ESP is not responding (ESP 01)

[Kenan_Demir]

Connections:
ESP8266 -----> UNO:
RX -----> pin2
VCC -----> 3.3V
CHPD -----> 3.3V
GND-----> GND
TX -----> pin3

Code : https://examples.blynk.cc/?board=Arduino%20Uno&shield=ESP8266%20WiFi%20Shield&example=GettingStarted%2FVirtualPinRead&auth=xN3sm1zNfzTRpckSUrTU4u4NiKDjMmRb

Output:
[9]
v0.6.1 on Arduino Uno

[517] Connecting to AndroidAP4885
[1531] ESP is not responding

[PeteKnight]

Are you using the linked code exactly as it is in the example (with the addition of SSID, Password and Auth Code of course) or have you made any changes?
The code won’t work for the Uno as it stands, as you’ll see from the comments in the code.

Please post your EXACT code, minus your credentials.

ETA, having looked at your wiring in more detail, it seems that you are using the UNOs Rx and Tx pins, which you can’t do with this code example. See this explanation of why:

Sim900a modem cannot init

The UNO has one physical serial port, which is connected to pins 0 and 1, and also to the USB connector via a TTL to serial chip. This is the port that you are using to upload code, and to view your debug messages in your computers serial monitor. You cant use this same hardware port for talking to a device like your SIM900 board, as the data meant for the serial debug monitor would get mixed-up with the commands being sent to the SIM900 - a bit like tow phone conversations taking place on the…

Pete.

[Amorphous]

It’s been a while since I’ve used an ESP-01 as a shield but I think you need to reverse your TX and RX pins so that TX of Uno is going to RX of ESP-01 and vice versa. Pins 2 and 3 should be fine to connect to the ESP serial pins as long as you uncomment the software serial lines. I think you also need to make sure you keep the ESP-01 RX pin at 3.3v. A voltage divider is OK but a logic level converter is better. I’ve also had better results with a lower baud rate for the communication to the ESP like 9600.

Good luck! Using the ESP-01 as a shield is finicky. It’s way easier to do stand-alone 8266 with more pins like a Wemos D1 Mini or similar. And the clock speed is way faster than an arduino uno.