nRF9160 examples in NCS, the MQTT publish payload now with a pre allocated buffer, is it possible to support streaming payload to save memory usage for large payload publish.
Q1: does current NCS release (modem firmware 1.2.3, or 1.3.0) support publish >20KBytes payload in 1 single message?
Q2: is it possible to publish >20K bytes with data streaming to socket instead with pre allocated buffer in RAM?
One more questions on the large data upload options.
Do you know any limitations with HTTP or HTTPS to stream large payloads (over 20K) to server with current NCS libraries/examples.
Looking at Zephyr's HTTP client library, it seems it is able to stream large payloads by using a callback function to request data.
You can see the API in action in Zephyr's http_client sample https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.5.0/zephyr/samples/net/sockets/http_client/README.html
Note that the sample has not been tested on the nRF9160, and might need some modifications to run on the nRF9160.