Teletype and ER-301 Basics

The advancement of integration between the Monome Teletype and ER-301 opens a channel of communication via the i2c connection on the back of the Teletype and three pins on the back of the ER-301. This connectivity allows the Teletype to talk to the ER-301 via this “back-channel” cable thus allowing the 20 ER-301 front-side inputs to be used for other purposes.

The two main functions of communication between the devices is the sending of triggers and CV from the Teletype to the ER-301, this is not bi-directional at this time.

The Teletype is a script driven module with open-source firmware that is allowing member of the Monome community to code this integration with the help of @odevices altering his ER-301 firmware and identifying the connection points for this process to advance. On the Teletype side we have @bpcmusic who lead the effort with @scanner_darkly working on some integration too.

With this development the Teletype is able to create and manage 100 trigger/gate ins and 100 CV ins allowing unheard of control of units within the ER-301, all while leaving the physical inputs on the front of it free for other purposes.

Why is this beneficial beyond the obvious extra triggers/gates/CV?

The Monome Teletype firmware is under near constant development similar to the ER-301 at this time. This has allowed developers to constantly refine the firmware and add things such as; Euclidean rhythms, chaos maps for randomized sequencing, Monome Grid integration and emulation, advanced math operations such as Bitwise operators, a Turtle operator for more randomness, expansion capability for adding additional ins/out via Telex modules, ability to use multiple commands per line, and then there’s the very foundation of the Teletype’s myriad of functionality that all of this sits on. By the way, a 16 channel faderbank is in the works with firmware hooks being integrated into the v2.3 candidate.

All of this comes with a fairly steep learning curve and it certainly doesn’t fit in anyone’s “one-knob one-function” philosophy. This setup is complex and as of this writing no one has scratched the surface of what’s possible. The Teletype communicates first and foremost with a USB computer keyboard attached to its front side. The scripts are limited to available screen space and only 6 lines. From there you will find a Metronome script, an Initialize script, 8 scripts that relate to the front side trigger/CV ports and a 4 track 64 step pattern tracker. (Conversations have been ongoing for over a year of expanding some of this through a “Timeline” function that I don’t quite understand yet and of increasing the number of pattern tracks)

With this event and logic driven system users of this setup between the Teletype and ER-301 have the opportunity to extend not only functionality but the complexity of what is able to be explored via scripts and interfaces that are evolving and are still being invented.

There is nothing inherently necessary to have both modules in a system to enjoy the capability of either. They do though compliment one another quite incredibly.

Documentation is thin, but maybe this thread can be a starting point for sharing “Best of” lessons along with tips and tricks of working with these powerful tools.


Nice write up, @Unity2k. Very concise and informative.

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Awesome, @Unity2k!

I’d add that any script can trigger any output, and the relation between the 8 trigger ins and the 8 scripts can be bypassed by recalling any script from any other script.

(For example here I’m launching script 1 from script M, every two metronome ticks:



Thinking about adding an additional modulation source for the 301, was originally looking at Pam’s New Workout and wasn’t looking at the Teletype due to the keyboard scenario, but I’m starting to open up to the idea, especially given the advantages of freeing up the CV inputs on the 301 by using the i2c.

But I’m still struggling with what the hell Teletype is, haha. I’m gonna start going through the studies videos to get a better sense. But generally speaking, could a script be written on it that would give similar functionality as Pam’s? I’m guessing the answer is “Yes…and more.” Other broad insights into why you like Teletype are welcome. :slight_smile:

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Yes! It’s been a while :slight_smile:

I have one on it’s way (it’s been on it’s way a really long time - Parcel Farce are playing their usual games of sheer incompetence) and am keen to hear what folk have been up to with this pair.

Any scripts / patches to share?

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About the “keyboard scenario”:
I will just say that one way to think of this is that you program a scene that makes the TT do a bunch of things you like to have happen in the patch, unplug your keyboard, and explore that functionality set, the same you would with any other module with set functionality.
I personally do this quite frequently.

Same as with monome grid and/or interfaces, which work with multiple monome modules, and effectively have modules run without the interfaces actively being connected to them.

Y’all will think this is crazy, but I actually have TWO Teletypes, but intentionally use only one keyboard, which encourages me to develop scripts that deliver complex ideas/functions without the need for keyboard to be actively used/connected at all times.


Also, it helps to have a keyboard you actually like! :smile:
I love this cute little thing!


That does indeed look cute. Do you miss the dedicated number and arrow keys though?

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Not really, I got used to the fn key combinations very quickly.

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May I ask where you got this? It looks similar to a “”, but those seem to be kits only.

I got mine second hand. But new are here (and other places):

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Unfortunately this is one area where Teletype is not ideal. Without the Telex expanders it can’t output continuous variable voltage (I.e. oscillators). It’s great for triggers and set voltages…

With the Telex TXo expander the Teletype can do all these things and more, you just have to write the script.

To provide a counterpoint to @laborcamp - I had a Teletype and expanders for a long time and just found it didn’t mesh with my workflow. Pam’s, or other more dedicated modules, offer an immediacy and “happy accidents” that you don’t get from the Teletype. On the other hand, the Teletype offers ways of building intentional and generative systems that nothing else does.


I wish i could control the 301 with Ansible and the Grid (+ Op-1 keys) directly via i2c, bypassing teletype (got no free space and really not keen on bringing programming to my modular workflow). This would free the inputs and make everything much more immediate.

Right, so the fun part/advantage is that you can write your own functionality when you want, but otherwise you’re just treating it like any other module sans keyboard.

Oh interesting, I assumed it was a WASD keyboard. Those things GAS me hard, the custom colour schemes/fonts, drool.

Something I just thought of: Yes that applies to the Teletype’s front panel output, but that wouldn’t matter if it’s communicating over i2c, correct? I’m assuming it can send ‘CV’ over i2c directly to the 301?

Good perspective, thanks. Funny, like with most things in life, it’s a question of choosing between playing the short game or the long game.

Do you have a really rudimentary example of what the ‘intentional and generative systems’ would actually look like? That’s the part I’m having a hard time parsing from the documentation of the TT. Gah, I clearly just need to read/watch more about it…


I don’t think you’re alone in trying to visualize exactly what you’d do with it without actually having one in front of you. I’m definitely having a hard time doing it myself, and have gone through all the case studies on their site. I assume if I could sit in front of one for a couple of hours I’d probably say “AHA!” and proceed to empty my wallet. :slight_smile:


Ha, yeah, maybe we don’t actually want to know what is does for fear of going broke!

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I’m wishing the VCV rack version would become available to mortals, soon.


I don’t think it will do continuous cv like LFO etc even over i2c. It’s not part of the core Teletype scripting language right now.

What it’s great at is setting up systems of events. Like … if trigger 1 is fired then do these 10 things. It also lets you store basic patterns of data, and now you can also use it to build interfaces for the Monome grid.

You can do some math and randomness with it that’s really unique.

Imagine a really simple scripting language for events. “On trigger 2 if pattern data > 5 send 10 triggers to output 2 and set cv 1 to a random note from this scale”…


Expanders seem to add a lot!!

I am definitely going to build some, if anyone interested UK/EU let me know and we can work something out :slight_smile:

Well anyone WW can let me know too, I just figured it would be easier to buy direct in that case, but maybe they won’t be available, so yeah - open offer :wink:

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The ER-301 excels at this. I assume TT would be useful for turning it’s continuous CV chains on/off at specific times, or adjusting attenuation, or any other modulatable parameter in response to a clock?