i2c.hpp: add I2c::writeReg method

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

api/maa/i2c.hpp

@@ -108,6 +108,19 @@ class I2c {
         maa_result_t write(const unsigned char* data, int length) {
             return maa_i2c_write(m_i2c, data, length);
         }
+
+        /**
+         * Write to an i2c register
+         *
+         * @param reg Register to write to
+         * @param data Value to write to register
+         * @return Result of operation
+         */
+        maa_result_t writeReg(const unsigned char reg, const unsigned char data) {
+            const unsigned char buf[2] = {reg, data};
+            return maa_i2c_write(m_i2c, buf, 2);
+        }
+
         /**
          * Write multiple bytes to the bus
          *

examples/python/rgblcd.py

@@ -0,0 +1,36 @@
+#!/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 pymaa as maa
+
+# This example will change the LCD backlight on the Grove-LCD RGB backlight
+# to a nice shade of purple
+x = maa.I2c(0)
+x.address(0x62)
+x.writeReg(0,0)
+x.writeReg(1,0)
+x.writeReg(0x08,0xAA)
+x.writeReg(0x04,255)
+x.writeReg(0x02,255)
+