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?

Answer 1

Looks like your connection is somewhere missing.

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

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!