Say, you’re starting your electronics journey with a few projects in mind. You have an ESP8266 board like the Wemos D1, a Li-Ion battery, you want to build a small battery-powered sensor that ...

This pin is on the rear of the ESP8266 module, and on many development boards, it isn’t even connected. That’s because its internally hooked up to the ESP8266’s SPI flash chip, and using it ...