Where to find tutorials for ESP8266 in C? I am looking for structure, timers, interrupts

Hi,

I have quite a lot of knowledge in Arduino programming. I would like to start the adventure of programming the ESP8266 module. My main goal is to use the source codes of the supla software to create my own device that I can modify fairly flexibly.

My problem is that I have not found any solid documentation or tutorials for programming the NodeMCU in c. Everything I've come across has been based on either the Arduino IDE or the classic language without using the SDK.

Is anyone able to recommend some material I can use? I am mainly concerned with program structure, timers, interrupt handling etc.

Thank you in advance.

eriq2207 wrote:

My problem is that I haven't found any solid documentation and tutorials for programming the NodeMCU in c. Everything I've come across has been based on either the Arduino IDE or the classic language without using the SDK.

.
Have you read anything about ESP-IDF?
https://docs.espressif.com/projects/esp8266-rtos-sdk/en/latest/?badge=latest
https://github.com/espressif/ESP8266_RTOS_SDK

Added after 18 [minutes]:

A 'must' read is Kolban’s book on the ESP8266:
http://neilkolban.com/tech/esp8266/