Wait for AT response

[awneil]

@Briga

use semaphoring. Ask for IMEI set the semaphore red. TCP routine will check the semaphore and if it is red will wait and check again.

That’s basically a state machine; with the semaphore encoding just 3 states - red, yellow, and green.

Good paper on Event-Driven Programming

Open-AT is an Event-Driven system, and many newcomers find this concept hard to grasp. I recently found this paper which gives a good description of Event-Driven programming in general (nothing specifically to do with Open-AT): Event-Driven Programming: Introduction, Tutorial, History Stephen Ferg, January 2006. eventdrivenpgm.sourceforge.net/ The Headerless Handlers and Observer patterns are particularly applicable - and the paper gives a good illustration of the “Subscription” metaph…

It would probably be better to use more meaningful state names; eg IMEI Requested, IMEI Not Available, IMEI Available.