MQTT with BeagleBone and ESP8266 – MQTT on ESP8266 with temperature sensor

2017-03-23 admin

After loading the firmware into the device esp8266

MQTT with BeagleBone and ESP8266-MQTT ESP8266

we now connect this module with a DHT11 temperature and humidity sensor. Here is how we connect the sensor to the ESP module

In this example we will consider the option of putting the nodemcu in sleep. To have the node back form the sleep the system has to reboot and it is necessary to connect the PIN D0 (GPIO16) to RST PIN as specified in the nodemcu documentation

Nodemcu sleep

Let us take a look at the lua code; It consists of init.lua and tempumid.lua files.

We analyze now the main points of each 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

In the file we set the the parameters to access the wifi network, the address and port of the MQTT broker and the file to be run on the ESP after wifi connection to the access point is estabilished. If the ESP does’t acquire the netowrk address the system is restarted.

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)

The temumid.lua file manages the measurement of temperature and humidity, the subscription on MQTT broker with submission of the data. Global parameters have been set to manage the topic, the waiting time in tmr.alarm. There are in particular the following topics

/home/room1/temperature: measured temperature topic.
/home/room1/humidity: measured humidity topic.
/home/room1/status : Status topic. The status is sent at the start and at request from the command topic /home/room1/command.
/home/room1/monitor: Status of the esp sent periodically to this topic.
/home/room1/command: Other clients can send commands to the esp:
- Restart: Restarts the esp.
- Sleep n: Put to sleep for n seconds the esp.

There are various service functions to manage all. The comments in the code describe each feature.

In the next article we will set up the esp with the relay

MQTT with BeagleBone and ESP8266 – MQTT on ESP8266 with Relay

Configuration, Software

Mqtt with Beaglebone and ESP8266-MQTT ESP8266

2017-03-19 admin

After installing the MQTT server on BeagleBone

Mqtt with Beaglebone and ESP8266-Mosquitto installation on Beaglebone

let us set the MQTT nodes on ESP8266.

As first operation we must generate the nodemcu firmware, as described in the previous article

Nodemcu compilation on Linux

with at least the following parameters activated in user_module.h file

DHT
file
GPIO
MQTT
net
node
timer
UART
WiFi

These settings are the default in the user_module.h file.

At present the latest version 2.0 of nomemcu firmware was released. Here are the compiled files for this version of the firmware

Nodemcu2.0.0 firmware

As already described in previous articles and from the nodecmu link on flashing

Flashing the firmware

we have to set the correct parameters for the esp8266 model.

In our case, with 4MB flash, we used the parameters shown in the image to load the firmware on the device with nodemcu-flasher tool. You can also use other tools for loading the firmware. In our case, the settings used are as follows

In the next article we’ll treat the ESP8266 node that detects temperature and humidity

MQTT with BeagleBone and ESP8266 – MQTT on ESP8266 with temperature sensor

Configuration, Software

MQTT with BeagleBone and ESP8266 – Mosquitto installation on Beaglebone

2017-03-12 admin

After summarizing the architecture that we are implementing in the previous article

Mqtt with Beaglebone and ESP8266-Architecture

We proceed now with the installation of the MQTT broker on Beaglebone Black with the following version of Debian

root@beaglebone:~#  cat /etc/dogtag
BeagleBoard.org Debian Image 2016-11-06
root@beaglebone:~# uname -a
Linux beaglebone 4.4.30-ti-r64 #1 SMP Fri Nov 4 21:23:33 UTC 2016 armv7l GNU/Lux

root@beaglebone:~# cat /etc/dogtag

BeagleBoard.org Debian Image 2016-11-06

root@beaglebone:~# uname -a

Linux beaglebone 4.4.30-ti-r64 #1 SMP Fri Nov 4 21:23:33 UTC 2016 armv7l GNU/Lux

The image used is the following

Beaglebone Black Image

We proceed to the configuration as described in the article

Debian sd card setup for Beaglebone Black

Proceed to extend the space on the SD card with the application gparted in a linux host or using the grow_partition.sh tool on BeagleBone in the /opt/scripts/tools folder

root@beaglebone:/opt/scripts/tools# ./grow_partition.sh

1	root@beaglebone:/opt/scripts/tools# ./grow_partition.sh

Performing the upgrade with this image we have had space issue with 4Gb partition.

