B4R Question MQTT Payload() size ?

[Andrej Meszaros]

Hi,

is there a limit for sending Payload in MQTT library ?
I can send small packet .. cca 30 bytes, but packet with 255 bytes doesnt to send.

Andrej

 

[inakigarm]

As B4R MQTT library is based on https://github.com/knolleary/pubsubclient , it seems that MQTT_MAX_PACKET_SIZE is hardcoded to 128 bytes in PubSubClient.h (in B4R Libraries/rMQTT Folder)

I suppose that changing to 255 will do the job (NOT Tested !!)

// MQTT_MAX_PACKET_SIZE : Maximum packet size
#ifndef MQTT_MAX_PACKET_SIZE
#define MQTT_MAX_PACKET_SIZE 255
#endif

 

[Andrej Meszaros]

Thank You.
I will test it.

 

[Andrej Meszaros]

In B4R there is no possibility to use this.
// MQTT_MAX_PACKET_SIZE : Maximum packet size
#ifndef MQTT_MAX_PACKET_SIZE#define MQTT_MAX_PACKET_SIZE 255#endif

 

[inakigarm]

In B4R there is no possibility to use this.
// MQTT_MAX_PACKET_SIZE : Maximum packet size
#ifndef MQTT_MAX_PACKET_SIZE#define MQTT_MAX_PACKET_SIZE 255#endif

Maybe I didn't explain correctly; this option is not in B4R IDE;you'll have to find PubSubClient.h file in B4R Libraries/rMQTT folder (search for it in your HD), and edit this field (actual value 128 and modify to 255 )

 

[Andrej Meszaros]

Thank You for detail explain. I found the file, edit to 255 but not working.
After change the buffer size to 300 I can send 256 byte packet.

 

[Erel]

After change the buffer size to 300

If you are using ESP8266 then you can set it to 1000 or more.