i2c_HMC5883.py: add i2c read & write example

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/python/i2c_HMC5883.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+# Author: Brendan Le Foll <brendan.le.foll@intel.com>
+# Copyright (c) 2014 Intel Corporation.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
+
+import mraa
+
+HMC5883L_CONF_REG_A = 0x00
+HMC5883L_CONF_REG_B =  0x01
+HMC5883L_CONT_MODE = 0x00
+HMC5883L_DATA_REG = 0x03
+GA_1_3_REG = 0x01
+
+x = mraa.I2c(0)
+x.address(0x1E)
+x.writeReg(HMC5883L_CONF_REG_B, GA_1_3_REG)
+x.writeReg(HMC5883L_CONF_REG_B, HMC5883L_CONT_MODE)
+
+x.address(0x1E)
+x.write(HMC5883L_DATA_REG)
+
+x.address(0x1E)
+m = "      "
+print (x.read(m))
+print (m)