Guys I need help with my esp8266. I initially uploaded a blink program from examples and now I am not able to send at command via arduino . The blue led of esp is always on. What should I do?
Sounds like you replaced the code that interprets the AT command set with the code for the blink program. You might try the instructions here: https://www.allaboutcircuits.com/projects/update-the-firmware-in-your-esp8266-wi-fi-module/
If you flash code on the ESP8266 itself, you are replacing the firmware providing the AT-commands. Either you have to flash back the AT-firmware, or you need to create your own code, that responds to commands coming from the serial-port.