You're in luck! MATLAB and Arudino support is very well documentated here. What it boils down to is just replacing classic Arduino IDE functions with their MATLAB equivalent, such as digitalread with readDigitalPin. I've gone ahead and done a rough translation of the code you attached and it should work but I do not have an arudino with me to test it with.
MOTION_PIN = 2; %% Pin connected to motion detector
LED_PIN = 13; %% LED pin - active-high
a = arduino('COM4','Uno')
%% The PIR sensor's output signal is an open-collector,
%% so a pull-up resistor is required:
pinMode(MOTION_PIN, INPUT_PULLUP);
configurePin(a,MOTION_PIN,'Pullup')
configurePin(a,LED_PIN, 'DigitalOutput');
while 1
proximity = readDigitalPin(a,MOTION_PIN);
if (proximity == 0) %% If the sensor's output goes low, motion is detected
{
writeDigitalPin(a,LED_PIN, 1);
disp('Motion detected!');
}
else
{
writeDigitalPin(a,LED_PIN, 0);
}
end
end
