What is the maximum time i should wait for CALL/SMS ready on a SIM800L

Im using the sim800L module, and the module randomly sends "SMS READY" and "CALL READY". I have read that these are unsolicited messages meaning they really just come at anytime. To prevent it messing my further commands i would like to wait for it to arrive.

So i have tried it arriving 3 seconds after sending AT but there are times where it did not arrive at 20 seconds. I mean I cant just wait forever for it to arrive, there must be a maximum time in the datasheet, but i could not find it

Where did You read that? Have You been checking the users manual/datasheet/applications, for this?

The asynchronous messages and response times are a pain for modem apps. The newer SIMCOM modems are generally quite a bit faster, not helped by the ‘send-and-wait’ style of programming,

The FONA driver is probably the best out there, but is still blocking.

About four years ago, I hacked and mangled the FONA library to run asynchronously, but it’s not pretty. I had a need at the time!

Basically rewritten as a STATE MACHINE that is exposed to the host program.

It runs much faster and more consistently than the blocking code… sends 2-3 text messages per second, and is virtually non blocking. ~10ms worst case.

ahhh so that means im just out of luck...

Not really… you just have to analyse and understand the traffic, and make a decision what to do if ‘something’ doesn’t happen.

In my code, I wait a maximum of 15 seconds, then retry five times before resetting/reconnecting the modem, (3 cycles), and eventually abandoning that action.

This accommodates a local cell outage as well as some transmission issue.

If you use an async message queueing strategy, the send process just picks up on the next message if one happens to be lost or dropped.

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