Quite a few updates. Subscription feature is now working,
which is great. This has been tested with mosquitto broker
as well as Adafruit IO, and it works perfectly with both.
I tried to compile this project as a library (see the changes
to Makefile) but when I used that .a file in another project
the linking process failed. More research needed, I've never
tried to do that before.
I compressed some of the case statements in mqtt_send as they
are so similar, it's a waste of code space to duplicate them.
Disconnect and ping are identical except for one byte, and
unsubscribe and subscribe differ in only a few lines.
The data receive callback now prints information on what kind
of packet/data was received; again, mostly useful during
debugging, but the framework is there to expand it to do
useful things like triggering other tasks/timers, etc.
There is now a keepalive ping timer which keeps both the MQTT
and thus the TCP connection alive. It currently pings every 5
seconds, though I might change that closer to the timeout
maximum (50 seconds).
Signed-off-by: A.M. Rowsell <amrowsell@frozenelectronics.ca>
After much consternation, finally got the code generalized. For
some reason the ESP8266 absolutely cannot pass pointers between
functions. I'm not sure if this is because it's a timer function?
Either way, we have to memcpy the values, which makes things a
bit messier, but not too bad.
Now to start work on Publish...
The code is now pretty messy, as I've just been hacking it
together so far. It's basically hardcoded, so the next steps
will be to parameterise everything. I also need to rethink
the data structures, and function names/structures.
I need to make this feel more like an API to be called by
a user. This will naturally help organize the functions.
