I took me a while to get MQTT subscribe working, i'm always surprised how sparse M5's documentation is. This company would do so much better with more samples and better documentation. The hardware and price is great but it lacks a certain degree of details.

Anyway, hereby a working sample with a EMQX MQTT broker which we setup on our own server with elast.io.

We tested the sample and it works. The trick for Subscribe was using MQTT apply for messaging in the Loop. Without that it wont't work.

See the blog

Next problem is getting some code to be able to change WIFI credentials on the fly without needing to burn an image again. What happened to WIFI Smart Config?

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