But what if all you have on hand is an ESP8266? [TechColab] needed to control a solenoid valve with a short pulse via a solid-state relay (SSR) but found that the trusty 555 timer was tricky to ...

Instead of buying a new thermostat he and his friend [Doug] set out to build an Arduino-based controller ... to power the logic circuitry and a solid state relay to handle the load switching ...