Arduino Asterisk y SIP code

I read the conversation and looked at all the examples in this link Let arduino ring phones via SIP - #37 by joshuabrand1
I understand that you have not been able to register an Arduino on an Asterisk switchboard using the SIP protocol. Correct?
I have tested your examples and my asterisk on female authentication errors, etc ...
What I want to do is that if someone calls the extension I have configured on my arduino, it will be able to turn on an LED for a few seconds and hang up the call.
Sure the idea of using "AGI coder (Asterisk – nerdybynature)" might work for me, but don't follow the example and steps to do. Does anyone know of any good and clear script to be able to follow.
Thank you so much.