Mqtt con Beaglebone ed ESP8266-MQTT su ESP8266 per sensore temperatura

Dopo aver caricato il firmware sul dispositivo esp8266

Mqtt con Beaglebone ed ESP8266-MQTT ESP8266

si passa a collegare tale modulo con un sensore di temperatura ed umidità DHT11. Di seguito i collegamenti utilizzati

Nell’esempio che faremo si considererà l’opzione di mettere il nodemcu in sleep. Perché il sistema possa riavviarsi dopo il comando di sleep è necessario collegare il PIN D0 (GPIO16) al PIN RST come specificato nella documentazione nodemcu

Nodemcu sleep

Passiamo ad analizzare il codice da caricare sul dispositivo; consta del file init.lua e del file tempumid.lua.

Analizziamo i punti principali di ciascun file.

init.lua

-- init.lua
SSID="SSDNAME" -- SSID 
PASSWORD="passwordssid" -- SSID password
TIMEOUT=10000    -- timeout to check the network status
EXSENSOR1="tempumid.lua"    -- module to run
MQTTSERVER="mqttbrokeraddress"   -- mqtt broker address
MQTTPORT="1883"  -- mqtt borker port
MQTTQOS="0" -- qos used

-- Set the netowrk parameters and get ip address
wifi.setmode(wifi.STATION)
wifi.sta.config(SSID, PASSWORD)
wifi.sta.getip()

-- Check the network status after the TIMEOUT interval
tmr.alarm(0, TIMEOUT,tmr.ALARM_SINGLE, function()
    status=wifi.sta.status()
    
    -- if esp8266 got the ip
   if (status == wifi.STA_GOTIP ) then

       dofile(EXSENSOR1)
        
    
    else
        -- Without ip restart the node
        print("Error acquiring ip address=",status)
        node.restart()
    end


end

-- init.lua

SSID="SSDNAME" -- SSID

PASSWORD="passwordssid" -- SSID password

TIMEOUT=10000 -- timeout to check the network status

EXSENSOR1="tempumid.lua" -- module to run

MQTTSERVER="mqttbrokeraddress" -- mqtt broker address

MQTTPORT="1883" -- mqtt borker port

MQTTQOS="0" -- qos used

-- Set the netowrk parameters and get ip address

wifi.setmode(wifi.STATION)

wifi.sta.config(SSID, PASSWORD)

wifi.sta.getip()

-- Check the network status after the TIMEOUT interval

tmr.alarm(0, TIMEOUT,tmr.ALARM_SINGLE, function()

status=wifi.sta.status()

-- if esp8266 got the ip

if (status == wifi.STA_GOTIP ) then

dofile(EXSENSOR1)

else

-- Without ip restart the node

print("Error acquiring ip address=",status)

node.restart()

end

Nel file sono impostate globalmente i parametri dell’access point, l’indirizzo e porta del broker mqtt ed il file da eseguire sull’esp dopo la connessione all’access point. Nel caso non riesca ad acquisire l’indirizzo il sistema viene fatto ripartire.

tempumid.lua

-- tempumid.lua
CNAME="room1" -- Client name 
AMBIENT="home"  -- Ambient name
TTOPIC     = AMBIENT.."/"..CNAME.."/temperature"  -- Temperature topic
HTOPIC     = AMBIENT.."/"..CNAME.."/humidity"  -- Humidity topic 
STOPIC     = AMBIENT.."/"..CNAME.."/status"  -- Status topic
CTOPIC     = AMBIENT.."/"..CNAME.."/command" --Command topic   
MTOPIC     = AMBIENT.."/"..CNAME.."/monitor" --Monitor topic


sleep_in_seconds= nil --Sleep in seconds


TUPDATE = 15 -- Time interval for update monitor in seconds
TUPTEMP = 10 -- Time interval for update temperature and humidity values
SPIN         = 4  -- Sensor pin
TGEN = 5 -- Time interval in seconds usend in various trm


-- Define Client Name and connection parameters
mqt = mqtt.Client(CNAME, 60, "", "", 1) 

-- Subscribe to the topics and send status to the status topic
mqt:on("connect", function() 
    mqt:subscribe(STOPIC, MQTTQOS)
    mqt:subscribe(CTOPIC, MQTTQOS)
    mqt:subscribe(MTOPIC, MQTTQOS)
    mqt:subscribe(TTOPIC, MQTTQOS)
    mqt:subscribe(HTOPIC, MQTTQOS)
    send_status("Sensor ready again")
end )

