function values = cmd_digital_in(h,pin_no)
// Command to read in digital signal from a connected Arduino board
//
// Calling Sequence
//      values = cmd_digital_in(h,pin_no)
//
// Parameters
//     h : Board number, reserved for future use. For this version, any number would do
//     pin_no : Digital pin to measure the signal
//
// Description
//     The Arduino board has a set of logical ports (digital) that are used for writing or reading data from a component.
//
//     To map a UNO, ports 2-13 are available (0 and 1 are used for serial transmission). For MEGA board, ports 2-53 are available. The port takes the low logic level (0) or logic high (1) which corresponds to the reference voltage.
//  
// Examples
//     ok = open_serial(1,9,115200) 
//     val = cmd_digital_in(1,2) 
//     close_serial(1)
// 
// See also
//    cmd_digital_out
//    
//
// Authors
//     Bruno JOFRET, Tan C.L. 
//    

if isvector(pin_no)
    for cnt = 1: size(pin_no,2)
        pin="Da"+ascii(48+pin_no(cnt))+"0";
        write_serial(h,pin,4);
         pin="Dr"+ascii(48+pin_no(cnt));
          write_serial(1,pin,3);
       //binary transfer
      [a,b,c]=status_serial(h);
       while (b < 1) 
        [a,b,c]=status_serial(h);
      end
      values(cnt)=strtod(read_serial(h,1));
    end
else
pin="Da"+ascii(48+pin_no)+"0";
write_serial(h,pin,4);
     pin="Dr"+ascii(48+pin_no);
      write_serial(1,pin,3);
      //binary transfer
      [a,b,c]=status_serial(h);
      while (b < 1) 
        [a,b,c]=status_serial(h);
      end
      values=strtod(read_serial(h,1));
end
      
endfunction