CODEWITHSUNDEEP
matlabarduino
MyNick
MyNick

Reputation: 556

Matlab and Arduino

Im trying to test communication between matlab and arduino and something weird happen. I try the numbers 1 to 10 to receive them back. It works for 2,3,4....10 but for 1 i get:

Warning: Unsuccessful read: The specified amount of data was not returned within the Timeout period.

If i run it again i get the same results. for 1 i get error and i get 2 to 10. I dont reset the arduino between runs. Thats the weird part.

My arudino code:

uint32_t next_number;

void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  pinMode(13, OUTPUT);
  digitalWrite(13, LOW);
  next_number = 0;
}

void loop() {
  if (Serial.available() >= sizeof(next_number)) {
    uint8_t data_read = Serial.readBytes((uint8_t*)&next_number, sizeof(next_number));
    Serial.write((uint8_t*)&next_number, 4);
    digitalWrite(13, HIGH);
  }
}

My Matlab code:

function send_song_to_arduino()
    delete(instrfind);
    s = serial('COM3');
    disp(['s input buffer size ', num2str(s.InputBufferSize)]);
    set(s,'Terminator','LF'); % define the terminator for println
    set(s,'Databits',8);
    set(s,'Stopbits',1);
    set(s,'Parity','none');
    set(s, 'BaudRate', 9600);
    fopen(s);
    disp(['available at start ', num2str(s.bytesavailable)]);
    disp(['left to send at start ', num2str(s.BytesToOutput)]);
    if (s.bytesavailable > 0)
        fread(s, s.bytesavailable, 'uint8')
    end
    disp('starting');
    for i=1:10
        fwrite(s, i, 'uint32');
        pause(1);
        disp(['available ', num2str(s.bytesavailable)]);
        received = fread(s, 1, 'uint32');
        disp(['recv ', mat2str(received)]);
    end
    disp(['done available ', num2str(s.bytesavailable)]);
    disp(['total sent ', num2str(s.ValuesSent)]);
    disp(['left to send at end ', num2str(s.BytesToOutput)]);
    fclose(s);
    delete(s);
end

Results:

>> send_song_to_arduino
available at start 0
left to send at start 0
starting
available 0
Warning: Unsuccessful read: The specified amount of data was not returned within the Timeout period. 
recv zeros(1,0)
available 4
recv 2
available 4
recv 3
available 4
recv 4
available 4
recv 5
available 4
recv 6
available 4
recv 7
available 4
recv 8
available 4
recv 9
available 4
recv 10
done available 0
total sent 10
left to send at end 0

Upvotes: 0

Views: 249

Answers (1)

MyNick
MyNick

Reputation: 556

My solution: Apperently, matlab serial open resetting the arduino. The serial on the arudino side take some time to start so the first request is sent before the arduino is ready. I just added a pause after the fopen.

Upvotes: 0

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