ESP8266 Community Forum

Hi,

I need to run mqtt over TLS with mutual authentication, but I don't enough free ram, do you guys have any ideas about what I could optimise to get more ram?

Any help is much appreciated!

In order to optimize, there needs to be a starting point. How can anyone do that without knowing more about what you have done?

How about this answer. Get rid of anything you don't really need.

I'm running MQTT over TLS1.2 at the moment and have no problems, so it definitely can be done.

Have a look at the compiler settings put up in this thread and see if they help at all.

In addition you could generate a link map and see where your RAM is going

@davydnorris

Thanks for your answer.

In a simple project with no much running (only the basic) I am also able to run mqtt over TLS, I have done some tests and found that when the free heap memory goes below 38k it is not able to do the handshake anymore.

In my current project I have only 31K of free ram, so I need to get about 7K more. Before I was on non-os sdk version 2 and by upgrading to version 3 I got about 15K more RAM (which left me with 31K of free RAM in total), that is why I asked this question here to see if there is something else I could upgrade...

My first thought was to upgrade to the LWIP version that @eriksl published here, he says he got 11Kb of free ram by doing so:

viewtopic.php?f=166&t=19443&p=81960&hilit=mdns#p81960

But having a closer look to his library looks like quite a big task getting rid of all the espconn layer on my project...

@davydnorris I'll try the two thing you suggested, thanks