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Dear Team,
I have populated my data on ThingsBoard platform using ESP8266, now I want to read that data using MATLAB Industrial Communication Toolbox. I have written a code for this purpose below,
% Replace these values with your ThingsBoard MQTT broker details
brokerAddress = "ssl://demo.thingsboard.io"; % Adjust the broker address
port = 1883; % Use the appropriate port for secure MQTT
% Replace these values with your ThingsBoard device details
clientID = "";
userName = "";
password = ""; % Leave empty if not required
% Replace this with the path to the root certificate you downloaded
rootCert = "";
% Create an MQTT client
mqClient = mqttclient(brokerAddress, 'Port', port, 'ClientID', clientID, ...
'Username', userName, 'Password', password, 'CARootCertificate', rootCert);
% Check if the connection is established
mqClient.Connected
% Expected output: ans = int32(1)
% Subscribe to the telemetry topic
topicToSub = "v1/devices/me/telemetry";
subscribe(mqClient, topicToSub);
% Wait for a while to receive messages (adjust the time as needed)
pause(60);
% Peek at the MQTT client to view received messages
peek(mqClient);
% Close the MQTT client
clear mqClient;
%%%%__________________Output Result______________________%%%%%
>> MQTT_Receive
Warning: Using a port that allows unencrypted communication. For confidential matters, considering using an encryption
enforcing port, such as 8883.
Error using MQTT_Receive
Failed to establish a connection with broker "ssl://demo.thingsboard.io".
I desperately seeking your assistance in this regard
Alan Benn
Alan Benn
Última actividad el 4 de Dic. de 2023

I'm logging data which I'd like to see on a daily basis. ie each day the chart x axis resets to 12midnight to 12midnight for the current day and just shows todays data. Is this possible please ?
William Glass
William Glass
Última actividad el 22 de Nov. de 2023

Hello
I have been using ThingSpeak for about 2 years with no problems. I am observing sensor data and connecting widgets to some of the values. Since yesterday, there are some of the widgets that send blank values. Have you changed something?
Thank you
Elija
Elija
Última actividad el 14 de Feb. de 2024

Hello, all!
This is my first post after just joining this discussion, so please forgive me and provide kind assistance if I have posted to the wrong subsection!
I have a good interest in learning sql server course and right now I am taking help from various platforms like https://www.coursera.org/ https://www.udemy.com/
Also I have a doubt that is it a good option to learn from platforms like this or I should go for some sql server online training . I have searched for the solution of my queries in various above platforms which helped me up to some extent only as it was not directly given by any expert or trainer.
Hoping in getting a quick response
Thankyou in advance.
Adrian Segura
Adrian Segura
Última actividad el 28 de Nov. de 2023

Hello, I am a student and I am working on a neural network for a line follower car and I would like you to recommend a tutorial to implement it in simulink.
Amatorskie Stacje
Amatorskie Stacje
Última actividad el 19 de Mzo. de 2024

Hello, I would like to send temperature and humidity data from my ThingSpeak channel to the https://www.wunderground.com/ service. I managed to configure the initial connection through ThingHTTP, and on the WeatherUnderground website, there is information about data updates, but there are no actual values: https://www.wunderground.com/dashboard/pws/IKORON5/table/2023-11-19/2023-11-19/daily
I don't know how to correctly configure all the options in ThingHTTP and in the Apps - React section.
Daniel Bending
Daniel Bending
Última actividad el 15 de Nov. de 2023

The title is resonably non-descript, but I can explain it easily:
Say I have an initial Emax model:
v = emax1*[G]^n1/(ec501^n1+[G]^n1)
And I want to place v inside of a second Emax model:
y = emax2*v^n2/(ex502^n2+v^n2)
Currently, I have the full function of v inside y, twice, it's very long and whilst I only need to get it correct once, for readability in the future I'd rather have it in form #2. I've played around with non-constant parameters but I need the steady state to be v, not the rate rule, and I haven't worked out how to make a parameter shift to a form like v, as an observation might.
Are there any recommended solutions or do I simply need to keep with having v fully expressed in y?
Thank you,
Dan
when I examine the data stream on an arduino ide I get a lot of "stuff" which I dont understand.
1 what does it mean?
2 how do I prevent it?
Hello,
i want to write the power data from my Tasmota IR Device to my channels, but it does not work.
I have created 3 channels and i use the correct write API in the script. I use the following script:
>D
>B
=>sensor53 r
>S
if upsecs%20==0
then
=>WebSend [api.thingspeak.com] /update.json? api_key=xxxxxxxxxxxxxxxx&field1=%sml[1]%&field2=%sml[2]%&field3=%sml[3]%
endif
>M 1
+1,3,s,0,9600,
1,77070100010800ff@1000,Total consumption,kWh,total_in,2
1,77070100020800ff@1000,Total feed-in,kWh,total_out,2
1,77070100100700ff@1,Power,W,power_curr,0
#
I get the messages in the console that the data was send but my channels stay empty.
What do i miss ?
Thanks for help
LAWAN HARUNA
LAWAN HARUNA
Última actividad el 6 de Nov. de 2023

