ETHEL is an Arduino based system for remotely detecting and reporting on status of traffic congestion
Useful resources during development:
Power saving:
https://blog.adafruit.com/2012/03/27/ask-an-educator-is-there-a-way-for-an-arduino-to-turn-itself-off/
http://interface.khm.de/index.php/lab/interfaces-advanced/sleep_watchdog_battery/
https://www.instructables.com/id/Enable-DeepSleep-on-an-ESP8266-01/
Wifi:
https://medium.com/@cgrant/using-the-esp8266-wifi-module-with-arduino-uno-publishing-to-thingspeak-99fc77122e82
https://fullyloadedgeek.com/2016/01/31/esp8266-ifttt/
http://www.instructables.com/id/Add-WiFi-to-Arduino-UNO/
Posting to Twitter:
https://randomnerdtutorials.com/posting-a-tweet-with-the-esp8266
http://www.instructables.com/id/ESP8266-to-IFTTT-Using-Arduino-IDE/
Doing away with the Arduino board:
https://www.arduino.cc/en/Tutorial/ArduinoToBreadboard