The Raspberry checks the temperatures and controls the water tank. If the water is too colt for the bathroom, heat it up. The raspberry has solid state relays to switch the heating elements and the pump.
Projeto Integrado IV - Tema IOT Projeto consiste no monitoramento de uma planta com Arduino e sensores via Web
relay for executing on of off switches to be implemented for house's electricity
Freezer-to-Frigidaire, ESP8266 powered freezer cell periodically shut down to stay within typical refrigerator temperature range (e.g. 2 to 5°C) A DHT22 inside the freezer is polled and a 5V relay and a cascaded BIG 220v SSR are switched accordingly.