Arduino serial communication with Matlab (DAQ, getting maximum sample rate)

Hello everyone

I am trying to create DAQ software in Matlab which reads data from Arduino 2560 analog pin at maximum possible speed and plot data in real time. However I cant get sample rate higher than 50 Hz. I have been browsing the internet and trying to find a solution without succes so far.

Here is the Arduino code. It should be able sample at rate aroun 8 kHz (serial monitor). I kept it simple so I would achieve maximum speed.

      void setup() {
     // start the connection to the device over the USB host:

    //Serial.begin(500000); I have tried different baud rates suggested at forums
    Serial.begin(115200);
    }
  void loop() {

        int analogValue = analogRead(A0) ;

        Serial.println(analogValue);
        // delay(15); without delay(15) error occurred in matlab while reading data
   }

Here is simplified Matlab code. I'm just trying to collect as much data as i possibly can. So far i got 642 samples / 10s.

clear all
close all
clc
priorPorts = instrfind; % finds any existing Serial Ports in MATLAB
delete(priorPorts); % and deletes them

%User Defined Properties 
serialPort = 'COM3';            % define COM port #
s = serial(serialPort,'BaudRate',115200);
fopen(s);
figure
pause(1)
i=1;
tic;
while toc<=10 %collect data for 10s

       dat = fscanf(s, '%d')';
       data(i)=dat;
       time(i)=toc;
       %dat = fread(s,100)'; % fread didnt work (oscilating from 13 to 50)
       plot(time,data,'--rs','LineWidth',2,...
                  'MarkerEdgeColor','k',...
                  'MarkerFaceColor','g',...
                  'MarkerSize',10);
   drawnow;
  i=i+1;
  end
  priorPorts = instrfind; % finds any existing Serial Ports in MATLAB
  delete(priorPorts); % and deletes them
   disp('end');

Is there a way to read all samples sent by Arduino or are there any inner Matlab limits?

Any help would be greatly appreciated

[Sonomatic Australia]

Any luck with this?

[Walter Roberson]

Are you using a real serial port all the way, or are you using USB?

Answer 1

[enes kuzucu]

it is possible to read at 100 hz .I dont know the limits tho. But quality and the resolition is changing.