MATLAB: ThingSpeak Channel Table Error

MATLABtableThingSpeak

Hi everyone,

I am having issues with my ThingSpeak Channel only displaying certain portion of my table. When I run the visualization code on its own, I get the full table as shown here:

However, when I refresh the page to check the ThingSpeak channel, only the last row of the table is displayed.

I have tried to adjust the Display Settings on the Visualization side, but I am still getting the same issue. I have attached my code to the bottom of this post for any clarity.

Any help would be appreciated!

Best Answer

I suggest using a timetable. The uitable element is really not right for ThingSpeak.

dataTimeTable = ...
    thingSpeakRead(channelId, 'OutputFormat','TimeTable','NumPoints',3,'ReadKey',readAPIKey)

Then use the second suggestion in this answer.

I did it for some traffic monitor data.

myCarData = thingSpeakRead( 38629,'numpoints',3,'outputFormat','TimeTable' );
TString = evalc('disp(myCarData)');
TString = strrep(TString,'<strong>','\bf');
TString = strrep(TString,'</strong>','\rm');
TString = strrep(TString,'_','\_');
FixedWidth = get(0,'FixedWidthFontName');
% Output the table using the annotation command.
annotation(gcf,'Textbox','String',TString,'Interpreter','Tex',...
    'FontName',FixedWidth,'Units','Normalized','Position',[0 0 1.5 1],'FontSize',7);

I had to change the font size to get thigns to fit due to the long field names. You might be able to make that larger.

Related Solutions

MATLAB: How to display a MATLAB table in a figure

You can either use "uitable" or a more complicated series of commands depending on how you want the table to look.

For example, let us assume you have a table defined by the following code:

LastName = {'Smith';'Johnson';'Williams';'Jones';'Brown'};
Age = [38;43;38;40;49];
Height = [71;69;64;67;64];
Weight = [176;163;131;133;119];
T = table(Age,Height,Weight,'RowNames',LastName);

1.) If you want the table to have adjustable-width columns and a more stylized look, execute the following "uitable" command to display the table "T" in a figure:

uitable('Data',T{:,:},'ColumnName',T.Properties.VariableNames,...
    'RowName',T.Properties.RowNames,'Units', 'Normalized', 'Position',[0, 0, 1, 1]);

You can refer to the following documentation link for more information on "uitable":

https://www.mathworks.com/help/matlab/ref/uitable.html

2.) If you want the table to look very similar to how it looks when outputted in the MATLAB command window, execute the following series of commands to display the table "T" in a figure:

% Get the table in string form.
TString = evalc('disp(T)');
% Use TeX Markup for bold formatting and underscores.
TString = strrep(TString,'<strong>','\bf');
TString = strrep(TString,'</strong>','\rm');
TString = strrep(TString,'_','\_');
% Get a fixed-width font.
FixedWidth = get(0,'FixedWidthFontName');
% Output the table using the annotation command.
annotation(gcf,'Textbox','String',TString,'Interpreter','Tex',...
    'FontName',FixedWidth,'Units','Normalized','Position',[0 0 1 1]);

You may find the following documentation links useful:

https://www.mathworks.com/help/matlab/ref/evalc.html

https://www.mathworks.com/help/matlab/ref/strrep.html

https://www.mathworks.com/help/matlab/ref/annotation.html

MATLAB: Error using thingSpeakWrite Expected a string scalar or character vector for the parameter name.

Isnt this the API ? You missed the 'WriteKey' key in your API call?

thingSpeakWrite(channelID, data, 'WriteKey', writeAPIKey)

Best Answer

Related Solutions

MATLAB: How to display a MATLAB table in a figure

MATLAB: Error using thingSpeakWrite Expected a string scalar or character vector for the parameter name.

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