Teletype hardware update

Wow. So if I’m ordering from the next batch of TT, I can just plug Grid directly into TT without ext5v?

Amazing, also heard that the new TT comes with 2 i2c buses making it unnecessary to have the backpack (which also doesn’t fit apparently)?

yes the TT should provide enough power for grids, but there’s a strong chance that there may be noise issues and it’d be better to power it separately.

yes, there are two i2c headers, and pullup resistors tuned for larger networks. i2c backpack will not fit. chain i2c instead.


That’s slightly off topic here but is there a way for previous iterations of Teletype to handle things like keyboards with backlighting without crashing ?

arc is early 2019. (hitting those huge manufacturing speed bumps)

it can handle more power draw, so maybe backlit keyboards will work. this is not something i tested.


I thought Grid would break Teletype - did I get something wrong here?

the latest Teletypes have been revised with powering Grid in mind

I guess i’m not sure how to reconcile these statements?

Ansible obviously handles powering the Grid, but some people still have trouble with a high pitch noise when the Grid is connected (I definitely did when I had one). I’m guessing this is the same deal as what @tehn mentions here about the revised TT. Solutions here: Ansible & grid / power issues?


Right, I totally get that. But if powering the Grid creates noise, why include that power option at all if you still need to power separately?

It seems like grid x teletype integration is one of the most common use cases, so it makes sense to ‘fool-proof’ it so to speak.

1 Like

Probably to prevent people from accidentally blowing up their TT’s, I guess? Or maybe Monome is just evil after all and this is part of a multi-phase plan to exploit the Switch vacuum at a later date.

1 Like

No, i’m generally curious, not making any accusations. If it’s just a safety feature, maybe that can be clarified. As someone who owns a Grid and wants a Teletype, I am interested in figuring out if I need a Switch. I just can’t make heads or tails of it. Thanks!

Sorry, just some end-of-academic-term exhaustion goofiness leaking out. Monome is very nice.

There’s a new (currently hush-hush) module coming from Meng Qi/@scanner_darkly that I’m guessing is related to this, so I’d stay tuned for more news about that.

1 Like

for what it’s worth, all the noise I’ve experienced has been acoustic noise from the Grid’s LEDs. So it’s not actually present in the signal path, but I’ll hear it (very faintly; it hasn’t bothered me) whenever enough LEDs are lit, regardless of what Grid is plugged into.

1 Like

Imagine you have several smaller cases, each of them having their own power supply. One of them is a Skiff housing all you controller & sequencing modules, but no audio modules. In this case a TT that can power the Grid is great, because you will not create the high-pitched grid-power-noise in your audio modules, as these are on a separate power supply.

I remember having two modules that had high-pitched noise issues in the audio path together with the grid, a Frequensteiner and an old Z-DSP, IIRC. But I may be wrong, this has been more than 2 years ago, cases have changed, the Z-DSP is gone, so I can’t recreate that situation.

I still have the Frequensteiner, but this one proved so delicate reg power supply that I ended up putting it on his own µZeus power supply. Now it is really quiet.

1 Like

apologies, let me clarify.

previously, if you plugged a grid into TT and lit up a lot of LEDs, there’s a guarantee you’d hit the limit of 5v for the onboard regulator and eventually brownout the device, meaning it’d undervoltage the screen and likely reset the AVR.

the update to the electronics on this edition of TT was very modest. it has a higher capacity 5V system. so you won’t run out of power.

but this doesn’t change the fact that grids are noisy electrically, and given the nature of euro power systems (covered very extensively elsewhere on the forum) you may have noise bleed onto your power system depending on your power supply, other modules, etc. hence the suggestion that you may still want to split the power for the grid. currently the only option we supply is offworld, but this is now a very common thing for many manufacturers and i’m hoping a standard/cheap/robust splitter cable becomes widely available (ie, a super nice one shipped with the touche)

ps. you can’t really “fry” an old TT with a grid by asking for too much current, due to the fact that it has a DCDC chopper for regulating 5v. the one report of “maybe fried” was just a bad solder joint on the input fuse that happened to fail around the same time as the user started experimenting with grid ops. overcurrent is a very big issue with linear regulators, because they melt and then connect terminals together, ie, the notorious early makenoise power supply with 500ma 5v which upon failure connected 12v to the 5v line and then promptly killed everything on the bus.

edit: i’m branching this thread


Thanks all for the details, much appreciated!

Is there a way to identify my TT, to see whether it’s a revised version?

we haven’t shipped any revised units. those are what we’re shipping starting dec 3.

  • original: green pcb
  • new: black pcb