# ESP8266 AT command is not working through andrino uno **URL:** \ **Category:** Networking, Protocols, and Devices\ **Created:** [May 13, 2018, 4:48pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876 "2018-05-13T16:48:24Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![pramodgopinathan](https://avatars.discourse-cdn.com/v4/letter/p/4af34b/32.png) [@pramodgopinathan](https://forum.arduino.cc/u/pramodgopinathan)\ **Post date:** [May 13, 2018, 4:48pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/1 "2018-05-13T16:48:24Z")
Hi, I am trying to connect ESP8266 via andrino uno while checking serial monitor. It showing blank. Please find configuration: Andrino TX -\> ESP8266 RX Andrino RX -\> ESP8266 TX Andrino 5v -\> I have made power supply model using capacitor and regulator 3.3 v -\> VCC and CH\_PD Power supply model GND -\> ESP8266 GND Also i have tried Andrino GND -\> ESP8266 GND I have attached the model. Wifi is detecting but none of the AT commands are working. Hope you could help me. Thanks Pramod ![IMG_3773.JPG](https://europe1.discourse-cdn.com/arduino/original/4X/7/e/7/7e7d8936893a01d914a5c31a458b778a85361979.jpeg) ---
**Author:** ![ieee488](https://avatars.discourse-cdn.com/v4/letter/i/d2c977/32.png) [@ieee488](https://forum.arduino.cc/u/ieee488)\ **Post date:** [May 13, 2018, 6:55pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/2 "2018-05-13T18:55:55Z")
Which Arduino? Which ESP8266 module? . ---
**Author:** ![agrp87132](https://avatars.discourse-cdn.com/v4/letter/a/cdc98d/32.png) [@agrp87132](https://forum.arduino.cc/u/agrp87132)\ **Post date:** [May 13, 2018, 7:00pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/3 "2018-05-13T19:00:55Z")
For the hardwired serial pins it is Tx to Tx and Rx to Rx. It looks like you are using an Uno and Esp-01 ---
**Author:** ![pramodgopinathan](https://avatars.discourse-cdn.com/v4/letter/p/4af34b/32.png) [@pramodgopinathan](https://forum.arduino.cc/u/pramodgopinathan)\ **Post date:** [May 13, 2018, 7:06pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/4 "2018-05-13T19:06:27Z")
Thanks. Yes Arduino Uno and esp01 is the model. I already tried TX to TX and rx to rx ... still no success .. ---
**Author:** ![ieee488](https://avatars.discourse-cdn.com/v4/letter/i/d2c977/32.png) [@ieee488](https://forum.arduino.cc/u/ieee488)\ **Post date:** [May 13, 2018, 7:09pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/5 "2018-05-13T19:09:30Z")
[http://www.martyncurrey.com/arduino-to-esp8266-serial-commincation/](http://www.martyncurrey.com/arduino-to-esp8266-serial-commincation/) ---
**Author:** ![agrp87132](https://avatars.discourse-cdn.com/v4/letter/a/cdc98d/32.png) [@agrp87132](https://forum.arduino.cc/u/agrp87132)\ **Post date:** [May 13, 2018, 7:44pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/6 "2018-05-13T19:44:41Z")
What is that voltage regulator you are using? It does not look like an ams1117. The ams1117 is tiny, that looks huge. Read Martyn Currey's blog as suggested, you can try the 3.3v pin on the Uno, but it is preferred esp-01 have its own power supply. 115200 default baud rate both NL and CR on serial monitor And Tx to TX, Rx to Rx for hardwired serial, pay more attention to arrows on Uno than the labels ---
**Author:** ![pramodgopinathan](https://avatars.discourse-cdn.com/v4/letter/p/4af34b/32.png) [@pramodgopinathan](https://forum.arduino.cc/u/pramodgopinathan)\ **Post date:** [May 14, 2018, 3:03am UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/7 "2018-05-14T03:03:28Z")
Its 1117 not AMS but different brand. I have checked the V with the help of digital multimeter and power show is 3.3 v. Let me try adding 10K resistors to TX pin because arduino is 5v and ESP8266 is 3.3v. **you only need the voltage divider on the Arduino TX pin. The 5V Arduino will read 3.3v as HIGH so you can connect the ESP8266 TX pin directly to the Arduino RX pin.** ---
**Author:** ![pramodgopinathan](https://avatars.discourse-cdn.com/v4/letter/p/4af34b/32.png) [@pramodgopinathan](https://forum.arduino.cc/u/pramodgopinathan)\ **Post date:** [May 14, 2018, 4:09am UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/8 "2018-05-14T04:09:38Z")
I have put 2K ohm between TX ESP8266 to TX Arduino. Still AT is not working and i am not able to upload code. Error code: warning: espcomm\_sync failed error: espcomm\_open failed error: espcomm\_open failed attached pics for design. Thanks Pramod ![IMG_3798.JPG](https://europe1.discourse-cdn.com/arduino/original/4X/9/6/4/96440b4296d3a948cca4f4c0aff18242bf5407b7.jpeg) ---
**Author:** ![agrp87132](https://avatars.discourse-cdn.com/v4/letter/a/cdc98d/32.png) [@agrp87132](https://forum.arduino.cc/u/agrp87132)\ **Post date:** [May 14, 2018, 4:10pm UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/9 "2018-05-14T16:10:53Z")
That's not how you make a voltage divider. If you cannot figure it out, I suggest you order some of these handy things from ebay. Google 5v to 3.3v TTL voltage divider ![s-l1600.jpg](https://europe1.discourse-cdn.com/arduino/original/4X/c/4/3/c43acbd53fb7cb8312a90de69cb5eecbc1afcec6.jpeg) and Error code: warning: espcomm\_sync failed error: espcomm\_open failed error: espcomm\_open failed why are you trying this? I thought you wanted AT commands. For that you don't even need the arduino IDE ---
**Author:** ![wargod797](https://avatars.discourse-cdn.com/v4/letter/w/ecccb3/32.png) [@wargod797](https://forum.arduino.cc/u/wargod797)\ **Post date:** [September 21, 2019, 6:50am UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/10 "2019-09-21T06:50:55Z")
I also have same trouble i am using arduino uno, AMS 1117 3.3V Regulator, esp is working but not replying any commands i think something problem with a firmware its esp8266-01 2013 Model ---
**Author:** ![nandhu123](https://avatars.discourse-cdn.com/v4/letter/n/c0e974/32.png) [@nandhu123](https://forum.arduino.cc/u/nandhu123)\ **Post date:** [November 1, 2019, 9:10am UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/11 "2019-11-01T09:10:30Z")
did the problem solved sir...as i started facing the same..someone help ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 6, 2021, 11:10am UTC](https://forum.arduino.cc/t/esp8266-at-command-is-not-working-through-andrino-uno/525876/12 "2021-05-06T11:10:50Z")