IRMQTTServer: Add TX channel support for HTTP interface.

[crankyoldgit]

• Allow "channel" (KEY_CHANNEL) argument to control which TX channel to send to.
• Update "aircon" html page to be able to selection which climate channel to use.
• Consolidate some duplicate code into genStatTopic()
• Update comments/documentation on for full multi-channel TX support.
• Fix some potential unreferenced pointer issues.

[crankyoldgit]

FYI @sheppy99
As you use the multi channel part regularly, would you mind testing this?
You should be able to select the "channel" from the "aircon" HTML page when using more than one channel.

[sheppy99]

I just tried to compile it and it failed at 1131:18 which is

sendJsonState(states[i], stat_topic + KEY_JSON);

The changes I've made to IRMQTTServer.h are:

const uint8_t kNrOfIrTxGpios = 7;
#define MQTT_CLIMATE_JSON true
#define MQTT_CLIMATE_HA_MODE false
#define MQTT_DISCOVERY_ENABLE false
#define MQTT_CLEAR_ENABLE true

[crankyoldgit]

@sheppy99 Thanks for finding that issue. Fix has been push to the branch. Please download and try it again! :)

[sheppy99]

It compiles now although it does show 2 minor errors, the first one is expected with debug disabled, is the second one relevant?

D:\My Documents\Arduino\IRMQTTServer\IRMQTTServer.ino:494:6: warning: unused parameter 'str' [-Wunused-parameter]

 void debug(const char *str) {

      ^

D:\My Documents\Arduino\IRMQTTServer\IRMQTTServer.ino: In function 'void handleAirConSet()':

D:\My Documents\Arduino\IRMQTTServer\IRMQTTServer.ino:1131:18: warning: comparison is always true due to limited range of data type [-Wtype-limits]

   if (channel >= 0 && channel < kNrOfIrTxGpios) chan = channel;

              ^

[crankyoldgit]

Technically, they are compiler warnings, not errors. Just pushed another update to fix the latter warning.

Let me know how that goes. The code should function the same.

[sheppy99]

It compiles fine and its passed a quick ON and OFF test on ac_3, ac_4 and ac_5 from both the examples page and also from MQTT. Once I realised that I had to click the change button next to the channel before the channel change took effect.
This is a great addition for troubleshooting

[crankyoldgit]

Excellent. Also pushed a change to try to fix the "debug" compiler warning too. Doesn't come up on my system, even before the change, but let me know if it fixes it too.

[crankyoldgit]

Oh, and thanks for confirming it works as expected.

[sheppy99]

The compiler warning has gone, apart from something to do with an unused variable in PUBSUBClient which doesn't break anything and has been there for a long time. I just tested 2 AC's this time and they turn ON and OFF from both the webpage and via MQTT. I also confirmed the Daikin2 on Channel 0 turns ON and OFF via MQTT with the full hex string

[crankyoldgit]

unused variable in PUBSUBClient

Yep, that's an issue in their library. Nothing I can do about that one.

Thanks for the confirmation that it's working as expected.

[crankyoldgit]

FYI, the changes mentioned above are included in the newly released version of the library (v2.6.6).