are totally different. 



## Constructor



The both drivers uses the same interface (ie parent class) - `mag_base`. Could be selected, any of available driver `QMC5883L` or `QMC5883P`.

Next examples use QMC5883P, but due to the same interface class could be replaced with QMC5883L



### QMC5883 = QMC5883P(i2c [, temp_offset])



- i2c is an I2C object which has to be created by the caller.

- temp_offset specifies the offset to the temperature, as returned by the method (only in QMC5883L)

read_scaled. The unit is °C, the default is 50 °C.



## Methods



### (x, y, z, t) = QMC5883.read_raw()

Return the raw reading for the x,y, and z axis as well as the raw temperature

reading. The values are not scaled according to the sensitivity or possible offsets.



### (x, y, z, t) = QMC5883.read_scaled()

Return the scaled reading for the x,y, and z axis as well as the temperature

reading. The x ,y and z readings are scaled to Gauss, the temperature to °C with compensated offset

On QMC5883P temperature value is always zero. 



### QMC5883.set_sampling rate(sampling_rate)

Sets the sampling rate of the sensor. Accepted values are:



| Value | Sampling rate |

| :---: | :-----------: |

|   0   |     10 Hz     |

|   1   |     50 Hz     |

|   2   |    100 Hz     |

|   3   |    200 Hz     |



### QMC5883.set_oversampling(oversampling)

Sets the oversampling factor of the sensor. Accepted values are:



| Value | Oversampling |

| :---: | :----------: |

|   0   |     512      |

|   1   |     256      |

|   2   |     128      |

|   3   |      64      |



### QMC5883.set_range(range)

Sets the magnetic field range of the sensor. Accepted values are:



| Value |  Range   | 

| :---: | :------: |

|   0   | 2 Gauss  |

|   1   | 8 Gauss  |

|   1   | 12 Gauss (QMC5883P only) |

|   1   | 30 Gauss (QMC5883P only) |



### QMC5883.reset()



Resets the device using the previously configured settings. This call is **not**

required when settings are changed.



```

# Example for Pycom device.

# Connections:

# xxPy | QMC5883

# -----|-------

# P9   |  SDA

# P10  |  SCL

#

from machine import I2C

from QMC5883 import QMC5883P



i2c = I2C(0, I2C.MASTER)

qmc5883 = QMC5883P(i2c)



x, y, z, _ = qmc5883.read_scaled()

```