good afternoon everyone my name is Dundu lawan haruna ,i'm a final year student at the department of computer engineering ABU Zaria, Nigerian , and i wanted to do my final year project based on computer vision : project topic , designing an eye glasses to help those people with visual imparement to be able to navigate enviroment efficiently , that's why i need a support from you guys ,all advised are highly well come , thank you for your support.
Edward
Edward
Última actividad el 7 de Nov. de 2023

I am collecting Data at 1 minute intervals using esp8266, the data is then sent to Thingspeak on the minute intervals. However I would like to store the data collection on the esp Ram. I am using batteries to power the circuits , if I can store the data and send it on demand I can save quite a bit of battery energy (used up by wifi) - (I already use sleep mode between intervals). As well as using Thingspeak to visuliase the data, I also use a third part app called Thingview which 'feeds' off thingspeak. I am looking for a way to trigger the 'data send' upon opening thinkspeak chanel,so rather than sending every minute it might need to be accessed two or three times a day, is this possible?
Thanks Edward
Luca
Luca
Última actividad el 5 de Nov. de 2023

Hi!
I can't see my data in the charts. I'm using arduino wifi and the connection works.
Maybe I did something wrong in this options

Is there a way to get a handle or link to the database each time I do a WRITE or group of WRITEs? I need to access the set of records that comprises a user session, which could be many WRITEs. My impression is that Thingspeak appears as a continuous stream with no way to mark a set of WRITEs as a group or session. Methods I have tried like retrieval (READs) using timestamps and other after-the-fact queries are not very accurate or user friendly. Thanks.

Daniel Bending
Daniel Bending
Última actividad el 31 de Oct. de 2023

Hi All,
I'm currently attempting to implement a Hodgkin-Huxley-type model of membrane potential, ideally I would like a species that represents the membrane potential as its own distinct entity, so as the reference elsewhere. I've currently established a molarity-based work around but it would be great if I could set the units for the species as millivolt, but that throws an error.
Is there an established way to do this? I imagine I'm not the first person to be trying to model a voltage-gated ion channel!
Thank you for your help.
Image Analyst
Image Analyst
Última actividad el 31 de Oct. de 2023

Just in time for Halloween.
Share your fun photos in the comments!
Here's a MATLAB class I wrote that leverages the MATLAB Central Interface for MATLAB toolbox, which in turn uses the publicy available Community API. Using this class, I've created a few Favorites that show me what's going on in MATLAB Central - without having to leave MATLAB 🙂
The class has a few convenient queries:
  • Results for the last 7 days
  • Results for the last 30 days
  • Results for the current month
  • Results for today
And supporting a bunch of different content scopes:
  • All MATLAB Central
  • MATLAB Answers
  • Blogs
  • Cody
  • Contests
  • File Exchange
  • Exclude Answers content
The results are displayed in the command window (which worked best for me) and link to each post. Here's what that looks like for this command
>> CommunityFeed.thisMonth("app designer", CommunityFeed.Scope.ExcludeAnswers)
Let me know if you find this class useful and feel free to suggest changes.
Daniel Bending
Daniel Bending
Última actividad el 31 de Oct. de 2023

Hello,
I've looked around and I haven't found anything obvious about this, but is it possible to link to species/reactions, graphically, in a non-mass transfer sense? I have areas in my model where it would conceptually make sense to be able to see that species or reactions are linked, but if I link them in the standard way it demands that it be involved in the stoichiometry.
Perhaps some kind of dotted line, or similar?
Thank you, best regards,
Dan
Sakshi
Sakshi
Última actividad el 6 de Nov. de 2023

we are planning to design a drive for an EV using synchronous reluctance motor. To move further we need some drive circuits for simulating and comparing various motors with synchronous reluctance to justify our literature survey. can we get som circuit suggestions?
New Cheat Sheet Alert!
Level up your data organization and access skills in MATLAB with our latest cheat sheet! Download the full cheat sheet on MATLAB GitHub for Students here.