Some bitshifting help needed

Projects Programming
1

Hello,

I need a little programming help.

I have a 16bit integer, and i would like to convert it to two 8 bit integers

Here is the function, but this doesn't work well, could anybody help me?

void SendPitchBend(uint8_t Ch,uint16_t Val) 
{
  MidiMsg Message;
  Message.D1=0xE;
  Message.D1=((Message.D1<<4)|Ch);
  
  Message.D2=Val;
  Message.D3=Val>>8;
  
  SendMidiMsg(&Message);
}

But not just separating them, here is an example:

4240 = 0001 0000 1001 0000

D2 should be 0010 0001
D3 should be 0001 0000

The MidiMSG structure looks like this:

struct MidiMsg
{
  union
  {
    struct { 
      uint8_t D1, D2, D3; 
    };
    uint8_t Raw[3];
  };
};
2

Problem solved

3

Problem solved

Good. I guess it doesn't really matter what the problem was or how you solved it.

4

The problem was My stupidity (confusing MSB and LSB), and here is the solution:

void SendPitchBend(uint8_t Ch,uint16_t Val) 
{
  MidiMsg Message;
  Message.D1=0xE<<4|Ch;
  Message.D2=Val<<1;
  Message.D2=Message.D2>>1;
  Message.D3=Val>>7;
  SendMidiMsg(&Message);
}

Maybe the part where Message.D2 gets its value, could be done in 1 command, but i haven't figured it out how

Also, this method possibly won't work in all situations, because my initial 16 bit integer contains only max. 14 bit numbers, and D2&D3 should represent that number in two 7 bit parts, the MSB in each byte will be always 0.

This is a soluion for sending pitch bend data over midi, and it is a bit overcomplicated i think, because the Pitch Bend message includes two data bytes to specify the pitch bend value. The two bytes of the pitch bend message form a 14 bit number ( 0 to 16383 ).

EDIT: The part where I give value to Message.D2 possibly could be done like this:

  Message.D2=Val & 0x7F;

I found this solution in an already existing MIDI library, but haven't tested it yet.

5

The problem was My stupidity (confusing MSB and LSB)

It's not stupidity unless you persist in not learning. Seems to me that you did learn something.