Character Display Control

Design Concepts
1

This is a long shot, but I’m going to ask anyway. Is it possible to control 1 character LCD from 2 Core32 units?

I am trying to add a midi I/O to an old Hammond organ. I need 2 Core32 units because there are too many

keys/buttons/switches to be controlled from one core (a total of about 200). I am using a display to show the

midi channel the manual/pedals/stops are set to and if anything is being transposed. The problem is, I really

don’t want 2 displays. Here is the layout of the displays so you can get an idea of what I have and what I want.

What I have: 1st display

----Upper Manual----

Chan: 1 Trans: 0

----Lower Manual----

Chan: 2 Trans: 0

2nd display

-------Pedals-------

Chan: 3 Trans: 0

-------Stops--------

Chan: 4

What I want:

Upper Manual: Chan: 1 Trans: 0

Lower Manual: Chan: 2 Trans: 0

Pedals: Chan: 3 Trans: 0

Stops: Chan: 4

Is this at all possible? Thanks in advance for any help.

2

Short answer: No.

Long answer: Yes, with added circuitry.

Then again, you can have a lot more inputs on a single core32 if you use a scan matrix.

3

Could you suggest a way to approach using a matrix, possibly a tutorial or completed program I can use as a starting point?

4

See this thread:

http://discourse.midibox.org/t/topic/14882

4 manuals of an organ controlled from a single BLM16x16+X based application running on the PIC.

The code can be found here: http://svnmios.midibox.org/listing.php?repname=svn.mios&path=%2Ftrunk%2Fapps%2Fcontrollers%2Fblm_scalar_4x8x8_buttons%2F

The same could be ported to MIOS32 as the BLM_SCALAR library exists for Core32 as well:

http://svnmios.midibox.org/listing.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2Fcontrollers%2Fblm_scalar%2F

Best Regards, Thorsten.

5

Thanks for the help. This is exactly what I was looking for. I have just a few more issues.

  1. How do I set which DIN and DOUT shift registers are used by the matrix?

  2. Is the circuit design for the example program the same as the one used by Wilba for his MIDIbox SID,

and do the switches send the inputs low or high when pushed.

  1. Are the buttons in the matrix counted from 0 or 1?

  2. How do I specify the DIN pins to use for rotary encoders? Am i correct in assuming that in the tutorial

code for relative rotary encoders, enc_config.cfg.sr is the shift register the encoder is attached to, and

that enc_config.cfg.pos is the pin on that register the encoder is attached to?