ESP8266 Community Forum

Hi everyone,

Recently I bought 2 ESP-01S, S series. I have connected an ESP-01S to an Arduino UNO. When I open a Serial Monitor, I see:



But any AT command I give, doesn't give me any response. I tried:

- AT+RST (no response)
- changing the baud rate, 9600, 115200, etc
- swap RX/TX cables
- tried the Arduino IDE with Linux PC and a MacBook Pro with macOS
- tried different ESP-01S boards (I have 2)

Does anyone have an idea what I've to do to make it work?

did you set the line end setting in Serial monitor to "both"?

I found out what the problem was. The ESP-01S modules that I bought were flashed with ESP3D firmware, used for 3D printers. I did not know that when you buy such a module, is it not guaranteed to have the AT firmware. I flashed the module with firmware from the manufacturer Espressif. Now, all works fine.

Here is a link to the firmware for those having the same problem:
https://www.espressif.com/en/support/do ... d%5B%5D=14

I used version 1.7.4, since version 2.0 and higher needs more than 1Mb of memory.

Your ESP's don't contain AT firmware (looks like they've got ESP3D firmware installed).
You have to download the latest AT firmware (please choose the one for the ESP8266 with the amount of flash memory you have) and flash it to your ESP's.

After that you can use AT commands (but trust me: you actually don't want that).