calibrateCompass.py

#!/usr/bin/python
#   This program is used to calibrate the compass on a BerryIMUv1 or
#   BerryIMUv2.
#
#   Start this program and rotate your BerryIMU in all directions. 
#   You will see the maximum and minimum values change. 
#   After about 30secs or when the values are not changing, press Ctrl-C.
#   The program will printout some text which you then need to add to
#   berryIMU.py or berryIMU-simple.py


import sys,signal,os
import time
import math

import IMU
import datetime


def handle_ctrl_c(signal, frame):
    print " "
    print "magXmin = ",  magXmin
    print "magYmin = ",  magYmin
    print "magZmin = ",  magZmin
    print "magXmax = ",  magXmax
    print "magYmax = ",  magYmax
    print "magZmax = ",  magZmax
    sys.exit(130) # 130 is standard exit code for ctrl-c

IMU.initIMU()

#This will capture exit when using Ctrl-C
signal.signal(signal.SIGINT, handle_ctrl_c)


a = datetime.datetime.now()


#Preload the variables used to keep track of the minimum and maximum values
magXmin = 32767
magYmin = 32767
magZmin = 32767
magXmax = -32767
magYmax = -32767
magZmax = -32767


    
while True:

    #Read magnetometer values
    MAGx = IMU.readMAGx()
    MAGy = IMU.readMAGy()
    MAGz = IMU.readMAGz()
    
    
    
    if MAGx > magXmax:
        magXmax = MAGx
    if MAGy > magYmax:
        magYmax = MAGy
    if MAGz > magZmax:
        magZmax = MAGz

    if MAGx < magXmin:
        magXmin = MAGx
    if MAGy < magYmin:
        magYmin = MAGy
    if MAGz < magZmin:
        magZmin = MAGz

    print(" magXmin  %i  magYmin  %i  magZmin  %i  ## magXmax  %i  magYmax  %i  magZmax %i  " %(magXmin,magYmin,magZmin,magXmax,magYmax,magZmax))



    #slow program down a bit, makes the output more readable
    time.sleep(0.03)