#294

@moderators can we split this thread for Mangu’s Sweet Sixteen? Starting at the photo post above?

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#295

Well - if the hardware actually is derivative of the 16n hardware - ie, you started with our schematics or boards, you have to share your own implementation under CC-BY-SA. But: I know you could re-implement the hardware from scratch based purely on the firmware, with no reference to the original boards, and you wouldn’t have to share that if you didn’t want to.

The firmware doesn’t have to be shared - MIT License only requires you to include the license with your own work, but you don’t have to publish the sourcecode for derivatives. I was just genuinely curious as to how it was implemented!

It’s a really nice adaptation, and I think it’s more interesting than the ‘straight up’ 50hp version.

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#296

In such case i have to share the files. Some parts of the schematic are literally from the faderbank (midi, 4067, i2c) other parts from other modules i made, others from scratch…a litle frankeisntein. But i will make public the files when is a solid thing so people could order files and build without cutting traces and wiring… This first version has some (stupid) mistakes, apart, need to make a decisions about the voltage range, 5v is not enough for most eurorack gear, and need to match values of the ldo reg, voltage references and summing and feedback resistors . The firmware is working fine, got another addon in mind for generating notes, the result would be pretty random if used with cv in the inputs instead of gates, but useful for percutive things.

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#297

Yesterday the Micro USB port of my 16n broke. I didn’t build the 16n myself, so could anybody tell me how difficult it is to replace the Teensy? Also, is it possible to have a more sturdy USB port? Mine felt wobbly and fragile from the very start.

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#298

Others seem to have replaced the usb socket alone on the Teensy, without desoldering it; I don’t have the details of the part, but it sounds doable. Removing the Teensy is moderately challenging but not impossible on the 1.3x line of boards.

“Sturdier USB port” - well, one alternative has been built by @MichiganSynthWorks, which adds a through-hole mini-usb-B port to the main board, which pipes through to the Teensy.

My preferred option would be redesigning the thing so no Teensy at all was needed, and I’d probably use a full-sized USB-B port that anchors to the board. I have napkin sketches of that project, but have not had time to work anything up yet. It would be a new thing, in the sense that it would have new firmware as well as everything else. (“Why didn’t you do this before?” Well, this was meant to be a simple extension of an existing project…)

“Ports falling off” largely come down to how the Teensy is built, which is reasonable for a development tool, but perhaps not stage robust.

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#299

Ahoy.

If you have a 16n, and are using I2C for (eg) an ER-301, TXO, or Ansible with it, your assistance debugging a current build of the firwmare - as mentioned in the other 16n thread would be invaluable. I do not own these items.

We have a bug wherein a 16n in MASTER mode, when not connected to I2C, just freezes as a MIDI device. (It works fine over CV, obviously). I have now got, I think, a fix for that bug - or rather, I’ve definitely fixed the “freezing” issue. What I can’t confirm is whether or not there’s been any regression in the I2C functionality, because I don’t have an I2C rig set up.

Given there are lots of people with these things, assistance would be valuable. Thanks!

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#300

on several occasions, i have resorted to this caveman “solution” for fragile micro-usb ports on teensy’s, pi’s: (and even upcycled android phones): a panel-mount extension cable.

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#301

I’ve been using a cable similar to this one successfully:

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#302

tried to compile your firmware for teensy LC… (both ttmidi and ttmidi2 branches)

no dice, as it exceeds ram.

error

/Applications/Arduino.app/Contents/Java/hardware/tools/arm/bin/…/lib/gcc/arm-none-eabi/5.4.1/…/…/…/…/arm-none-eabi/bin/ld: /var/folders/7s/5jhnrp157qz_vn8z43_t3rr80000gn/T/arduino_build_3478/_16n_faderbank_firmware.ino.elf section .bss' will not fit in regionRAM’
/Applications/Arduino.app/Contents/Java/hardware/tools/arm/bin/…/lib/gcc/arm-none-eabi/5.4.1/…/…/…/…/arm-none-eabi/bin/ld: region `RAM’ overflowed by 5136 bytes
collect2: error: ld returned 1 exit status
Error compiling for board Teensy LC.

