ThingSpeak don't update channel automatic

Hello, in a ThingSpeak channel, I am reading every one second the information of two current signals (I have the licensed application).

I currently have a MATLAB Analysis routine that adds those two signals and writes, on the same channel, the result of that sum. In the routine I can check that effectively if the sum of the two channels is being done.

I do that now with a good result but my problem is that the channel is not updated except when I run MATLAB Analysis.

How can I make the channel automatically update every second?

-------------------------------------------------------------------------------

This is my routine:

readChannelID = 123;
readAPIKey = 'XXX';
writeChannelID = 123;
writeAPIKey = 'YYY';

%%%%%%%%%%%%%%%%%%%%%%  CALCULO DE CORRIENTE  %%%%%%%%%%%%%%%%%%%%%%  
[Cte1, timeStamp] = thingSpeakRead(readChannelID,'Fields',1,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Cte1));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Cte1),2));
    cleanCte1 = Cte1(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanCte1 = Cte1;
    cleanTimeStamps = timeStamp;
end

[Cte2, timeStamp] = thingSpeakRead(readChannelID,'Fields',4,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Cte2));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Cte2),2));
    cleanCte2 = Cte2(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanCte2 = Cte2;
    cleanTimeStamps = timeStamp;
end

Corriente = round([cleanCte1 + cleanCte2],1);
display (Corriente, 'Corriente')

%%%%%%%%%%%%%%%%%%%%%%  VOLTAJE  %%%%%%%%%%%%%%%%%%%%%%  
[Voltaje, timeStamp] = thingSpeakRead(readChannelID,'Fields',2,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Voltaje));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Voltaje),2));
    cleanVoltaje = Voltaje(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanVoltaje = Voltaje;
    cleanTimeStamps = timeStamp;
end

display (cleanVoltaje, 'Voltaje')

%%%%%%%%%%%%%%%%%%%%%%  CALCULO DE POTENCIA  %%%%%%%%%%%%%%%%%%%%%%  
Potencia = round([Corriente * cleanVoltaje],0)

%%%%%%%%%%%%%%%%%%%%%%  CALCULO DE ENERGIA  %%%%%%%%%%%%%%%%%%%%%%  
[Energia1, timeStamp] = thingSpeakRead(readChannelID,'Fields',3,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Energia1));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Energia1),2));
    cleanEnergia1 = Energia1(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanEnergia1 = Energia1;
    cleanTimeStamps = timeStamp;
end

[Energia2, timeStamp] = thingSpeakRead(readChannelID,'Fields',5,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Energia2));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Energia2),2));
    cleanEnergia2 = Energia2(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanEnergia2 = Energia2;
    cleanTimeStamps = timeStamp;
end

Energia = [cleanEnergia1 + cleanEnergia2];
display (Energia, 'Energia')

%%%%%%%%%%%%%%%%% Write the results in fields 6, 7 and 8 of the same channel %%%%%%%%%%%%%%%%%%%%    
thingSpeakWrite(writeChannelID, 'Fields', [6,7,8], 'Values',...
    [Corriente, Potencia, Energia],'WriteKey',writeAPIKey);

OUTPUT:

Corriente = 3.4000

Voltaje = 116

Potencia = 394

Energia = 0.0040

Answer 1

[Sergio R]

I have followed your advice and it actually works. The channel is already updated automatically.

thanks for your help

Answer 2

[Hans Scharler]

I would write to a second ThingSpeak channel instead of writing data back to the same channel. The reason is that ThingSpeak will overwrite other fields with nulls for the fields that do not have a value. I think that you are writing to the 6,7,8 fields, then your channel updates and overrides their data with nulls.

Also, you can read an entire channel's worth of data in one thingSpeakRead request. This will speed up your script.

[Sergio R]

Hi Hans,

I already made the change you suggested, but it does not work either.

The values are not updated automatically, except when I give "Save and run" to the application.

In a first channel (AAAA) I read two current signals, two Voltage signals, two power signals and two energy signals, then I write them the result of the sum of the current, power and energy in a new channel (BBBB) .

At the exit of the application I can assure you that there are indeed valid values for each variable.

