Also it is pretty easy to make your own programmer, or you can program the ESP-01 module with the help of the Arduino IDE ... open your web browser and type 192.168.4.1 in the address bar. You can ...

In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board, one 1K and one 10K resistors, 1 BC547 transistor, one 6V or 12V relay, one 1N4007 diode and a 12V fan ...