====== compas2OSC.py ======

=====  CMPS10 - Tilt Compensated Compass Module =====
  * [[http://www.robotshop.com/en/devantech-tilt-magnetic-compass.html]]
  * http://www.hobbytronics.co.uk/cmps10-tilt-compass

** Registre de 23 bytes :**
  * 0 	Software version
  * 1  	Compass Bearing as a byte, i.e. 0-255 for a full circle
  * 2,3 Compass Bearing as a word, i.e. 0-3599 for a full circle, representing 0-359.9 degrees.
  * 4  	Pitch angle - signed byte giving angle in degrees from the horizontal plane
  * 5  	Roll angle - signed byte giving angle in degrees from the horizontal plane
  * 6,,7,8,9 	Unused
  * 10,11 Magnetometer X axis raw output, 16 bit signed integer with register 10 being the upper 8 bits
  * 12,13 Magnetometer Y axis raw output, 16 bit signed integer with register 12 being the upper 8 bits
  * 14,15 Magnetometer Z axis raw output, 16 bit signed integer with register 14 being the upper 8 bits
  * 16,17 Accelerometer  X axis raw output, 16 bit signed integer with register 16 being the upper 8 bits
  * 18,19 Accelerometer  Y axis raw output, 16 bit signed integer with register 18 being the upper 8 bits
  * 20,21 Accelerometer  Z axis raw output, 16 bit signed integer with register 20 being the upper 8 bits
  * 22    Command register




===== HMC6352 =====


la boussole HMC6352 est sur un bus i2c.
Donne l'angle au nord en degré dans le sens horaire (heading)
Mais pas de compensation en fonction de l'inclinaison de la tête !
d'ou pas d'usage ..

<code>
#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys,time,liblo
from smbus import SMBus

BUS_NUMBER = 2
IP='127.0.0.1'
PORT=9001
ADRS=33 # 0x21 - compass
osc_path='/pos/compas'

b = SMBus(BUS_NUMBER) # 0 indicates /dev/i2c-0
data = {}

try:
        target = liblo.Address('127.0.0.1',9001)
except liblo.AddressError, err:
        print str(err)
        sys.exit()

while True:
        try:
                b.write_byte(0x21,0x41) # send 'A' to HMC6352 compass
                time.sleep(0.02)
                data_block = b.read_i2c_block_data(0x21,2)
                heading = (data_block[0] * 2**8 + data_block[1]) / 10
                time.sleep(0.02)
#               print('Compas',heading)
                liblo.send(target, osc_path, heading)
        except KeyError:
                pass
        except KeyboardInterrupt:
                quit()
        except StopIteration:
                session = None
                print "end"
        except:
#               print('echec')
                continue

</code>