Please use the following steps to modulate the four LEDs with different frequencies using MATLAB:
Define the frequency values for each LED as variables:
f1 = 1000; % frequency of LED 1
f2 = 1250; % frequency of LED 2
f3 = 1750; % frequency of LED 3
f4 = 2000; % frequency of LED 4
Define the sampling rate and the duration of the modulation signal:
Fs = 8000; % sampling rate
t = 0:1/Fs:1; % duration of modulation signal (1 second)
Create the modulation signals for each LED using the sine function and create a matrix to hold these signals:
mod1 = sin(2*pi*f1*t);
mod2 = sin(2*pi*f2*t);
mod3 = sin(2*pi*f3*t);
mod4 = sin(2*pi*f4*t);
modulation = [mod1; mod2; mod3; mod4];
Initialize the LEDs using the Arduino interface in MATLAB:
a = arduino();
led1 = 'D3'; % digital pin connected to LED 1
led2 = 'D5'; % digital pin connected to LED 2
led3 = 'D6'; % digital pin connected to LED 3
led4 = 'D9'; % digital pin connected to LED 4
configurePin(a, led1, 'DigitalOutput');
configurePin(a, led2, 'DigitalOutput');
configurePin(a, led3, 'DigitalOutput');
configurePin(a, led4, 'DigitalOutput');
Loop through the modulation signals for each LED and turn the corresponding LED on and off based on the signal value:
for i = 1:length(t)
if modulation(1,i) > 0
writeDigitalPin(a, led1, 1);
else
writeDigitalPin(a, led1, 0);
end
if modulation(2,i) > 0
writeDigitalPin(a, led2, 1);
else
writeDigitalPin(a, led2, 0);
end
if modulation(3,i) > 0
writeDigitalPin(a, led3, 1);
else
writeDigitalPin(a, led3, 0);
end
if modulation(4,i) > 0
writeDigitalPin(a, led4, 1);
else
writeDigitalPin(a, led4, 0);
end
pause(1/Fs);
end
This code will continuously loop through the modulation signals for one second, turning each LED on and off based on the corresponding signal value.
