What about a master volume control?
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this looks awesome! 
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Oooo there’s an idea …
That may be doable; I’m gonna have to look into whether there’s midi mapping for master I/O levels… you could definitely map master volume yourself to one of the MIDI pots if so. Problem is I’m out of analog pins available on a T4.0
@robint I definitely tossed around the idea of linear pots at some point but I realized I’d have to sacrifice a lot of panel real estate (to the tune of 3 rotary pots per fader) in order to make it happen, and even then I’m not sure I’d be able to comfortably fit the 60mm faders used in, say, 16n.
I honestly even considered pitch/mod style wheels, a small OLED screen & some keys for bank-switching, or even a Force Sensing Resistor with a linear softpot on top to have a ≈200mm aftertouch ribbon controller (creds to @nonverbalpoetry who actually built a functional DIY trautonium with this method) but in the end I decided to optimize for as many knobs as possible, plus I hit the aforementioned limitation on analog read pins. (I plan on building a 16n anyway cuz don’t get me wrong I love me some faders)
Honestly lots of ideas have ended up on the cutting room floor & as mentioned, this project has been a lovely case study in bloat & feature creep. I find myself having to rein in the scope of the project & really focus on what I want the object to be, and how it should serve the broadest possible set of use-cases
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WOW!!! 
just saw this topic!
be neat if all of the connections (MIDI, Audio, USB, etc.) could also fit on the top face. 
but it looks like that is all pretty full…so they would have to go around back.
excited to see where this goes!
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How are you planning on connecting the midi controller and the grid part of the device to the pi? Internal usb cables inside the case? And are you planning on exposing any of the pi’s original ports?
I’m in the process of designing a very very similar thing (although I ditched the last row of pots for 2 0.91" oled screens ) and an encoder to allow for page navigation and storing and editing of mappings.
16 knobs? That’s insane.
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This is utterly fantastic. Definitely following with much interest.
I was considering something verrry similar but dealing w/ pages & having mismatch between the pots & values on each page sounds like just asking for edge cases
I /suppose/ I could maybe use encoders? it’d certainly free up some ARead pins
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as a side-note, if you stick w/ pots and are afraid to run out of ARead inputs, they are some ADC chips (like this one) that allow converting a bunch of analog input to digital.
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you could use pots and just add one button that is “send all midi” that just simply sends the current midi data for all the pots at once. That way the script gets “synced” to the pot values
I did that for my Sweet Sixteen module and it works like a charm for controlling anything midi
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Given shield’s discontinuation, i’m likely gonna be working on a rev2 with the new DAC as soon as the newer PCB files are posted on github.
I’d really like to have balanced audio I/O on 4x3.5mm jacks & the new DAC has the pinout for it (as well as maybe a headphone out, we’ll see)
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Interesting… how did you implemented that send all MIDI button?
presumably if you had pages or banks of pots controlled in software you’d just sequentially read the current pot positions & send out the values on the configured CC’s, which the computer or instrument can then interpret
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just modified the firmware so that if i pushed the one button on the module it would call the midi-send function and I think i wrote a for loop that sends the data for all of the faders
oh yeah definitely do that, that’s the loop for continually reading the pots. What I’m talking about is when you turn everything off and the values within Norns go to default values but the pots are still all set at 50% for example. The pushbutton would then “resync” everything at the start so that you don’t have to turn every pot to resync the pots to whatever value the Norns script has. It’s been a pet peeve of mine that no midi controller has this.
Lemme know if I’m mansplaining this and I’ll just stop lmao
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naw ur good; better thorough than ambiguous. I answered a question directed at you anyway 
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BIG UPDATES (with nothing much to show for it yet)
@tehn uploaded 211028 files to github, so I was able to merge the changes into my design.
Featuring:
- New panel layout
- through-hole jacks
- better noise performance
In practice, this meant redesigning the board around a new nucleus, but it gave me a chance to clean things up a bit & make sure I’m happy with the routing of the traces.
Still considering the possibility of bank-switching for the pots, but homestly that may fall by the wayside
Until next time… hopefully I’ll have PCB’s soom so I can start sourcing the BOM
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ok I’m getting started putting together a github repo for everything, as I think i’m finally approaching the final design
BoM will be largely identical to 211028 aside from the added stuff like pots, enc4, power switch, midi interface, and the grid stuff
Also I redid the panel yet again into what I hope is its final iteration:
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whelp, had to do some surgery. I’d based the newest revision on 211028 assuming the cs4271 version would be preferable but evidently @tehn recommends 210330 as the newer board simply has far more support components (which i’d have known had I read this cool lil doc called a README) 
I ended up carefully snipping the codec & supporting componentry out & dropping in the circuits from 210330. Luckily everything seems happy & it passes DRC so phew
Anyhow, heres the latest PCB & panel layout! files coming soon. I do have to order at least 5 PCB’s so if i can drum up some interest I’ve been thinking I may do a small run of kits. Stay tuned! I appreciate all the hype i’ve been getting here.
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yooo, i hadn’t seen this! just made my deposit for a round 2 retrofit
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