Picker value on V Sysex

Question

MIDI Target Manufacturer(s): Yamaha

Hello,

I use Midi designer Pro 2 v 2.131

I try to use Picker with SYSEX.in order to change values from 00 00 to FF FF on V parameter

So I try Picker from 0 to 999 value

- properties # tick : 1000 ; Min -max 0-> 999

- MIDI Min-> Max : 0-> 999

It works very well but I found a bug about values on output after 127 picker value

127 Picker value send a : 7F 00 on V value ;

128 Picker value  send a  00 01   on V value .

I cannot  understand why 128 ticker value is not sending 80 00 value.

How can I manage to increase value 7F 00 to 80 00 on 1 tick on Picker design ?

Regards,

Answer 1

01 00 follows 00 7F in Midi data

Midi data is seven byte, not eight.  7F is the highest byte value.  Bytes beginning with 8_ and higher are reserved for Midi commands.

127 = 00 7F
128 = 01 00
etc.

If you want the control to cover the full 16383 range fro 00 00 to 7F 7F, you will need to use named ticks, best loaded from a spreadsheet.

Comments

Thank you for your reply.

You are right. Of course.

MIDI always transmit 8 bits bytes. The first bit indicates if this is a status byte (1) or a data byte (0).
But nethertheless, I cannot see the logic on the values on Picker.

- first , 127 = 00 7F  and the sending value by MIDI designer is  7F 00 with Picker value 127.
I try it with negative value and it begin with 01 00 so no change for the first value on Picker.

- second, the min /max value of Picker (-99 to 999) don't cover  the full 16383 range from 00 00 to 7F 7F ...

---

"If you want the control to cover the full 16383 range fro 00 00 to 7F 7F, you will need to use named ticks, best loaded from a spreadsheet."

The maximum range precoded for display values is -99 to +999.  The maximum number of precoded ticks is 1025.  To cover a full range of 0 to 16383, you have to build it in a spreadsheet and import as named ticks.  The simplest version is just a 0 to 16383, one on each line.

Since the highest number automatically displayed is 999, then you can add a custom display like:

0 \ 0 [00 00]
...
16383 \ 16,383 [7F 7F]

Negative values are meaningless in midi.  Depends on what a specific board has implemented.  Search for other posts on QA for negative implementations.

---

I try it ... it works.

Thank you for the trick.

Answer 2

01 00 follows 00 7F in Midi data

Midi data is seven byte, not eight.  7F is the highest byte value.  Bytes beginning with 8_ and higher are reserved for Midi commands.

127 = 00 7F
128 = 01 00
etc.

If you want the control to cover the full 16383 range fro 00 00 to 7F 7F, you will need to use named ticks, best loaded from a spreadsheet.