-- Callback when mqtt is offline
mqt:on("offline", function() print("mqtt offline");  end)

--Callback to manage messages 
mqt:on("message", function(client, topic, data) 
    manage_message(client, topic, data) 
end)


-- Function to filter the messages
function manage_message(client, topic, data) 
    -- If CTOPIC: command topic
    if topic == CTOPIC then
        --print("Command")
        -- If the command is Restart
        if data == "Restart" then
            send_status("Restarting")
            send_mstatus("Restarting")
            tmr.alarm(2, TGEN*1000, tmr.ALARM_SINGLE, node.restart)
            --print("restart")
        -- If the command is null    
        elseif data == nil then
           -- print("Command not valid")
            send_status("Command not valid")
        
        
        else
            -- Check the Sleep command           
            i=string.len(data)
            dato=string.sub(data,1,5)
          
            if dato == "Sleep" then
                ndato=string.sub(data,6)
                TSLEEP=tonumber(ndato)
                if TSLEEP ~= nil then
                    if TSLEEP >= 1 then
                        -- Sets the interval in seconds to sleep
                        sleep_in_seconds=TSLEEP*60
                        esp_sleep()
                    else
                        -- Send an error in Sleep command
                        send_status("Sleep command error")
                    
                    end
                else
                    -- Send an error in Sleep command 
                    send_status("Sleep command error")
                end

            else
                -- Command not managed           
                send_status("Command not valid")      

            end
            
        end
        
    end
end

-- Function to send messages to STOPIC: status topic
function send_status(message)
    mqt:publish(STOPIC, message, MQTTQOS, 0)
    
end

-- Fucntion to send messages to MTOPIC: monitor topic
function send_mstatus(message)
    mqt:publish(MTOPIC, message, MQTTQOS, 0)
    
end

-- Function to display temp and hum
function display_temphum(temp,humi)
    print("Temperature=%d, Humidity=%d",temp,humi)
end

 
-- Function to read and publish temperature and humidity
function read_temp_hum(client)
    status, temp, humi, temp_dec, humi_dec = dht.read(SPIN)
    if status == dht.OK then
    
        mqt:publish(TTOPIC, temp,MQTTQOS, 0)
        mqt:publish(HTOPIC, humi, MQTTQOS, 0)
        
       -- display_temphum(temp,humi)
       
    elseif status == dht.ERROR_CHECKSUM then
        print( "DHT Checksum error." )
    elseif status == dht.ERROR_TIMEOUT then
        print( "DHT timed out." )
    end
end


-- Function that sleeps esp8266
function esp_sleep()
 
    send_status("Sensor going to sleep now")
    send_mstatus("Sensor going to sleep now")
    -- Delayd sleep to send the message above.
    tmr.alarm(3, TGEN*1000, tmr.ALARM_SINGLE, function() 
        node.dsleep(sleep_in_seconds*1000000) 
    end)
end

-- Connection to the mqtt server at the mqttport
mqt:connect(MQTTSERVER, MQTTPORT, 0, 1)

--Sends periodically the temperature and humidity to the topics
tmr.alarm(1, TUPTEMP*1000, tmr.ALARM_AUTO, function() read_temp_hum(mqt) end)

-- Sends periodically a message to the monitor topic
tmr.alarm(4, TUPDATE*1000, tmr.ALARM_AUTO, function() send_mstatus("Sensor Ready") end)

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-- tempumid.lua

CNAME="room1" -- Client name

AMBIENT="home" -- Ambient name

TTOPIC = AMBIENT.."/"..CNAME.."/temperature" -- Temperature topic

HTOPIC = AMBIENT.."/"..CNAME.."/humidity" -- Humidity topic

STOPIC = AMBIENT.."/"..CNAME.."/status" -- Status topic

CTOPIC = AMBIENT.."/"..CNAME.."/command" --Command topic

MTOPIC = AMBIENT.."/"..CNAME.."/monitor" --Monitor topic

sleep_in_seconds= nil --Sleep in seconds

TUPDATE = 15 -- Time interval for update monitor in seconds

TUPTEMP = 10 -- Time interval for update temperature and humidity values

SPIN = 4 -- Sensor pin

TGEN = 5 -- Time interval in seconds usend in various trm

-- Define Client Name and connection parameters

mqt = mqtt.Client(CNAME, 60, "", "", 1)

