Hi Dave and others,
This subforum seemed a bit empty I decided to fill it up a bit.
First project I want to show off is a programmable audio-router, the heart of a multi-effect rackmount guitar preamp which is still a work-in-progress. The core of the router is a 16x16 matrix chip, the AD75019 by Analog Devices. I didn't want a big-@ss user interface or display, it needed to be robust and preferably stage-proof, but I still want reconfigurability during rehearsals, if needed. Live it's going to be remote controlled by MIDI.
The router hardware is described on the diystompboxes forum:
https://www.diystompboxes.com/smfforum/index.php?topic=112598.msg1137713#msg1137713
It uses a 16x2 LCD and one encoder. In play mode it shows the current program in big numbers + name, plus a few parameters. Rotating the encoder goes through presets, pressing the encoder goes to the menu where you can edit the settings for this preset, plus a submenu for global parameters.
The routing-editor works as follows: there's a number of "patchcables", for each of the patchcables you can define the "from" and the "to". The guitar-input is a "from" and the output to the poweramp is a "to". All effects are hardcoded (their name and their I/O config of the matrix) and they all can function as a "from" and as a "to".
When you change the "cable" menu, the corresponding "from" and "to" enumerated menus change to the currently configured values for that cable. Then you can change these from and to values as needed. It takes a little brain gymnastics to imagine the whole chain in your head, but it works! If I had used a TFT, it would be easier to see the cables as you scroll through them, but to fit that in a 1HE rack would be too tiny to read so it had to be the LCD.
Finally, a bit of the menu-ing in action, demoing the cabling described above (warning: loud music!)
https://www.youtube.com/watch?v=WrM7nGUyoXQ
In the end of the clip you can see the switches in the matrix output to the serial port as ones in a square of zeroes.
Attached: work-in-progress on the bench.