A PC817 optocoupler drives the relay control MOSFET (2N7002) With the default system setup, the relay is prone to flicking during powerup; ... In order to use the ESP-01 Wi-Fi relay module, a ...

It’s been less than a year since the ESP8266 WiFi Module was released. This is a chip whose original data sheets were only available in Chinese, could only be controlled through AT commands, … ...