-- Subscribe to the topics and send status to the status topic

mqt:on("connect", function()

mqt:subscribe(STOPIC, MQTTQOS)

mqt:subscribe(CTOPIC, MQTTQOS)

mqt:subscribe(MTOPIC, MQTTQOS)

mqt:subscribe(TTOPIC, MQTTQOS)

mqt:subscribe(HTOPIC, MQTTQOS)

send_status("Sensor ready again")

end )

-- Callback when mqtt is offline

mqt:on("offline", function() print("mqtt offline"); end)

--Callback to manage messages

mqt:on("message", function(client, topic, data)

manage_message(client, topic, data)

end)

-- Function to filter the messages

function manage_message(client, topic, data)

-- If CTOPIC: command topic

if topic == CTOPIC then

--print("Command")

-- If the command is Restart

if data == "Restart" then

send_status("Restarting")

send_mstatus("Restarting")

tmr.alarm(2, TGEN*1000, tmr.ALARM_SINGLE, node.restart)

--print("restart")

-- If the command is null

elseif data == nil then

-- print("Command not valid")

send_status("Command not valid")

else

-- Check the Sleep command

i=string.len(data)

dato=string.sub(data,1,5)

if dato == "Sleep" then

ndato=string.sub(data,6)

TSLEEP=tonumber(ndato)

if TSLEEP ~= nil then

if TSLEEP >= 1 then

-- Sets the interval in seconds to sleep

sleep_in_seconds=TSLEEP*60

esp_sleep()

else

-- Send an error in Sleep command

send_status("Sleep command error")

end

else

-- Send an error in Sleep command

send_status("Sleep command error")

end

else

-- Command not managed

send_status("Command not valid")

end

-- Function to send messages to STOPIC: status topic

function send_status(message)

mqt:publish(STOPIC, message, MQTTQOS, 0)

end

-- Fucntion to send messages to MTOPIC: monitor topic

function send_mstatus(message)

mqt:publish(MTOPIC, message, MQTTQOS, 0)

end

-- Function to display temp and hum

function display_temphum(temp,humi)

print("Temperature=%d, Humidity=%d",temp,humi)

end

-- Function to read and publish temperature and humidity

function read_temp_hum(client)

status, temp, humi, temp_dec, humi_dec = dht.read(SPIN)

if status == dht.OK then

mqt:publish(TTOPIC, temp,MQTTQOS, 0)

mqt:publish(HTOPIC, humi, MQTTQOS, 0)

-- display_temphum(temp,humi)

elseif status == dht.ERROR_CHECKSUM then

print( "DHT Checksum error." )

elseif status == dht.ERROR_TIMEOUT then

print( "DHT timed out." )

end

-- Function that sleeps esp8266

function esp_sleep()

send_status("Sensor going to sleep now")

send_mstatus("Sensor going to sleep now")

-- Delayd sleep to send the message above.

tmr.alarm(3, TGEN*1000, tmr.ALARM_SINGLE, function()

node.dsleep(sleep_in_seconds*1000000)

end)

end

-- Connection to the mqtt server at the mqttport

mqt:connect(MQTTSERVER, MQTTPORT, 0, 1)

--Sends periodically the temperature and humidity to the topics

tmr.alarm(1, TUPTEMP*1000, tmr.ALARM_AUTO, function() read_temp_hum(mqt) end)

-- Sends periodically a message to the monitor topic

tmr.alarm(4, TUPDATE*1000, tmr.ALARM_AUTO, function() send_mstatus("Sensor Ready") end)

Il file temumid.lua gestisce la misura della temperatura ed umidità, la sottoscrizione sul broker mqtt con invio dei dati rilevati. Sono stati impostati dei parametri globali per gestire i topic, i tempi di attesa in tmr.alarm. Sono presenti in particolare i seguenti topic

/home/room1/temperature: vengono inviati i dati della temperatura rilevata.
/home/room1/humidity: vengono inviati i dati della umidità rilevata.
/home/room1/status : viene inviato lo stato del sensore all’avvio ed in risposta dei comandi nel topic /home/room1/command.
/home/room1/monitor: periodicamente viene inviato lo stato del sensore.
/home/room1/command: Da altri client è possibile inviare dei comandi al sensore.
- Restart: riavvia il sensore.
- Sleep n: Tempo di sleep di n secondi.

Vi sono varie funzioni di servizio che gestiscono il tutto. I commenti all’interno del codice descrivono ciascuna funzionalità.

Nel prossimo articolo imposteremo l’esp con il relé

Mqtt con Beaglebone ed ESP8266-MQTT su ESP8266 per Relé

Micro Devices

Mqtt con Beaglebone ed ESP8266-MQTT su ESP8266 per sensore temperatura

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