Payload passed to the publish method of MQTT did not send properly

[chuxuanhy]

I tried publishing a message, the message did not being sent correctly, the value of topic was always sent as payload message.

[nihaopaul]

Try sharing code snippets
On 24 Dec 2015 6:19 pm, "chuxuanhy" notifications@github.com wrote:

I tried publishing a message, the message did not being sent correctly,
the value of topic was always sent as payload message

—
Reply to this email directly or view it on GitHub
#9.

[chuxuanhy]

I used the following code snippets and I always received "/tangtret/phongtrung/tran/tu/relay1" or "/tangtret/phongtrung/tran/tu/relay2" instead of "ON" / "OFF" value.

print("------mqtt demo------")

cfg={
ssid='xxxxxx',
pwd='xxxxxx'}
wifi.startsta(cfg);
cfg=nil;

tmr.start(1,1000,function()
print('Check STA Status:'..wifi.sta.getip())
if(wifi.sta.getip()~='0.0.0.0') then
tmr.stop(1)
doMQTT()
end
end)

clientid = "EMW3165_" .. mcu.chipid()
keepalive = 999999999
username = 'xxxxxx'
password = 'xxxxxx'
server = 'ntm.diyoracle.com'
port = 1883
subTopic = "/tangtret/phongtrung/tran/toi/#"
mainTopic = "/tangtret/phongtrung/tran"
QoS = mqtt.QOS0
mqttClt = mqtt.new(clientid,keepalive, username,password)
function doMQTT()
mqtt.on(mqttClt,'connect',
function()
print('mqtt connected to server')
mqtt.subscribe(mqttClt,subTopic,QoS)
print('mqtt subscribe topic:'..subTopic)
end)
mqtt.on(mqttClt,'offline',
function()
print('mqtt disconnected from server')
end)
mqtt.on(mqttClt,'message',cb_messagearrived)
mqtt.start(mqttClt,server,port)
end
...
gpio04 = 4
gpio.mode(gpio04,gpio.INPUT_PULL_UP)
tmr.start(3, 100, function()
if gpio.read(gpio04) == 0 then
-- print ("Button 0 = On")
if switch2 == 1 then
--print ("Switch already on")
else
switch2 = 1
print ("Switch2 on")
mqtt.publish(mqttClt, "/tangtret/phongtrung/tran/tu/relay2",mqtt.QOS0, 'OFF')
end
else
-- print ("Button 0 = Off")
if switch2 == 0 then
--print ("Switch already Off")
else
switch2 = 0
print ("Switch2 off")
mqtt.publish(mqttClt, "/tangtret/phongtrung/tran/tu/relay2",mqtt.QOS0, 'ON')
end
end
end)

[SmartArduino]

What do you get if you try:test.mosquitto.org for test?

[chuxuanhy]

It also behaved as mention before, the client sent the topic string as payload. Please look at the following picture!
http://i.imgur.com/0GTtjBU.jpg

Would you please fix this soon?

[nihaopaul]

you'll have to use callbacks:

1. setup connections/config
2. initiate connection, return callback
3. on callback subscribe to channel, return callback
4. on callback publish payload

if you receive a value, that is not a string, then you'll need to cast it to a number:
value = tonumber(value)

• sorry i dont have my wifimcu with me to test on

[chuxuanhy]

Oh my god, believe me, I played with MQTT protocol for several projects before, I am sure the MQTT library of this wifimcu has issue with publishing message. The demo also did not publish 'hiwifimcu', it published the topic instead. Please tell the one who developed the library about this problem. Please ... please, I am not good at C++ to understand the original source in C of this library.

[SmartArduino]

The demo is tested between two wifimcus, and it works. It's true that it published the topic if only one wifimcu was used. We found this while coding. This is the function provided from MXChip.inc SDK. Let us know if any more prolems.

[wuming123057]

Mqtt client publish message, message content is the topic name.like this:

message recevied from /a/a: qos=0 
/a/a
message recevied from /a/a: qos=0     
/a/a
message recevied from /a/a: qos=0    
/a/a
message recevied from /a/a: qos=0   
/a/a
message recevied from /a/a: qos=0   
/a/a

This is my code

topic='/a/a'
mqtt.publish(mqttClt,topic,mqtt.QOS0, 'hiwifimcu').

And I have test

topic='/a/a'
mqtt.publish(mqttClt,topic,mqtt.QOS0, 0,'hiwifimcu').

It is normal when I use other client's API.

[SmartArduino]

The mqtt publish bug is fixed.
The firmware is updated to 0.9.8.1
Thanks all. @chuxuanhy @nihaopaul @wuming123057