[Pete] was building a hot tub controller, using a WEMOS board based on the venerable ESP8266. After assembly, the board was plugged into USB and [Pete] hit the flash button. No dice. Investigation … ...

Of course, you’ll use the usual language you use on the ESP8266 — [Acrobotic] uses C++ in the Arduino IDE. On the browser side you’ll use JavaScript, although that will be embedded in your ...