used as output or input / Logic-Levels: HIGH (on) or LOW (off) / HIGH Voltage is either 5V (Arduino) or 3.3V (all other) / communication with digital protocols like UART, I2C or SPI GPIO-Pins
/ bare modules are not very beginner friendly: / soldering and additional components are required / no USB interface: needs USB to UART converter to program / development boards with USB are available (nodemcu DevKit) / best option for electronics-projects you want to keep
and load-circuit are fully seperated / Switch high loads with a low control-voltage / needs additional amplification to drive the coil if used with very low power devices Magnetic Coil Switching Contacts Transistor (Amplifier) Screw Terminals
/ API modeled after node.js, provides Filesystem, GPIO, JSON, Networking and other modules for communication / very limited resources (around 25kB heap available after boot)
Rest-oriented interface for the sockets / full source-code on github: https://github.com/usefulthink/nodemcu-powerstrip http://nodemcu.com/index_en.html switching the relays connect to a network (simplified) handle http-requests (my implementation)
need a Breadboard, some jumper-wires and an idea what to do / Buy from Chinese sellers, delivery takes longer but it's way cheaper / Find people to help you or join a Hackerspace* near you How to get started? *(see