Question

Second day trying to get the character from byte value which was scaled by 0x40 bytes

I’m trying to get hex value from Logic Pro/Mackie Control.

Logic sends me 0xE, it mean this is ‘n’. If it sends me ‘4e’ it mean I should draw on the display ‘n.’ (simply add dot at the end).

Here is formula for converting char to byte. Please help me made vice versa formula.

char translate_seven_segment( char achar )
{
    achar = toupper( achar );
    if ( achar >= 0x40 && achar <= 0x60 )
        return achar - 0x40;
    else if ( achar >= 0x21 && achar <= 0x3f )
        return achar;
    else
        return 0x00;
}

char s = 'N';
    Byte ad = translate_seven_segment( s ) + ( '.' == '.' ? 0x40 : 0x00 );

I found also following code (this seems without topper()):

def translate_seven_segment( char )                      
    case char                                       
      when 0x40..0x60                                   
        char - 0x40                                     
      when 0x21..0x3f                                    
        char                                         
      else                                        
        0x00                                         
    end                                        
  end   

How I can reverse it ? I know mackie use this code to build hex from char. But I need vise versa, is to get char from hex.

Answer 1

OK, I see you added the note about wanting to reverse the sequence. If that’s the case it’s fairly simple:

BOOL haveDot = (the7Segment & 0x40) != 0;
char temp = the7Segment & 0xBF;
char theChar = (temp > 0x21) ? temp : (temp + 0x40);