Max topic length about pubsubclient

[knolleary]

Hi - what do you call long?

As documented, by default, there is an overall limit of 128 bytes for any packet sent or received. This can be increased by changing the MQTT_MAX_PACKET_SIZE #define in PubSubClient.h

[gitmaster2013]

Thanks for the quick reply!
So I guess that means there is just the adjustable 128 bytes limit. I found the MQTT_MAX_PACKET_SIZE, but I am having trouble subscribing to topics longer than 23 characters. I checked that the over all message is less than 128 bytes. I am having trouble locating my problem. Could it be the Arduino running out of me memory?

[knolleary]

By "not working", can you describe what you mean? Is it simply that the messages don't arrive, or does the entire sketch fail to work?

It would useful to confirm if the sketch is otherwise running happily - that would rule out memory issues, otherwise the sketch would be continually resetting.

[knolleary]

@gitmaster2013 any news on this or can I close the issue?

[gitmaster2013]

Sorry for the holdup! I found a workaround for the problem. I assume there was a RAM overflow of some kind. The Mega32 just didn't seem to have enough power. Thanks for checking back with me!

[knolleary]

Thanks for the update - closing the issue.