ToDo:

• Add alarm level indicator and heater switch status
• Original datasource app needs email/sms notifications at set level
• Need proper config file for app on datasource
• Add selector tool to choose which readings displayed by date
• Put data uploaded into proper SQL database
• Make date format UK style! - Difficult!! Ignores hAxis.format

Done:

• Changed code to use only last 100 or so readings (1 day + a bit)
• Data (local data file copy) and latest versions of scripts are
  backed up to Dropbox automatically at 01:57 am each day
• Added meta refresh so that chart updates every 15 minutes
• Google line chart default font is Arial!
• Text styles changed to Arial, Helvetica etc.
• It is touch screen unfriendly unless you expand screen.
  Finger tips usually select more than 1 data point!