The message broker we’ll use is mosquitto

Mosquitto

The version of Mosquitto with Debian Jessie doesn’t not have the Wesockets services, which we’ll use for the Dashboard. For this reason, we have to install a more recent version of Mosquitto (or recompile it from source).

Log on as root in a command shell on BeagleBone and add the Debian testing repository

cd /etc/apt
vi sources.list

1 2	cd /etc/apt vi sources.list

deb http://httpredir.debian.org/debian stretch main contrib non-free

1	deb http://httpredir.debian.org/debian stretch main contrib non-free

Run the following

apt-get update
apt-get install mosquitto
apt-get install mosquitto-clients

apt-get update

apt-get install mosquitto

apt-get install mosquitto-clients

After the installation comment the reference of the debian testing repository in /etc/apt/sources.list

#deb http://httpredir.debian.org/debian stretch main contrib non-free

1	#deb http://httpredir.debian.org/debian stretch main contrib non-free

and run

apt-get update

1	apt-get update

We test at this point if the server is installed correctly by running in a shell the subscription to a topic

mosquitto_sub -h localhost -t "topic/test"

1	mosquitto_sub -h localhost -t "topic/test"

In another command shell run the publishing on topic “topic / test”

mosquitto_pub -h localhost -t "topic/test" -m "Prova"

1	mosquitto_pub -h localhost -t "topic/test" -m "Prova"

The first shell has to show the message “Prova”

With MQTT protocol we can define different QOS, as described in the Mosquitto FAQ

QOS Mosquitto

With QoS = 0 the message is sent only once and is not required confirmation of receipt by the subscribers; the MQTT implementation in these articles is without protection with name/password or ssl channel encryption and with QOS=0.

In the next article we’ll proceed to the preparation of ESP9266 module with the Mqtt lua library inside the nodemcu firmware

MQTT with BeagleBone and ESP8266-MQTT ESP8266

Configuration, Software

Mqtt with Beaglebone and Esp8266-Architecture

2017-03-12 admin

In this series of articles we treat a MQTT message broker installed on BeagleBone Black; this componet allows to manage various esp8266 devices, to which we connect various probes such as temperaure sensors, relays.

All this is handled with the help of apps on Android and a Dashboard installed on Apache on BeagleBone.

We start from the message MQTT broker (Message Queue Telemetry Transport); here there is the description of the protocol

MQTT

In particular in the FAQ section there are the first indications on the protocol and its use

MQTT Faq

The system is formed by three components:

MQTT Broker: relays the messages published to all subscribers.
Publisher: Publish messages in the registered topics on MQTT Broker.
Subscriber: Receives messages for its registered topics from MQTT Broker.

The following shows the topology for two topics used in our example

The system is composed of a MQTT broker on BeagleBone. In this MQTT broker server you can define topics; different devices can be registered to these topics. For each topic the action can be subscription and publishing. By subscribing you receive all messages of topics, while with the publishing we can perform actions on the topic (for example, turn on a relay, restart a device, send sensor measurement,etc.). In the example we treat there will be, for example, a queue for the temperature monitor, hooked to esp8266 temperature reading device, another for the management of a relay, always run with esp8266. The MQTT broker relays the received messages among all subscribers/ publishers for each topic.

We can subcribe/publish to the topics on the MQTT broker using Android apps; the apps can receive messages and send commands to the esp8266 end device (Turn onRelay, Restart sensor, etc.).

With the javascript framework Freeboard

Freeboard

installed on the Beablebone Apache web server we can monitor in real time the end devices.

For more informations on MQTT system, consult the web site listed above.

In the next article we’ll start by installing the MQTT broker on BeagleBone Black

MQTT with BeagleBone and ESP8266 – Mosquitto installation on Beaglebone

Micro Devices

Monthly Archives: March 2017

MQTT with BeagleBone and ESP8266 – MQTT on ESP8266 with temperature sensor

Mqtt with Beaglebone and ESP8266-MQTT ESP8266

MQTT with BeagleBone and ESP8266 – Mosquitto installation on Beaglebone

Mqtt with Beaglebone and Esp8266-Architecture

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