ESP8266 Weather Display

Description:

This is an Arduino project that uses the cheap ESP8266 WiFi module. For more details see the blog posting: http://thisoldgeek.blogspot.com/2015/01/esp8266-weather-display.html

The sketch connects to wunderground.com and returns current weather conditions for your location every 15 minutes. The returned data is formatted as JSON. The JSON is parsed for display on a serial LCD.

Configuration:

You will need an API key (free) from http://www.wunderground.com/weather/api/d/login.html
You must install ArduinoJson in your sketchbook/libraries folder (https://github.com/bblanchon/ArduinoJson)
You must be using Arduino 1.0.6 or later for ArduinoJson library to install properly - it uses nested include statements
Change the following:
- SSID - name of your network
- PASS - password for your network
- LOCATIONID - desired geographic location for weather conditions (eg., US ZipCode, State/City, Int'l)
- YOURKEY - your API key for wunderground

LOCATIONID can be of the following forms:

#define LOCATIONID "Germany/Munich" (International)
#define LOCATIONID "94523" (US ZipCode)
#define LOCATIONID "CA/Pleasant_Hill" (US City)

Process:

Hard Reset
Connect to WiFi
Set to single connection
Set up TCP connection
Send data (GET) to wunderground
Use Serial to read the returned json (JavaScript Object Notation) pairs
Parse the key-value pairs
Display
Close the connection
Wait 15 minutes (to keep within limits of free API license)

Pro Trinket Notes Updated 01-07-2015

The Pro Trinket 3V runs at 12Mhz. SoftwareSerial (required for this project) through Arduino 1.0.6 only has a version of SoftwareSerial that supports 8, 16 and 20MHz. You will need to update the SoftwareSerial.cpp file, available here.

Instructions for updating SoftwareSerial.cpp on a Mac:

Close Arduino if running
Open a New Finder Window
Open Applications, highlight Arduino (or whatever you name your Arduino app)
Show Package Contents
Open Resources\Java\libraries\SoftwareSerial
Copy SoftwareSerial.cpp (downloaded from github) to this folder, replacing the older version of SoftwareSerial.cpp
Restart Arduino

Update April 29, 2016 for Adafruit Feather Huzzah:

This code uses the ESP8266WiFi library to do Web client calls via the Feather Huzzah. The older version in this git does straight-up serial AT Command Set calls to the ESP8266 module.

The code update here is based on Mike Rankin's ESP8266 OLED Weather Display: https://github.com/mike-rankin/ESP8266_OLED_Display