Greetings! I recently got back on working on ESP01 again, since I found couple of chips in my old component box. But I have completely forgotten how I once used it.
The very first confusing thing for me was the LEDs on it. One red and the other one is blue. I know red is for Power and what does the blue LED signifies and what are its indications?
To get it to working I made a rough circuit where I can add my esp01 along with the my atmega328 chip and program it using the same ftdi chip. I have attached the schematics of it.
Now, when I make the following connections of my esp01, the Blue LED turns off
ESP01 CH_PD -> 3.3V
ESP-GPIO0 -> GND
ESP-Rx -> FTDI Tx
ESP-Tx -> FTDI Rx
so is that normal behavior? or I made some mistake?
I'm not quite sure what it is you are doing. I suspect you are putting it in programming mode, but not actually programming it.
You are clearly doing it the hard way. To program the ESP-01, the best way by far is to use the purpose-built USB programming adapter:
Aliexpress item
Similarly, to actually use the ESP-01 in a project, a very convenient way is with the cheaper adapter board, plugged into a USB "phone charger" so you have both the 5 V and 3.3 V conveniently supplied.
Aliexpress item
You have three GPIO conveniently available by soldering to the adapter, and the fourth - serial Rx - can be separated from the USB chip if necessary by cutting a track
