bmp85.js: add i2c read/write example

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

examples/javascript/bmp85.js

@@ -0,0 +1,55 @@
+#!/usr/bin/env node
+
+/*
+ * 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.
+ */
+
+var m = require('mraa'); //require mraa
+
+// helper function to go from hex val to dec
+function char(x) { return parseInt(x, 16); }
+
+x = new m.I2c(0)
+x.address(0x77)
+
+// initialise device
+if (x.readReg(char('0xd0')) != char('0x55')) {
+  console.log("error");
+}
+
+// we want to read temperature so write 0x2e into control reg
+x.writeReg(char('0xf4'), char('0x2e'))
+
+// read a 16bit reg, obviously it's uncalibrated so mostly a useless value :)
+console.log(x.readWordReg(char('0xf6')))
+
+// and we can do the same thing with the read()/write() calls if we wished
+// thought I'd really not recommend it!
+buf = new Buffer(2)
+buf[0] = char('0xf4')
+buf[1] = char('0x2e')
+console.log(buf.toString('hex'))
+x.write(buf)
+
+x.writeByte(char('0xf6'))
+d = x.read(2)