MATLAB libraries of DHT11 sensor

@ MathWorks MATLAB Hardware Team

If the DHT11 sensor is connected to my Arduino and I want to read the temperature and humidity data directly from that pin of Arduino to which it is attached without the help of any arduino code, is there any Matlab library available for that?

[MathWorks MATLAB Hardware Team]

Hi Sadiq,

Kindly reach out to MathWorks Technical Support to get help in resolving your query

https://www.mathworks.com/support/contact_us.html

Answer 1

[Walter Roberson]

No, there is no MATLAB library for that.

However if you are using Simulink, see https://www.mathworks.com/matlabcentral/fileexchange/62878-arduino-additional-sensors-library-dht-lps331

Otherwise,

https://www.mathworks.com/matlabcentral/answers/521420-i-want-to-interface-with-the-dht11-sensor-in-matlab-but-program-give-this-error-subscripted-assignm

[Sadiq Akbar]

Thank you very much dear Walter Roberson for your prompt response. I have visited that earlier and I have tried that too but that doesn' work.

[Sadiq Akbar]

I have modefied that code like below:

clc
clear all

delete(instrfindall);
close(instrfindall);

s = serial('COM5');
time=100;
i=1;
while(i<time)

    fopen(s)
    fprintf(s, 'Your serial data goes here')
    out = fscanf(s)
    
    Temp(i)=str2double(out(1:4));% Temp(i)=str2num(out(1:4));
    subplot(211);
    disp(Temp(i))% By Me
    plot(Temp(i),'g');% plot(Temp,'g');
    axis([0,time,10,50]);
    title('Parameter: DHT11 Temperature');
    xlabel('time');
    ylabel('Temperature');
    grid
    
    
    Humi(i)=str2double(out(5:9));
    subplot(212);
    disp(Humi(i))% By Me
    plot(Humi(i),'m');
    axis([0,time,10,100]);
    title('Parameter: DHT11 Humidity');
    xlabel('time');
    ylabel('% of Humidity');
    grid
    
    fclose(s)
    i=i+1;
    drawnow;
end
delete(s)
clear s

But when I execute it in debugger mode, and I check the variable out, tooltp shows: out: 1 x 20 char=

Temperature: 18.00

Likewise when I check Temp(i), the debgger shows in tooltip as:

Temp: 1 x 20 double=

NaN

Also no any graph is displayed.

[Sébastien Josset]

Hi! The answer would interest me as well :) When using Sadiq's modified code, I get:

Warning: Unsuccessful read: A timeout occurred before the Terminator was reached.

'serial' unable to read all requested data. For more information on possible reasons, see Serial Read Warnings.

out =

'nannannannannannannannan'

NaN

NaN

Some help would be great!

Sebi

[Walter Roberson]

If "out" is showing Temperature: 18.00 then the implication is that the data sent by the other side is not just numeric. If you know for sure that the "Temperature:" part is always going to be there then you can use fscanf() with a format of 'Temperature: %f' to read the numeric part directly, but if there might be a variety of text then you need to analyze the text to figure out which format to use.