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I2C communication with Monome Teletype


Or set the gain to 10 and send SC.CV 1 V 3 :grinning:
Also, there is the VV modifier… Which gives you 100 steps "per volt"
In the example above it would be:
SC.CV 1 VV 300 = speed 3.0
SC.CV 1 VV 50 = speed 0.5


Everything makes sense now. Thank you so much.


Cool. I didn’t know about that one. :star_struck:


Unfortunately you can’t set the gain to 10.


Now that i got it, here’s a sample player, driven by TT making octave jumps and slice selection :


gosh i think i’m too old…programming, scripts, typing, no cables… soon we all work on a single screen with no physical objects and a weird mouse device to make music :zipper_mouth_face:


I’ve collected the critical information concerning Teletype integration that was scattered about this thread into one wiki page:



(quietly crosses internet browser off of the feature request list)


I should point out one important thing for those not following along in the TT threads on the monome forum (or who might need reminding):

If you plan to connect more than (approximately) three devices to your Teletype’s i2c bus, you will need to get a powered bus board.

The good news is that there are available from Monome, from me, and as an open source project if you want to make one yourself (it has three SMD parts and a lot of through-hole headers). Links below.

Without the bus board, larger device configurations become unreliable - potentially causing your device or Teletype to freeze and require reboot. The good news is that the bus board works like a charm. I’ve had 16 TXo and TXi connected to my teletype reading and writing at hyperspeed without issue.

The reason you need this is due to the way the i2c bus works and the changes that multiple devices and longer cable runs make to the bus. There needs to be more “pull-up” in order for communications to be stable. The good news is that the bus board does this for you. :slight_smile:


i know right? what’s next?? a modular inside a module?? a computer inside a module, virtualised inside a computer??? crazy times indeed :scream:


I’m confused. What rate does the I2C bus operate at? I’m trying to mentally bound the performance.


the baudrate teletype currently uses is 100,000. the actual rate will be also determined by the length of the command and how it’s scripted and the response of the i2c slave.

let’s take the simplest case, updating everything in one loop. i just did a [very unscientific] test - a loop executing an i2c command 30,000 times takes 6-7 seconds. for er-301 case the most extreme case we’ll have is updating 100 values “at once”, if i try that it seems pretty instantaneous.

i think this is one of the most interesting use cases for er-301/teletype integration, having a patch that utilizes all or almost all of the 100 values available and updating them at once (imagine a 100 band filterbank, being morphed, for instance…).

i’m curious about this though:

i would expect that updating SC.CV would be instantaneous as there is no hardware to “settle”, it’s just updating some internal value, but perhaps there is some additional latency on the er-301 due to how it’s handled internally. would it be possible to eliminate this delay completely?


maybe i’m dreaming a bit… but in the future, is it possible we can we see a er101/102 have a teletype integration too ? i don’t know if it’s possible with the hardware…


Cool, thanks for the info.


Funny thought - maybe you’re not old enough if you think about it, teletype being strongly influenced by early computers. :smile:


I was so happy with my setup until I read this thread, now I have gas again :joy_cat:


My CPU is out for modification right now! I have two TXo’s and one TXi. My busboard is mounted behind a Teletype and is also connected to my Just Friends. My ER-301 being dark while the CPU is modded is nearly depressing.


I did the mod and update/s yesterday and everything is working wonderfully! I’m not very good at soldering, so I was quite nervous at first, but with the info and pictures in the wiki I was able to hack it. This is really exciting stuff. I2c all the things! :star_struck:



i can’t install ER301 teletype firmware, i have this message :
update failed : could not copy MLO

any idea please ?


You are not giving the firmware updater a proper zip file probably. Are you following these instructions exactly?