coolwolf / 28/07/2019

ESP201 Usable NodeMCU Pins

I just bought ESP-201. Then i flashed nodemcu firmware and boot the chip. When i started to write my first lua script, i see the pin numbers shown on ESP-201 pdf and other sources on the internet does not match with my chip. Then i made some tests to found which pin is which.

As you can see on the picture above, we have 6 pin’s usable as input/output on ESP-201 (If anyone has more knowledge, comments are welcome)

As you may already know, we can not use IO0 and IO2 on esp chips. They are used for boot mode selection.

But IO0 and IO2 shown on ESP-201 layout are on right place. I use them to flash firmware and boot normally. Also RX/TX and other pins needed to boot are okay.

print(“GPIO 0:”,

The problem began when i try to use these lua commands:

I try each pin and found they differ for nodemcu. I marked them on the picture above. gpio0 is XPD/IO16 pin, gpio1 is IO5 pin etc.

I hope this helps other peoples trying to use ESP-201 with nodemcu/lua