Merge pull request #21 from foglamp/FOGL-2518

FOGL-2518 NOTE added at the end of postinst script; FileNotFoundError handling added  for import

packages/Debian/armhf/DEBIAN/postinst

@@ -33,3 +33,9 @@ set_files_ownership () {
 
 set_files_ownership
 echo "Enviro pHAT plugin is installed."
+echo "IMPORTANT NOTE: To use this plugin, it is required to enable i2C on the Pi, please do the following steps:
+1) sudo raspi-config
+2) Choose advanced options
+3) Choose I2C Enable/Disable automatic loading
+4) Follow the prompts to set this to load this automatically
+5) Reboot the Pi (optional)"

python/foglamp/plugins/south/envirophat/envirophat.py

@@ -4,16 +4,21 @@
 # See: http://foglamp.readthedocs.io/
 # FOGLAMP_END
 
-""" Module for EnviroHat 'poll' type plugin """
+""" Module for Enviro pHAT 'poll' type plugin """
 
 import copy
 import uuid
 import logging
-from envirophat import light, weather, motion       # unused: analog
 
 from foglamp.common import logger
 from foglamp.plugins.common import utils
 
+_LOGGER = logger.setup(__name__, level=logging.INFO)
+
+try:
+    from envirophat import light, weather, motion       # unused: analog
+except FileNotFoundError:
+    _LOGGER.error("Ensure i2c is enabled on the Pi and other dependencies are installed correctly!")
 
 __author__ = "Ashwin Gopalakrishnan, Amarendra K Sinha"
 __copyright__ = "Copyright (c) 2018 Dianomic Systems"
@@ -92,8 +97,6 @@
     },
 }
 
-_LOGGER = logger.setup(__name__, level=logging.INFO)
-
 
 def plugin_info():
     """ Returns information about the plugin.