Arduino and the real world

• A system installed outdoors using an Arduino Mega + Ethernet shield to send DHT11 and other sensor data to a remote server
• Completed continuous 2 year operation on July 12 2021
• Server uses Linux+PHP+MySQL
• 1826506 records on the database
• Highcharts used to plot graph with data
• Average time to query MySQL table with 1.8 Millions records takes about 1 second. Server is a virtual machine at 2GHz with 4GB RAM / standard virtual hard disk. Table has only the primary key, without additional indexes
• Low cost! Parts cost was about 25 dollars
• Based (with many modifications) on: https://github.com/rafaelaroca/PHP_SimpleIOT and https://github.com/rafaelaroca/Arduino_RFID_Web_Access_Control_With_Calendar
• Today is very cold at São Carlos, the Brazilian capital of technology! 😉