Arduino Mega + ESP12-E - No response to AT commands

Projects Networking, Protocols, and Devices
1

Hello everybody,

I have some issues with communicating to my ESP-12-E using solely an Arduino Mega 2560 and the Arduino IDE.

Here is how I connected everything:

ESP12 --------------- Arduino Mega

Tx -------------------- Rx3
Rx ----VD to 3.3V---- Tx3

The Arduino is powered by USB, the ESP12 with an external power supply at 3.3V.

Connections of the ESP

Vcc ---------- 3.3V
EN(CH_PD)--- 3.3V
GPIO0 ------ 3.3V
Gnd ---------- Gnd
GPIO15 ------ Gnd

Arduino and power supply share a common ground.

The code I am using in the Arduino IDE is the following:

void setup(){
Serial3.begin(115200);
Serial.begin(115200);
}

void loop(){
if (Serial3.available()) Serial.write(Serial3.read());
if (Serial.available()) Serial3.write(Serial.read());
}

When I power up the ESP12 and the Arduino, the Serial monitor gives the following output:

Ai-Thinker Technology Co.,Ltd.

ready

However, if I enter "AT" or "AT+RST" nothing happens. The TX LED on my Arduino blinks when entering a command. Also, the ESP12 is up running since I'm able to find its wifi.

What am I doing wrong?

2

suschi:
Hello everybody,

I have some issues with communicating to my ESP-12-E using solely an Arduino Mega 2560 and the Arduino IDE.

Here is how I connected everything:

ESP12 --------------- Arduino Mega

Tx -------------------- Rx3
Rx ----VD to 3.3V---- Tx3

The Arduino is powered by USB, the ESP12 with an external power supply at 3.3V.

Connections of the ESP

Vcc ---------- 3.3V
EN(CH_PD)--- 3.3V
GPIO0 ------ 3.3V
Gnd ---------- Gnd
GPIO15 ------ Gnd

Arduino and power supply share a common ground.

The code I am using in the Arduino IDE is the following:

void setup(){

Serial3.begin(115200);
Serial.begin(115200);
}

void loop(){
if (Serial3.available()) Serial.write(Serial3.read());
if (Serial.available()) Serial3.write(Serial.read());
}




When I power up the ESP12 and the Arduino, the Serial monitor gives the following output:

However, if I enter "AT" or "AT+RST" nothing happens. The TX LED on my Arduino blinks when entering a command. Also, the ESP12 is up running since I'm able to find its wifi. 

What am I doing wrong?

Where are you getting the 3.3V? Verify your 3.3 voltage. The ESP can consume over 150mA.

It might be browning out.

Chuck.

3

The problem was that I used some additional capacitors for my voltage regulators. Removing these on the TX (Arduino) to RX (ESP) line solved the problem.