Receiving empty messages with secured MQTT subscription
Posted: Sun Feb 14, 2016 8:19 am
I'm trying to securely connect ESP8266 to MQTT Azure Protocol Gateway broker on cloud or local computer (tried both) like this:
ESP connects to server and handshake is completed successfully. When I publish some data, I can read it on server properly, it is OK. I subscribe to topic without problems. When I send data in cloud-to-device message from server to ESP to subscribed topic, 'on message' event is called but data attribute passed to the function is EMPTY string.
I'm using latest NodeMCU master build based on 1.4.0 SDK and also tried dev version.
I tried following:
EDIT:
Here is debug output, nothing interesting there...
Code: Select all
m = mqtt.Client("{deviceId}", "3600", "{iotHub}/{deviceId}", "{SASToken}")
...
m:on("message", function(conn, top, data)
print(data) -- EMPTY string here!
end)
...
m:connect({IP}, 8883, 1, function(conn)
m:subscribe("devices/{deviceId}/messages/devicebound/#", 1, function(conn)
...
end)
end)
ESP connects to server and handshake is completed successfully. When I publish some data, I can read it on server properly, it is OK. I subscribe to topic without problems. When I send data in cloud-to-device message from server to ESP to subscribed topic, 'on message' event is called but data attribute passed to the function is EMPTY string.
I'm using latest NodeMCU master build based on 1.4.0 SDK and also tried dev version.
I tried following:
- free memory up to 32kB - not help
- captured packets with WireShark: packets contain encrypted data with some lenght, so it is not empty and packet size is less than 2kB buffer size
EDIT:
Here is debug output, nothing interesting there...
Code: Select all
enter mqtt_socket_received.
MQTT_DATA: type: 3, qos: 0, msg_id: 0, pending_id: 0
enter deliver_publish.
string
userdata: 3fff3e88
devices/ESP/messages/devicebound
<- here should be printed data
On
leave deliver_publish.
receive, queue size: 0
leave mqtt_socket_received.
enter mqtt_socket_timer.
timer, queue size: 0
keep_alive_tick: 71
leave mqtt_socket_timer.
enter mqtt_socket_received.
MQTT_DATA: type: 7, qos: 1, msg_id: 8813, pending_id: 0
receive, queue size: 0
leave mqtt_socket_received.