I have a working system based on the excellent MQTT article and spreadsheet.
I can send the data via hex packets to publish and subscribe to topics on CloudMQTT and Ubidots. I can test using MQTTlens. It all works perfectly.
I am using PIC24FJ64 and a SIM5300E (though plan to change to SIM868 for cost reasons)
Now my customer gives me some extra problems. They want a more professional implementation of MQTT (CloudMQTT works for me but their servers have been unreliable and the documentation is poor).
Also the customer is not familiar with the connection at his side (servers) and MQTT brokers. In fact they do not like the idea of a 3rd party broker.
They have asked if it is possible to use Google IoT
But already I see things that I do not recognise like JWT web tokens for the password:
Is this possible to achieve? Perhaps it is too much to ask from the low cost module and the microcontroller in C?
Thank you in advance for any help.