ESP 8266 is a tinny WiFi module, normally it requires the USB to serial converter to upload the programs. In this post we are going to see, how to program the ESP 8266 with out USB to serial converter. Here we are going to use the Arduino IDE and Arduino Uno board to program the tinny WiFi module. Hardwares required ESP 8266 - 01 Arduino Uno ESP demo board (Optional) Jumper wires LED with Resistor (220 / 330 ohm) Softwares required Arduino IDE What is ESP demo board and why it is required ? As you aware the ESP 8266's operation voltage is 3.3V but the Arduino is working in 5V. So the direct connection of RX and TX PINS between the Arduino and ESP is not recommended. In some cases, It breaks the ESP, So we need to step down the 5V RX, TX PINS to 3.3V as well as for 5V power supply. The ready made ESP demo board offers this functionality to us. Otherwise we have to add the resistors between the RX and TX to step down the voltage. How to con...