Controlling a PWM Fan with Matlab using Arduino

Hello everyone,

i have to control a PWM Fan with arduino using matlab.

First i connected external 12V to the fan and it rotates at it's max.

second i connected the PWM's fan to my arduino PWM pin (5)

i opened GUI in Matlab and added two Pusch buttons for one ON and the other for OFF

i used the code writeDigitalPin(a,'D5',0) and write PWMVoltage(a,'D5',0) but both didn't work..

do you have any idea how to control the fan using PWM? to let it rotate and stop and change the speed?

thanks in advance

function varargout = yarabb(varargin)
% YARABB MATLAB code for yarabb.fig
%      YARABB, by itself, creates a new YARABB or raises the existing
%      singleton*.
%
%      H = YARABB returns the handle to a new YARABB or the handle to
%      the existing singleton*.
%
%      YARABB('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in YARABB.M with the given input arguments.
%
%      YARABB('Property','Value',...) creates a new YARABB or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before yarabb_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to yarabb_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help yarabb

% Last Modified by GUIDE v2.5 24-May-2022 10:57:56

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @yarabb_OpeningFcn, ...
                   'gui_OutputFcn',  @yarabb_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before yarabb is made visible.
function yarabb_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to yarabb (see VARARGIN)

% Choose default command line output for yarabb
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes yarabb wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = yarabb_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;
clear all;
global a;
a = arduino();


% --- Executes on button press in Clockwise.
function Clockwise_Callback(hObject, eventdata, handles)
% hObject    handle to Clockwise (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global a;
writeDigitalPin(a,'D5',1);
%writePWMVoltage(a,'D5',5);
pause(0.5);

% --- Executes on button press in Anti.
function Anti_Callback(hObject, eventdata, handles)
% hObject    handle to Anti (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global a;
writeDigitalPin(a,'D5',1);
pause(0,5)


% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global a;
writeDigitalPin(a,'D5',0);%i set the pin 5 to 0 but it still rotates when i push the stop button
%writePWMVoltage(a,'D5',0); % i tried also with this code but it didnt work
pause(0.5);

[Bishoy Iskandar]

Hello everyone,

Hello everyone,

i connected the Fan with 5V from Arduino and not the external 12V and it has stopped with my code but when it rotates it rotates at it's minimun now because it becomes only 5V..

How can i make it stop rotating within the 12V connected to it and not the 5V?

Thanks in Advance..

Answer 1

[Aman Banthia]

Hi Bishoy,

I understand that you are trying to control the speed of your fan with the help of Arduino while connected to an external 12V power supply.

To control a fan with a 12V external input using a relay, transistor, and a potentiometer with Arduino, you can follow these steps:

1. Connect the 12V external power source to the fan.

2. Connect the control pin of the relay or transistor to a digital output pin on the Arduino.

3. Connect the potentiometer to an analog input pin on the Arduino. The potentiometer will act as a voltage divider to control the speed of the fan.

4. In your MATLAB code, use the `writeDigitalPin` function to control the relay or transistor. Set the pin to HIGH to activate the relay or transistor and provide power to the fan and set it to LOW to deactivate the relay or transistor and cut off power to the fan.

For example:

writeDigitalPin(a, 'D5', 1); % Activate the relay or transistor to provide power to the fan
  
writeDigitalPin(a, 'D5', 0); % Deactivate the relay or transistor to cut off power to the fan

5. Use the `analogRead` function in MATLAB to read the value from the potentiometer connected to the analog input pin. This value will determine the speed of the fan.

For example:

potentiometerValue = analogRead(a, 'A0'); % Read the value from the potentiometer connected to analog pin A0

6. Map the potentiometer value to a suitable range for the fan speed control. This can be done using the `map` function in MATLAB.

For example:

fanSpeed = map(potentiometerValue, 0, 1023, 0, 255); % Map the potentiometer value to a range suitable for the fan speed control (0-255)

7. Use the `analogWrite` function in MATLAB to control the speed of the fan using PWM. Set the speed value obtained from the mapping step.

For example:

analogWrite(a, 'D6', fanSpeed); % Control the speed of the fan using PWM on digital pin D6

By following these steps, you can control the fan's power using the relay or transistor and adjust its speed using the potentiometer connected to the Arduino. Ensure that the relay, transistor, and potentiometer are appropriately connected and compatible with the voltage and current requirements of the fan and the Arduino board.

Please refer to the following MATLAB documentation to know more about the functions used in MATLAB Support Package for Arduino:

https://in.mathworks.com/help/supportpkg/arduinoio/index.html

Hope the above solution helps you.

Best Regards,

Aman Banthia