The purpose of this design is for learning how to play with the hardware and software of a IOT project, it is based on price competitive wifi module
Wifi IoT Relay Board Based on ESP8266
ESP8266 Relay Module Smart Home Phone Remote Control Switch APP ESP-01 – eElectronicParts
MODULO RELAY SWITCH DIY ESP8266 WIFI 4 CANALES OPTOACOPLADOS ⋆ Starware
ESP8266 Wireless WIFI Relay Module 1/2/4/8 Channel ESP-12F Wifi Development Board AC/DC 5V/7-28V/5-80V Power Supply for Arduino - AliExpress
ESP8266 WiFi 2 Channel Relay Module
ESP8266 WiFi 2 Channel Relay Module
ESP8266 Relay Module Smart Home Phone Remote Control Switch APP ESP-01 – eElectronicParts
Módulos wireless – Página 3 – Novatronic
DC 5V 7- 80V 30A ESP8266 WIFI 1/2 Channel Relay Module ESP-12F Development Board
WiFi - 8 Channel Relay Board ESP8266
Wi-Fi ESP8266 Relay Module For Arduino - Altronics
WiFi - 8 Channel Relay Board ESP8266