I am trying to send AT commands to ESP8266 to get connected with internet with the Wifi.

When I am sending AT and AT+RST command on serial monitor then I am getting OK and ready response which seems perfect.

Then I am sending AT+CWLAP to get list of available wifi networks which is also executing correctly.




Then I sent AT+CWMODE? which is also perfect.




Now I am trying to connect ESP8266 with above listed Wifi with this command, it is sending an ERROR on serial monitor.





Can anyone suggest me what could be the reason of this issue ?at


3 Answers 3


The source of such problems are mostly as under

  • Bad / loose wiring (power and communication)
  • software serial is not much reliable
  • Arduino serial monitor is not a user friendly way of testing out ESP modue

To solve wiring related problems for good check out this design.

To solve communication monitoring problems check out this solution

Use USB to TTL interface to connect ESP module directly to your PC without using an Arduino (find details here)


Based on the gibberish echo, the possible causes are:

  • Insufficient power. You need a source that can supply up to 300mA which is about the max consumption for the module. A good-sized capacitor across the ESP power rails (10uF maybe) wouldn't hurt.
  • Baud rate is too high. If you're using an Arduino as 'middle-man' and talking to the ESP8266 through a SoftwareSerial port, you're likely to face this sort of issue if the baud rate is as high as 115200; SoftwareSerial is unreliable at such rates.
  • I connected VCC and CH_PD to 3.3 V, should I connect GPIO0 and GPIO1 also to 3.3 V ? and ESP8266 baud rate is 9600
    – N Sharma
    May 6, 2017 at 4:22
  • I connected GPIO0 and GPIO1 to 3.3V and your solution is not working :(
    – N Sharma
    May 6, 2017 at 15:21
  • @Williams What solution? I didn't mention GPIO pins. I asked you to provide a better power source to it or reduce the baud rate. Which did you do? May 6, 2017 at 15:34
  • My baud rate is already 9600 and VCC and CH_PD to 3.3 V. How I can provide better power? can you please suggest
    – N Sharma
    May 6, 2017 at 15:36
  • @Williams How are you powering it at the moment? May 6, 2017 at 15:37

Alright! I just tried to connect with different wifi and it got connected with it. It was some kinda issue with mobile hotspot.

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