Since this is my first "quasi-professional" project that I actually
want others to use, I wanted there to be decent quality documentation
for all the functions and structs that the end user would need to use.
I had tried Doxygen before but never had much luck, mostly because
I didn't bother to put in the effort to read the documentation closely.
So this time around I did, and the output so far looks quite good
and has a lot of detail about the functions, and the two typedef
structs that are key to everything working.
Added code to check if wifi is connected before allowing the TCP
connection to be attempted. Similar code for mqtt_connect, checking
if we have a valid TCP connection to the server. Waiting for
wifi uses a new global timer. These changes affected the indentation
of huge chunks of the code, as they got wrapped in ifs.
We now take advantage of the void *reverse pointer in the espconn
struct to point to the mqtt_session_t that is active. This is a nice
touch that Espressif added, so you can access arbitrary data from
within callbacks. This will allow us to (soon) have user callbacks
to deal with MQTT messages.
Also added license notices to all the source code files.
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.
