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Any other modules with I2C output like Teletype?


Is there anything else?

If not I think there could be a few that would be nice to make, a dedicated ER-301 controller that uses this protocol would be lovely, don’tchathink?

Besides Teletype, are there any other units that can connect directly to ER-301 via i2c bus?

i2c talks with Just Friends and @bpcmusic made the Telex TXo and TXi for output and input respectively that also talk via i2c and extend the Teletype. I’m right now waiting for my modified CPU to return for my ER-301 so I can jump into that aspect of communication…


If I recall correctly, Tetrapad has i2c, but no implementation (yet).


you’d need something that would work as an i2c master. right now only teletype does it, everything else runs as i2c slaves. it would be possible to change, say, TXi or ansible to work as a master but that would require a firmware mod.

having said that there are i2c libraries for pretty much every platform, so it’d be very easy to implement it - the protocol itself and the structure of tt commands is very straight forward.


Thanks everyone!

@scanner_darkly Okay, I just had a quick look, so for example, a very simple module with 12 knobs (ABCD123) literally just offsets, no jacks out or any other features, is totally the sort of thing that could be achieved with an Arduino! This would effectively double or ‘free up’ the inputs on the ER-301. I would use this a lot because it would free up my offsets in more complex modules and provide a coherent and playable interface with enough controls for most of my custom units.

It’s actually been on my mind for a while and i kept thinking of building an analogue control surface like this, or a midi one - but both ideas haven’t taken off because of the obvious limitations, this is much more appealing!

When things get quiet again (I am ridiculously busy at the moment) I might have a go, because this doesn’t sound too difficult at all :slight_smile:

Unless anyone else does it in the mean time :wink:



take a look at the faderbank project:

it would be trivial to modify the firmware to have it control er-301 directly.


That looks very nice - thanks!!

Juice in this post for anyone else reading:


Are there any boxes for going from MIDI to I2C? Would be a cool way to use some existing controllers/sequencers with 301.

I found this after a quick search:



Not a bad idea - although you’re still working with midi so things like CC to CV only have 128 steps so it can sound ‘steppy’ - but then again, no reason smoothing couldn’t be applied as in the Endorpin.es Shuttle Control which works well!

Also, I was thinking that a ‘little box’ could take outputs from any modules with pin headers on the back and convert it to I2C.


I’ve thought about cooking something up along these lines, but I think I will wait until access to the UART is made available through the SDK. A MIDI-I2C bridge would incur additional latency (and possibly jitter, if there is a lot of chatter on the I2C bus). The Teletype is only operating at 100kbaud, and since the messaging format is more verbose, there doesn’t seem to be sufficient bandwidth to offer significant benefits over native MIDI (someone please correct me if I’m wrong about that – I would love to be).

Also, MIDI is not limited to 7 bits; it also supports 14-bit messages. Pitchbend is the most common example, but there is also high resolution velocity and 14-bit CCs/NRPNs. The high resolution stuff is not common, but there are examples out in the wild (Behringer B Controls, Faderfox products, etc.).


Even just having it send gates from MIDI note on/off would be plenty in my mind, that would open up tons of usage with hardware sequencers.

@miminashi Please keep us posted about your cooking, sounds neat! :slight_smile:


Just curious what all the options are here. I have a very small 72HP custom case, and trying to make the most of out of all the pots.


This is not meant to call anyone or be an act of “political correctness enforcement”, but, I have been trying to be mindful of the “master and slave” terminology that is so common in describing the control relationships between devices. And I am wondering if there is any way we can still be precise in talking about audio things, but without that hideous metaphor casually lurking in the language? What other words can be used?

EDIT: Transmitter and Receiver seems like a nice idea. Thanks for the suggestion @kel !


we’ve been trying to use “leader/follower” in the latest discussions on lines. we’ll see if it sticks, can be hard using the new language when all the docs/online content uses the old terminology…

re: receiver/transmitter - i like it but there are cases where followers transmit as well (when the leader asks them to send something back).


Why not use master and client? Would be more accurate as well.


if you leave out the purpose of what i2c communications are used for in any particular case, the only difference really is who initiates a transmission. with master/client you could say that the master is actually the client who is consuming information.

leader/follower also doesn’t feel 100% right tbh but does emphasize the above aspect - a leader initiates a transmission, which followers then respond to by either simply acknowledging it or transmitting something in response.


To my knowledge there are not yet any other modules that fit this description.