I’m able to compile the current head of the official master branch for the LC.

any idea if/how one could optimize your implementation? I tried reducing the polyphony, but even with value 1 the same error occurs (with minimal impact of < 100 bytes)

thanks!

edit: ok, so played around with channelCount… with value 1 it uses 65% of dynamic memory (vs. 40% on the official firmware)
With that build I could send midi to the er301 (horray!), which is my current use case (though wanted to check out tt midi too).
so probably it’s just all too much for the LC… but could I reduce the build to the er301 functionality? i’ll try to find out :slight_smile:

(if anyone is wondering, hw side I’m using an axoloti as host for the 16n to input din-midi. awesome!)

#303

yeah, the biggest gain (without doing a more major refactoring) would be to reduce the size of lastCCValue. you could do that by limiting the number of MIDI channels you use, or limiting the number of MIDI CCs you want to support (in which case instead of using the actual CC number as this array’s index you would store the index of another array which will have the actual CC numbers).

also, do you need to send CCs or just notes? the array is only used for CCs, so you could just set maxCCCount to 1 (or just remove it and the related code altogether). if you do need CCs, another easy gain is to change the array type from int to byte.

#304

awesome! many thanks for these very valuable hints!
and for your work altogether!! :pray:

#305

I saw that you did the alt firmware for using the 16n as a Midi to I2C converter. Since I could not really find an answer: Is it possible to send standard note on off messages to the 16n via USB and have that reflected on the I2C somehow? Trying to shove Midi through to my ER301 via the I2C connection from Ableton.
Or is your firmware only for using it with teletype? Also if the above is possible, what channels/notes should I send the commands on??
Any help would be really appreciated thanks!

#306

yeah, you can use this version: https://github.com/scanner-darkly/16n/tree/ttmidi2

it will convert MIDI notes from either mini jack MIDI or USB MIDI to er-301 or just friends i2c commands. MIDI channels 1-6 will correspond to JF voices 1-6. for er-301 MIDI channels 1-8 will correspond to SC.CV SC.TR 17…24 (first 16 are reserved for faderbank itself). velocity will be output on SC.CV 25…32 (this is assuming you have polyphony set to 8).

make sure to change settings appropriately here: https://github.com/scanner-darkly/16n/blob/ttmidi2/firmware/_16n_faderbank_firmware/config.h#L33

3 Likes
#307

Thanks so much! The problem now though is even though I have tried pretty much all of the different firmwares on the github by now I am no longer getting a response from my 301 over i2c which was responding at first when I checked it. (Master mode is checked obviously) Kind of afraid that i might have accidentally hot plugged the i2c without noticing… Is there any way to check it without a scope (haven’t got one…) what’s about the worst thing that could have happened? :grimacing:thanks!

#308

check port number on er-301, maybe it got changed accidentally after flashing a new version? if it’s a hardware issue perhaps folks more knowledgeable about the hardware side of things could help!

#309

Thanks for the quick reply! I think I finally got it after like 5 hours… Seems like there was actually something wrong with the hardware connection, although checking it with the continuity tester on my multimeter said it was ok… :roll_eyes:
Also Thanks so much for the alt firmware! Got it to work like that:) Already dreaming up a scenario of what crazy kind of things I could build by having the 301 and other midi gear working together whilst still being able to modulate stuff with the modular :blush:

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#310

Hey @scanner_darkly - beautiful work! Will be trying it out at once! As @iiii, I also thought about if the new firmware needs any consideration, doing this?

#311

sorry, not sure what your question is?

#312

@scanner_darkly Sorry for being being unclear. Nvm the question.

I have set it up with ttmidi2 and it works! However, I experience some heavy jitter. Have you encountered that? Do you have a stable way of using it?

I route Cirklon into Bome Box (midi to usb host) into 16n into TELEXb into ER-301. Kind of heavy midi signal chain i guess. I wonder if this might cause the problem. I have no jitter with the faders on 16n

Here is a video where you can hear the timing jitter (pitch change on osc) - especially when i apply the vca which i trigger from the velocity signal, where you can also see the length of notes differ a lot (and it is also very low on its output.? :thinking:)

#313

i would try and rule out MIDI to USB conversion first. are you able to test it with something else?

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