a773
183
Could you post entire scene (export to use stick, copy past text to here), it’s much easier to help (and get help) this way…
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It’s from Retrokits. They also offer a cable that swaps from A to B.
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I recently got a Midi to TRS DIY kit from Transient Modules at Thonk:
Great and cheap little adapter, easy to solder and with type A and B switch
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Excellent idea and loads of potential. What about bi-directional?
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I feel like this would be more useful as midi CCS than as midi notes (since I’m not sure Teletype could poll an i2c input fast enough to make keyboard input playable), but i2c2midi converting midi CCS to messages readable by the 16n faderbank i2c ops could probably be doable. Getting midi CCS readable in the way Teletypes Param is readable has been something I have been wanting for a while.
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Yes, I have been thinking about this, too. It would require some changes in the hardware as well, to add a second TRS jack for MIDI input.
Since TT is the always the leader in this scenario, the only way is to poll data – much like with the 16n fadebank, as @nonverbalpoetry pointed out.
However, I don’t want to “hijack” the 16n OPs (as I did with the EX OPs), since the 16n OPs only work for one device (correct?). Maybe the generic I2C OPs would be a better choice. I believe they also allow to poll / query data … I have to check again.
My personal dream would be a few special OPs for i2c2midi of course, but I would never dare to ask for that 
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Or, just make it an alt firmware for i2c2midi (midi2i2c) so it’s the same hardware but you just need two modules?
Custom i2c2midi ops would be so good
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I love that idea, unfortunately the circuit for MIDI in is significantly different from MIDI out – so it can’t be the same, at least not with the current hardware.
a773
191
Pro-tip: before you spend an hour scratching your head, tearing stuff apart and debugging your entire setup, make sure the MIDI cable is in fact plugged into the jack on your i2c2midi module…
7 Likes
re: bidirectional MIDI
you can simply use the USB port and MIDI IN ops to react to notes / CC messages / transport messages. this does tie up the USB port though.
doing it in i2c2midi would require i2c2midi storing the received MIDI messages and teletype polling for them periodically as mentioned. one possible solution would be adding a trigger output to i2c2midi to send a trigger whenever a MIDI message is received, then you could simply use a trigger input on teletype to trigger a script that would poll for new messages.
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I am happy to announce ––
i2c2midi MKII
The circuit and PCB have been redesigned, cutting the module width in half to 2 HP and adding USB MIDI. It’s now using Teensy 3.6.
The USB connection can be used for USB MIDI out or in.
It is USB Host, which makes it possible to connect external MIDI controllers (MIDI in) and external MIDI USB devices (MIDI out) directly without a computer.
I am happy to report, that the USB MIDI out connection also works with the OP-1 
–
If a MIDI controller is connected, all incoming MIDI CC messages (127 * 16 channels = 2032 values total) are stored internally in i2c2midi, and can be requested by Teletype at any time, using the generic I2C OPs:
IAA 66
IIB1 channel controller
Using the script above, i2c2midi will answer with the currently stored value for the requested controller number and channel. This is obviously not suited for “real-time” MIDI control like playing a keyboard, but if a fast response is needed, calling the script above in regular intervals (e.g. from M) works well for knobs and faders.
All of this works independent from sending MIDI out via TRS.
–
Big thanks to @nonverbalpoetry and @Cristian_Vogel for inspiring me to add USB Host.
I will add Gerber files and build guide to the repo in the coming days.
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xmacex
194
Ooh I’m like: 
Teletype ⇆ this thing ⇆ norns?
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Original 4hp version with a usb plugged into the teensy- yes absoloutley that works and is my main use case, but only works for midi out, not midi in (unless code gets modified - this seems possible?)
2hp 2.0 version- no, this won’t work as they would both be acting as hosts and so wouldn’t be able to communicate
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xmacex
196
Oh i misinterpreted the top ← arrow as bringing USB midi host in, rather than acting as midi host. It says so in the writing… 
Either way this is super.
Also I’m thinking
The Lego plate was a stellar idea
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Amazing!
The mk2 looks awesome.
Really looking forward to building one and getting my op-1 in the mix.
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Was hoping you’d say that!
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phaelam
200
New here, been following this thread, and am going to ask questions that has the potential of making me come off like and idiot…
First off, this module looks amazing. I was wondering could this be used to take general MIDI, say from a controller, or some random hardware, to communicate via i2c to an ER-301?
If yes, as I am not technically inclined, can this module be purchased built?
Also would the be able to output the CV from the ER-301?
Thanks.
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I’m afraid not, both this and er301 are i2c followers, they only respond to commands. Something like teletype or crow would need to fetch midi from i2c2midi, process it, then send it to er301.
It is only available as DIY, but is incredibly simple and would make an excellent introduction to the world of DIY modules
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phaelam
202
Thanks for getting back to me so quickly.
Well…I am downsizing. Perhaps after selling a bunch of pieces, I suppose I could fill a hole with a Teletype.
My confidence with a soldering iron is gone. I destroyed a Machinedrum trying to do a screen replace. That’s why I try to get someone to build for me if I can.
Thanks again. I’d love to integrate that module somehow someday. Looks great too 
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