Page 1 of 1

ESP-WROOM-02 - Startup Problem (Beginner)

Posted: Sun Feb 26, 2017 10:46 pm
by MrMartini83
Hello all,
i was allready working successfully with my ESP8266 ESP 01, but now I want to use the ESP WROOM 02 because of the FCC & CE Listing of this device. I use it for a shool final project where I have to connect it to an ATMEGA 328 and I need to be able to communicate by AT Commands. So everything was working quit well with ESP 01 but now, when I move to the WROOM device I'm getting problems. No successful return values!

I made a very simple test project for my arduino board where I can send and receive commands in my RealTerm Terminal on the PC, and the Ardunio is acting as "UART relay station". - It is working well when I switch back to ESP 01.

So I tested the buadrate of 115200 which is mentoid in the help file for AT commands but I always get only multiple 0xFF as return values.
I try to sent AT as my first test but it won't work.

Below a drawing of my wiring - maybe someone is so kind and help me.

Thank you, and best regards from Europe / Austria!


Connection Diagramm:


Re: ESP-WROOM-02 - Startup Problem (Beginner)

Posted: Mon Feb 27, 2017 7:25 pm
by ESP_Xutao
ESP 01 is't our official model,so i am not familiar with this model.About WROOM 02,So i don 't you how control it,you can consult this Doc. ... eet_en.pdf

Re: ESP-WROOM-02 - Startup Problem (Beginner)

Posted: Wed Feb 21, 2018 10:40 pm
by kzsolt2
Dear Beginner!

WROOM is littelbit complicated than ESP-nn board, but provide better performance.

Consult "ESP8266 SDK Getting Started Guide" chapter "2.2. ESP-WROOM-02" for correct wireing.

Do you need to pull up and pull down more pins.
For first try I recomend to use 330Ohm serial resistor for RXD and TXD.
According my experince TXD of MCU need to be connect TXD! pin of ESP-WROOM-02.

The ESP-WROOM-02 is delivered with AT firmware.

kzsolt2 8-)