ESP8266 not working properly

Question

It's the first time I use an ESP8266 and I didn't manage to get a proper response in the Arduino serial monitor. I only see weird characters, when I move the 3.3V wire.

You can see the connections in the following picture:

The code I run is the following one:

#include <SoftwareSerial.h>
SoftwareSerial BT1(3, 2); // RX | TX

void setup()
{
    Serial.begin(115200);
    BT1.begin(115200);
}

void loop()
{
    String B= ".";
    if (BT1.available())
    {
        char c = BT1.read();
        Serial.print(c);
    }
    if (Serial.available())
    {
        char c = Serial.read();
        BT1.print(c);
    }
}

Maybe it's something really stupid. I am a total beginner, so I appreciate any help.

EDIT: I think power supply is 3.3V

SOLUTION: the problem was the power supply. I tried exactly the same using the 3.3V from the arduino instead of the power supply and it works perfectly!

Code Gorilla · Answer 1 · 2017-09-14T12:47:16.107

You may well have killed the ESP by supplying it 5v, you have to have a logic level shifter, as Juraj says.

Assuming it's not dead then your next problem is there have been posts about that hardware setup and SoftwareSerial doesn't work at high speed. I can't tell you what it is that doesn't work because turning the speed of the link cures the problem, try 9600 maximum.

[Edited to be less accusational, which was not the original intent]

[Update]

Please see the datasheet here: https://www.mikrocontroller.net/attachment/231858/0A-ESP8266_Specifications_v4.pdf

The table in section 8.4.4 says that the maximum input voltage is 3.6V Just after that it says all digital pins are "protected from over-voltage with a snap-back circuit". This snap back voltage is typically 6V. So does that mean the GPIO are safe up to 6V?

(It might be that this datasheet has been superseded, I am unable to access the EspressIF site at the moment).

score -1 · Answer 2 · answered Nov 26 '17 at 19:04

Step 1: Turn On Your ESP8266 Module by Using Arduino Nano 3.3V Dc Output Pin. Remeber sometimes Arduino board is not delivering sufficient voltage to the ESP8266 module. You can use a 3.3 V ( Do not exceed input voltage from 3.3v) regulator ( AMS1117 ) to power this module. A voltage divider circuit is used to drop the Arduino 5V to ESP8266 3.3 V.

Step 2: Here is the schematic Diagram, in my code I used Digital pin 2 as a Tx and D3 as an RX.

Click Here for Necessary At Commands

ESP8266 not working properly

2 Answers2