htu21d: add js and py samples, put sensor on known limitations list

Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

docs/knownlimitations.md

@@ -53,11 +53,11 @@ such sensors and known workarounds if they exist.
  * **Grove BLE** (HM-11) does not return data on the Intel Galileo board due to
  known UART limitation.
  * **Grove Hall Sensor** (A11X) if the base shield is set to 3V on Intel Edison,
- it will trigger continous callbacks when the sensor is not reading anything.
+ it will trigger continuous callbacks when the sensor is not reading anything.
  * **Grove RTC** (DS1307) is not compatible with the Intel Edison Arduino board
  but will work with the Mini-breakout.
- * **Grove Tempture & Humidity (High-Accuracy & Mini) Sensor** (TH02) only works
- with the Intel Edison Arduino board when powered from the 3.3V rail.
+ * **Grove Temperature & Humidity (High-Accuracy & Mini) Sensor** (TH02) only
+ works with the Intel Edison Arduino board when powered from the 3.3V rail.
 
 #### Adafruit Sensors
 
@@ -78,6 +78,8 @@ This affects the **DS18B20**, **DS2413** and **DFREC** drivers.
 
 #### Other Sensors
 
+ * **HTU21D** is unstable on the Intel Edison with the Arduino breakout and
+ will throw an error when it can't complete an update call.
  * **MLX90614** is not compatible with the Intel Galileo due to the inability
  to change the I2C bus speed to 100 KHz.
  * **MICSV89** is not compatible with the Intel Galileo due to the inability to

examples/javascript/htu21d.js

@@ -0,0 +1,45 @@
+/*
+ * Author: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
+ * Copyright (c) 2017 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.
+ */
+
+//Load the library
+var upm = require('jsupm_htu21d');
+
+//Create a sensor instance
+var sensor = new upm.HTU21D(0);
+
+//Update sensor data and print the values every second
+var ival = setInterval(function () {
+    sensor.sampleData();
+    console.log("Relative Humidity: " + sensor.getHumidity() + "%");
+    console.log("Compensated RH: " + sensor.getCompRH() + "%");
+    console.log("Temperature: " + sensor.getTemperature() + "C");
+    console.log("Dew Point: " + sensor.getDewPoint() + "C");
+}, 1000);
+
+//Clear interval and exit on ^C
+process.on('SIGINT', function()
+{
+    clearInterval(ival);
+    process.exit(0);
+});

examples/python/htu21d.py

@@ -0,0 +1,43 @@
+from __future__ import print_function
+# Author: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
+# Copyright (c) 2017 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.
+
+from time import sleep
+from upm import pyupm_htu21d as htu21d
+
+def main():
+    # Create an I2C sensor object
+    sensor = htu21d.HTU21D(0)
+
+    # Loop indefinitely, updating data and printing values
+    while True:
+        sensor.sampleData()
+        print("Relative Humidity: %f %%" % sensor.getHumidity())
+        print("Compensated RH: %f %%" % sensor.getCompRH())
+        print("Temperature: %f C" % sensor.getTemperature())
+        print("Dew Point: %f C" % sensor.getDewPoint())
+
+        # Sleep for 1 s
+        sleep(1)
+
+if __name__ == '__main__':
+    main()