connection to arduino using bluetooth

hello

I am attempting to send some information from Matlab, to an Arduino Uno, via bluetooth with

matlab program

b=Bluetooth('HC-06',1);
fopen(b);
for i=1:1:15                                

fprintf(b,i); 
out(i) = fscanf(b,'%d');

end
 fclose(b)

and arduino program

int matlabval=0;

void setup()
{
Serial.begin(9600);
}

void loop()
{
   if (Serial.available() > 0) {
    matlabval=Serial.read();

Serial.println(matlabval); 

      }
  }

the output of arduino is

1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
10
10
11
10
12
10
13
10
14
10
15
10

the number 10 is appear after each number ?why?

Thanks in advance!

Answer 1

[Walter Roberson]

When you use

fprintf(b,i);

in MATLAB, because you did not specify a format, the default format used is '%s\n' . Each of your values for i is being converted using char() to become a character, and that is sent and then newline. Note that 1 would convert to char(1), the ASCII SOH (Start of Header) character, the one with binary value 1, not to '1', the digit 1, which is char(49) .

You should be considering using fwrite() instead of fprintf() if you want to send the values as binary, and if you want '1' and '2' and so on to be sent then you should use a format such as

fprintf(b, '%d\n', i)

You might need to adjust the read on the Arduino side.