Error in sending AT commands in esp8266 connecting to arduino IDE

Question

I am working on esp8266 with Arduino.

I have connected pins like arduino-esp 3.3-vcc gnd-gnd 3.3-CH_PD RX-TX TX-RX and reset to gnd using 3k resistor.

I couldn't send AT commands in serial monitor in Arduino IDE.

Later I connected a capacitor between Vcc and Gnd. Now I could send AT commands and I am getting same commands back. Whatever I entered, I am getting the same back.

I didn't get reply as OK. And I got some random characters too. Can anyone help me with this?

• Gerben: I think TX needs to go to TX and RX to RX, if you are sending the command via the computer instead of the arduino-sketch. You also need to convert the 5v to 3.3v on the RX line.
• Nick Gammon: You also need to convert the 5v to 3.3v on the RX line. - s/he needs to do what?
• Nick Gammon: I have connected pins like arduino-esp 3.3-vcc gnd-gnd 3.3-CH_PD RX-TX TX-RX and reset to gnd using 3k resistor. - you connected what to what? This is very unclear. Please edit your question and clarify what you have done. Also try to write proper English if possible. Sentences start with a capital letter.

Answer 1

Looks like your connection is somewhere missing.

Connect CH_PD and reset pin to high--i.e. 3.3v.

• Anonymous Penguin: Please do not insert advertisements into your post. You are welcome to add this to your profile page, but not into the post itself. I've edited it out. Thanks!

Answer 2

I made the following connection with Arduino Mega 2560 and AT commands was working perfectly well.

Connection:

ESP8266 - Arduino Mega 2560

Vcc, CH_PD, RST - 3.3V pin

GND - GND

Rx - Tx(18)

Tx - Rx(19)

Program:

void setup() {
 Serial.begin(115200); // USB serial port of Due (PROGRAMMING)
 Serial1.begin(115200); // ESP8266 on Serial Port 1 of Due (UART 1)
}
char rx_byte = 0;
void loop() {
 // send terminal byte to ESP8266
 if (Serial.available() > 0) {
 rx_byte = Serial.read();
 Serial1.print(rx_byte);
 }
 // send ESP8266 byte to terminal
 if (Serial1.available() > 0) {
 rx_byte = Serial1.read();
 Serial.print(rx_byte);
 }
}

Select Tools>Board> Arduino/Genuino Mega or Mega 2560. Upload the code. In serial monitor, select 115200 baud rate and Both NL & CR option. Enter the AT command and it works!