ESP8266 Community Forum

Connection are as follows:
ESP8266-01 --------> ARDUINO UNO
VCC --------> 3.3 V
CH_PD --------> 3.3 V
GND --------> GND
RX --------> RX
TX --------> TX
Also reset PIN of UNO is connect to GND.
Issue:
I have connected all connections as given above except CH_PD pin. And when I connect USB cable to PC everything works fine and LED in ESP glows red. But as I connect my CH_PD pin to 3.3v pin of Arduino Uno. ESP-01 led goes off and Arduino get disconnected from my PC. I also can't see Port options in Arduino IDE.

My research till now:
I have searched everywhere for this issue but couldn't get satisfactory answer. As far as I can remember, in some video a guy was talking about this as a software issue where he was explaining that these module are manufactured in different countries. One which is manufactured in China need a additional software to be installed for its working. But unfortunately I can't remember clearly what software he was referring.
PS: Ignore my research you haven't got any idea after reading this.

Mmm, you need to read up more on both boards. Are you powering the Uno from the ESP? 3V3 pin of the Uno is an output, not an input for power. You need to sort out the power before proceeding.

Get a level shifter. ESP8266 is 3.3V, Arduino is 5V. Many ESP8266 are not 5V tolerant.

Via the level shifter cross the serial lines, i.e. rx (esp8266) to tx (Arduino) and tx (ESP8266) to rx (Arduino).