Subsribing to the topic is not working

[priya2212]

Hi everyone, I am trying to work with this library to provide MQTT to SIM800 module. I am using Arduino UNO board. I am successfully able to publish the message on the topic but when I am subscribing to the topic and in the callback function, I am controlling the LED based on the message received: Subscription function:

void GSM_MQTT::OnConnect(void) { subscribe(0, "qewhrquwkfh", "GPRSLED", 1);; }

Callback function:

void GSM_MQTT::OnMessage(char Topic, int TopicLength, char Message, int MessageLength) { mySerial.println(TopicLength); mySerial.println(Topic); mySerial.println(MessageLength); mySerial.println(Message);

if (message[0] == '1') { digitalWrite(2, HIGH); } }

it seems like the callback function is not getting executed. It would be great for me, if anyone can guide me to resolve this issue. Please help me! Thanks & Regards, Priya

[arminsalcin]

@priya2212 Hello you need to subscribe in void loop exactly in " if (MQTT.available()) " function and add line:

MQTT.subscribe(0, 122212, "GPRSLED", 1);

[elementzonline]

Issue due to incorrect usage of library. Please use the examples