- Sun Jan 18, 2015 10:46 pm
#7657
This is great stuff - I am an absolute beginner with both LUA and MQTT, using an ESP-01 I came up with a pretty simple example that uses the ESP-01 as both an input device (button) and an output device (LED). You can have it send a MQTT message on button press as well as receive commands to control the LED. I thought the example might help other beginners. If there are better ways to do this please reply.
(I do see issues with this code when ran for init.lua, it looks the subscribe command runs before the connection is fully setup so it doesn't actually subscribe. I tried adding some delays in both the connect callback function and before the subscribe but it doesn't seem to address it. Any ideas appreciated. (Copying the code manually or through ESPlorer works correctly (just make sure you get both a 'Connected" and a "Subscribe success" response))
(I do see issues with this code when ran for init.lua, it looks the subscribe command runs before the connection is fully setup so it doesn't actually subscribe. I tried adding some delays in both the connect callback function and before the subscribe but it doesn't seem to address it. Any ideas appreciated. (Copying the code manually or through ESPlorer works correctly (just make sure you get both a 'Connected" and a "Subscribe success" response))
Code: Select all
--Setup using ESP-01 and the NodeMCU version with MQTT Support
--GPIO2 - connected to 300 Ohm restistor -> LED -> Ground
--GPIO0 - Connected to Normally open button with other button leg connected to ground
-- Setup Mqtt-Spy with a subscription to /topicOut and to send to /topicIn
-- Chnage the IP and Port to your broker (I use mosquitto)
-- If you push the button you should see Pin0Down in mqttspy
-- If you send ON in mqttspy the LED should light, send off it should go OFF
--SetupMQTT
mqtt = net.createConnection(net.TCP, 0)
mqtt:mqtt("ESP8266-2", 30, "user", "password")
-- on connection event (all event inherit from net module)
mqtt:on("connection", function(con) print("connected") end)
mqtt:connect(8443,"192.168.0.32")
--Setup MQTT Sending
--Pin 3 is GPIO 0 on the ESP-01 - Connected to Normally open button connected to ground
gpio.mode(3,gpio.INPUT,gpio.PULLUP)
gpio.trig(3, "down",function (level)
mqtt:send("/topicOut","Pin0Down",0,0)
print("Sent MQTT Message to /topicOut")
end)
--Setup MQTT Recieve
--Pin 4 is GPIO2 on the ESP-01 - connected to 300 Ohm restistor -LED -Ground
gpio.mode(4,gpio.OUTPUT)
gpio.write(4,gpio.LOW)
-- on publish message receive event
mqtt:on("receive", function(conn, topic, data)
print("Recieved:" .. topic .. ":" .. data)
if (data=="ON") then
print("Enabling LED")
gpio.write(4,gpio.HIGH)
elseif (data=="OFF") then
print("Disabling LED")
gpio.write(4,gpio.LOW)
else
print("Invalid - Ignoring")
end
end)
mqtt:subscribe("/topicIn",0, function(conn) print("subscribe success:TopicIn") end)
