Hi all,
I am a newbie to Arduino and just trying out the pre-formatted examples first 
I have the AZ3166 (MX chip) Board AKA the Azure IoT Starter Kit, which comes with a MQTT example.
Besides, I have installed Mosquitto on my Synology NAS (also hosting Domoticz), which is running fine: Domoticz is posting and Mosquitto is handling all the messages.
When I simply install the MQTT example on the AZ3166, it works fine (this sends out a loop of messages to mqtt.eclipse.org. Here is the example Sketch:
#include <AZ3166WiFi.h>
#include "MQTTClient.h"
#include "MQTTNetwork.h"
#include "Telemetry.h"
int status = WL_IDLE_STATUS;
int arrivedcount = 0;
bool hasWifi = false;
const char* mqttServer = "mqtt.eclipse.org";
int port = 1883;
void initWifi()
{
Screen.print("IoT DevKit\r\n \r\nConnecting...\r\n");
if (WiFi.begin() == WL_CONNECTED)
{
IPAddress ip = WiFi.localIP();
Screen.print(1, ip.get_address());
hasWifi = true;
Screen.print(2, "Running... \r\n");
}
else
{
Screen.print(1, "No Wi-Fi\r\n ");
}
}
void messageArrived(MQTT::MessageData& md)
{
MQTT::Message &message = md.message;
char msgInfo[60];
sprintf(msgInfo, "Message arrived: qos %d, retained %d, dup %d, packetid %d", message.qos, message.retained, message.dup, message.id);
Serial.println(msgInfo);
sprintf(msgInfo, "Payload: %s", (char*)message.payload);
Serial.println(msgInfo);
++arrivedcount;
}
int runMqttExample() {
char* topic = "mqtt-sample";
MQTTNetwork mqttNetwork;
MQTT::Client<MQTTNetwork, Countdown> client = MQTT::Client<MQTTNetwork, Countdown>(mqttNetwork);
arrivedcount = 0;
char msgBuf[100];
sprintf(msgBuf, "Connecting to MQTT server %s:%d", mqttServer, port);
Serial.println(msgBuf);
int rc = mqttNetwork.connect(mqttServer, port);
if (rc != 0) {
Serial.println("Connected to MQTT server failed");
} else {
Serial.println("Connected to MQTT server successfully");
}
MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
data.MQTTVersion = 3;
data.clientID.cstring = "mqtt-sample";
data.username.cstring = "testuser";
data.password.cstring = "testpassword";
if ((rc = client.connect(data)) != 0) {
Serial.println("MQTT client connect to server failed");
}
if ((rc = client.subscribe(topic, MQTT::QOS2, messageArrived)) != 0) {
Serial.println("MQTT client subscribe from server failed");
}
MQTT::Message message;
// QoS 0
char buf[100];
sprintf(buf, "QoS 0 message from AZ3166!");
message.qos = MQTT::QOS0;
message.retained = false;
message.dup = false;
message.payload = (void*)buf;
message.payloadlen = strlen(buf)+1;
rc = client.publish(topic, message);
while (arrivedcount < 1) {
client.yield(100);
}
// QoS 1
sprintf(buf, "QoS 1 message from AZ3166!");
message.qos = MQTT::QOS1;
message.payloadlen = strlen(buf)+1;
rc = client.publish(topic, message);
while (arrivedcount < 2) {
client.yield(100);
}
if ((rc = client.unsubscribe(topic)) != 0) {
Serial.println("MQTT client unsubscribe from server failed");
}
if ((rc = client.disconnect()) != 0) {
Serial.println("MQTT client disconnect from server failed");
}
mqttNetwork.disconnect();
Serial.print("Finish message count: ");
Serial.println(arrivedcount);
return 0;
}
void setup() {
//Initialize serial and Wi-Fi:
Serial.begin(115200);
initWifi();
if(hasWifi)
{
// Microsoft collects data to operate effectively and provide you the best experiences with our products.
// We collect data about the features you use, how often you use them, and how you use them.
send_telemetry_data_async("", "MQTTClientSetup", "");
}
}
void loop() {
Serial.println("\r\n>>>Enter Loop");
if (hasWifi) {
runMqttExample();
}
delay(5000);
}
Now, when I only replace the address of the MQTT server with the Mosquitto one, I cannot connect to Mosquitto (Wifi connection is OK however, AZ3166 has an IP address assigned, which I can reach with ping from my computer):
const char* mqttServer = "192.168.178.250" //Mosquitto on NAS;
However, I am able to reach Mosquitto from my computer (using MQTT Explorer and MQTT.fx - both connect and are able to post test messages to Mosquitto). Besides, I added a line of code to the Sketch to show the return code (rc). This showed "-3004" which is a rather strange code - not a default Mosquitto response.
So it seems that:
- The Sketch code is OK (AZ3166 is able to post messages)
- Mosquitto is OK (can be reached from external client)
But for some reason, my AZ3166 is not able to reach Mosquitto.
What am I doing wrong and what could I do to test/check things? (I tried Wireshark, but then realised that this only shows traffic to/from my computer and will not show the AZ3166 traffic to Mosquitto?).
Any help is appreciated!
