Espressif ESP32 (ThingPulse) board and Mifare RC522 RFID SPI Reader to track employees coming and going from the office. Could be used as In/Out board, but these days it will be used for keeping track of a possible COVID-19 infected person visiting a site.

The ESP32 listens on the SPI interface for a card to be swiped. When a card is detected, it connects to Wi-Fi using either regular or enterprise authentication and sends a specially-crafted HTML message to a web server that then stores the UID of the card in a SQL database with a timestamp and location for later reporting and alerting.

Although developed with the ThingPulse dev board with the intention of having low-power battery-operated LiPo supply, the code also works with ESP8266 (NodeMCU 0.9 tested); also for either regular or enterprise Wi-Fi connections.

Free and open source software. MIT license.