ESP8266 Community Forum

Posted: **Thu Sep 28, 2017 12:57 am**

Hi

I just received an ESP8266-01 which I ordered from SparkFun (https://www.sparkfun.com/products/13678), and I'm having a hard time verifying whether it is functioning properly. I've looked at several tutorials, and videos that go over how to connect the module to an Uno, but nothing shows up in the serial monitor for me.

I'm using an external power supply of 4x AA batteries, with a voltage regulator to give me 3.3 V. I have VCC (aka 3V3), CH_PD (aka EN), and RST connected to 3.3 V. I have the module connected to ground, and GPIO0 connected to 3.3 V. I have the RX and TX pins from the Uno connected to a level shifter, and then connect the RX and TX pins from the module to the respective pins to the level shifter. I've also tried swapping RX and TX around in case I had them mixed up.

When I supply power to the module the blue LED will do a quick blink, and then proceed to stay lit. When I connect GPIO0 to ground, and power the module, the LED goes straight to being solid without the initial blink. The LED leads me to think it has sufficient current, and then I haven't damaged it. There seems to be only 1 LED opposed to the additional red LED that every example seems to show.

When I open the serial monitor and power the module, I don't see the boot information. I've tried changing the baud rate in case that was an issue but regardless of which baud rate I select from the serial monitor nothing shows up. Needless to say, entering AT yields nothing.

Does anyone have any idea what I could be doing wrong?

Thanks

Posted: **Thu Sep 28, 2017 1:03 pm**

A fellow from the Arduino forums shared this guide with me, and I modified my connections to match the guide.
https://tttapa.github.io/ESP8266/Chap01 ... P8266.html

Here's a visual representation of the connections.

I was originally trying to connect the arduino similarly to how this and many other guides suggest, and then use the serial monitor to verify everything is working.
https://forum.arduino.cc/index.php?topic=283043.0

I was just told that I need to use the software serial library, so I found a similar thread on stackexchange with an example sketch like this.

Code: Select all

#include <SoftwareSerial.h>

const byte rxPin = 2; // Wire this to Tx Pin of ESP8266
const byte txPin = 3; // Wire this to Rx Pin of ESP8266

// We'll use a software serial interface to connect to ESP8266
SoftwareSerial ESP8266 (rxPin, txPin);

void setup() {
  Serial.begin(115200);
  ESP8266.begin(115200); // Change this to the baudrate used by ESP8266
  delay(1000); // Let the module self-initialize
}

void loop() {
  Serial.println("Sending an AT command...");
  ESP8266.println("AT");
  delay(30);
  while (ESP8266.available()){
     String inData = ESP8266.readStringUntil('\n');
     Serial.println("Got reponse from ESP8266: " + inData);
  }  
}

I tried to modify the baud rates but, when viewing the serial monitor I just see it attempting to send an AT command along with the TX LED blinking on the Uno. However I can't get any response.

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