1  """ Calibrate the magnetometer and print out the hard-iron calibrations """
 2  
 3  import time
 4  import board
 5  import busio
 6  import adafruit_lis2mdl
 7  
 8  i2c = busio.I2C(board.SCL, board.SDA)
 9  magnetometer = adafruit_lis2mdl.LIS2MDL(i2c)
10  
11  # calibration for magnetometer X (min, max), Y and Z
12  hardiron_calibration = [[1000, -1000], [1000, -1000], [1000, -1000]]
13  
14  
15  def calibrate():
16      start_time = time.monotonic()
17  
18      # Update the high and low extremes
19      while time.monotonic() - start_time < 10.0:
20          magval = magnetometer.magnetic
21          print("Calibrating - X:{0:10.2f}, Y:{1:10.2f}, Z:{2:10.2f} uT".format(*magval))
22          for i, axis in enumerate(magval):
23              hardiron_calibration[i][0] = min(hardiron_calibration[i][0], axis)
24              hardiron_calibration[i][1] = max(hardiron_calibration[i][1], axis)
25      print("Calibration complete:")
26      print("hardiron_calibration =", hardiron_calibration)
27  
28  
29  print("Prepare to calibrate! Twist the magnetometer around in 3D in...")
30  print("3...")
31  time.sleep(1)
32  print("2...")
33  time.sleep(1)
34  print("1...")
35  time.sleep(1)
36  
37  calibrate()