Interface NodeMCU (ESP8266) with GSM module

Question

I'm a new user of NodeMCU and I would like to make it communicate with a GSM module like SIM900. Can I use the second UART terminal of ESP8266 to interface with the GSM module?

Thanks.

Answer 1

I wrote a tutorial how to do it: http://atcommander.io/Tutorials/Name/ESPInterface

As cagdas said, essentially you use UART0 from ESP8266, remembering to switch its pins assignment to GPIO13/GPIO15 with uart.alt(1); in NodeMCU.

To receive debug messages in your computer, you won't be able to use UART0 anymore, but instead you can use UART1 from ESP8266 which is transmit only.