So Many Questions... mux... encoders... OSC

Hello There,
I have 2 zynthians, one 3B and 5" GIPO screen one 3B+ and HDMI 7" screen, encoders connected directly to the GPIO pins and working fine…
Here’s a little fun jam I did with the 3B+ (which also have embedded battery cell, amp+speaker) for last weekend Hardware Jam Challenge (a group on FB) which topic was 007. Execution is not perfect but the ZynSeq is really a great addition and makes it easier to play .

So far so good… but I just ordered a zynaptic 2 to get my Zynthian synced in MIDI to my other gear and maybe send/receive CV/gate. I found out I will certainly lack some GPIO pin to plug all encoders (and what about a sound card or the 5 inch screen ?) .

Should I install another MCP23017 ? Did anybody tried to use some 74hc4067 multiplexers ?
I also would like to add a couple of extra buttons to access the sequencer and extra encoders to have some functions accessible instantly.

I have been tempted by the zynscreen but was afraid of the screen size, drawing notes on a 7" screen is already a bit tricky, on the 5" I have to use a needle so I guess it must be done with the encoders on a 3,5".

Also is there some way to implement OPEN STAGE CONTROL ? This is the ultimate tool to make an OSC modular MIDI controller.

Thanks a lot anyway for making this box real, it is fun and powerful.
Have a nice day


Oh and Ableton Link would be nice… is there something in the pipe ?

Nice box you built there!

I’m trying to build something similar. Could you help me sharing some photos of the inside and the components you used?

Hi @b_a_t! Welcome to the community. That is a really nice bit of music - well done. I see you are suffering low voltage. You will want to improve your power supply / cabling to reduce the risk of clicks on output.

I won’t answer the MCP question - I think others may be better placed.

Using a stylus with ZynSeq on a 3.5" screen works okay although sometimes the screen membrane is so loose that it results in bad registration with is frustrating. I think I find the stylus and small screen a bit easier than finger and larger screen but would prefer to use the larger screen, especially if I could use a stylus. I don’t have a suitable stylus for my 7" capacative screen.

OSC is already implemented. It remains a work in progress but you can already do many things with it. Check out the wiki.

I am not aware of any work on implementing Ableton Link. I haven’t looked into it before but see it is available on GitHub. If you add a feature request with some good use cases then maybe someone might pick up the batton.