How to make the values automatically update?

readChannelID = AAAAA;
readAPIKey = '12345678';

%%%%%%%%%%%%%%%%%%%%%%  READ CURRENT IN CHANNEL AAAAA, Fields 1 & 5  %%%%%%%%%%%%%%%%%%%%%%  
%%%%%%%%%%%%%%%%%%%%%%                CURRENT CALCULATION             %%%%%%%%%%%%%%%%%%%%%%  

[Cte1, timeStamp] = thingSpeakRead(readChannelID,'Fields',1,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Cte1));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Cte1),2));
    cleanCte1 = Cte1(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanCte1 = Cte1;
    cleanTimeStamps = timeStamp;
end

[Cte2, timeStamp] = thingSpeakRead(readChannelID,'Fields',5,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Cte2));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Cte2),2));
    cleanCte2 = Cte2(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanCte2 = Cte2;
    cleanTimeStamps = timeStamp;
end

Corriente = round([cleanCte1 + cleanCte2],1);
display (Corriente, 'Corriente')

%%%%%%%%%%%%%%%%%%%%%%       READ VOLTAGE IN CHANNEL AAAAA  Field 2  %%%%%%%%%%%%%%%%%%%%%%  
%%%%%%%%%%%%%%%%%%%%%%                VOLTAGE CALCULATION             %%%%%%%%%%%%%%%%%%%%%% 
[Voltaje, timeStamp] = thingSpeakRead(readChannelID,'Fields',2,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Voltaje));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Voltaje),2));
    cleanVoltaje = Voltaje(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanVoltaje = Voltaje;
    cleanTimeStamps = timeStamp;
end

display (cleanVoltaje, 'Voltaje')
 
%%%%%%%%%%%%%%%%%%%%%%                POWER CALCULATION             %%%%%%%%%%%%%%%%%%%%%%  
Potencia = round([Corriente * cleanVoltaje],0)

%%%%%%%%%%%%%%%%%%%%%%  READ ENERGY IN CHANNEL AAAAA, Fields 4 & 8  %%%%%%%%%%%%%%%%%%%%%%  
%%%%%%%%%%%%%%%%%%%%%%                ENERGY CALCULATION             %%%%%%%%%%%%%%%%%%%%%% 
[Energia1, timeStamp] = thingSpeakRead(readChannelID,'Fields',4,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Energia1));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Energia1),2));
    cleanEnergia1 = Energia1(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanEnergia1 = Energia1;
    cleanTimeStamps = timeStamp;
end

[Energia2, timeStamp] = thingSpeakRead(readChannelID,'Fields',8,'numPoints', 2, 'ReadKey', readAPIKey);
anyMissingValues = sum(isnan(Energia2));

if sum(anyMissingValues) > 0
    missingValueIndex = find(~sum(isnan(Energia2),2));
    cleanEnergia2 = Energia2(missingValueIndex, :);
    cleanTimeStamps = timeStamp(missingValueIndex);
else
    cleanEnergia2 = Energia2;
    cleanTimeStamps = timeStamp;
end

Energia = [cleanEnergia1 + cleanEnergia2];
display (Energia, 'Energia')

%%%%%%%%%%% Write the results in fields 1, 2, 3 & 4 in another channel (BBBBB) %%%%%%%%%%%%%%%%    
writeChannelID = BBBBB;
writeAPIKey = '12345678';

thingSpeakWrite(writeChannelID, 'Fields', [1,2,3,4], 'Values',...
    [Corriente, cleanVoltaje, Potencia, Energia],'WriteKey',writeAPIKey);

OUTPUT:

Corriente = 4.3000

Voltaje = 118

Potencia = 507

Energia = 0.0020

[Hans Scharler]

I see. This means that the MATLAB code is not scheduled to run automatically. At the bottom of the page, there is a place to add a TimeControl or a React. TimeControl will schedule your code to run and React will run the code based on a condition.

Answer 3

[Sergio R]

True. But the minimum control time is every 5 minutes. I need it to be every 1 or 2 seconds.

How can I make it update automatically every 1 or 2 seconds?

[Hans Scharler]

You can use React. Select "On data insert". This will cause the MATLAB code to run every time data gets sent to ThingSpeak.

[Thomas]

Hallo,

ich habe das gleiche Problem, allerdings kann man die Kontrollzeit nicht kürzer schalten lassen als 5 Minuten. Das ist in Matlab so fest gehalten.

Hier hilft nur ein Export in eine Cloud die die Daten dann sofort weiter leitet.

Grüße

Thomas