TT-Busboard-Jr (a small powered i2c busboard)

I did up a wee variation of the TT busboard…

It’s a compact powered i2c busboard suitable for use with Teletype, Trilogy and other i2c modules. Same voltage regulator and 2.2K pull-up resistors as the Teletype Busboard.

This one is meant to just float freely in the back of your rack (or stuck down with velcro maybe) - rather than directly attached to a module.

(I’ve also got a 1U tile version in the works - I’ll update here when that’s ready)

There’s three 2x3 headers so you could connect up to 6 modules with regular (1x3) i2c jumpers or use a “flying bus” cable to connect multiple modules in series.

I’m hoping this is useful for folks with only non-powered i2c modules (Ansible, Trilogy, JF, etc.)

I have a few built ones and pcbs for sale right now (pm for a link) or you can make your own (Github).

See also: A user's guide to i2c


would this work for connecting an ansible with @scanner_darkly’s poly earthsea to JF? still wrapping my head around the i2c limitations.

yep, i have a prototype and tested it with polyes and can confirm it will work for this use case.


Any possibility these will be available in your store again?

just got asked about this and need to make a few. will try to get on that in the next few days.

i’m about to build one of these to connect to my ansible to pass i2c to the er-301 and just friends via orcas multipass. how are you mounting this in your case?

Some Velcro or something to stick it to an inside surface of your case?

ya i was thinking something along those lines.
tuck tape is incredibly durable and sticky, i’ll try using that on all four side and see how that goes.

That would be awesome!

just picked one of these up (thanks @okyeron!), and it looks great, but after getting everything hooked up, I’m getting a message in druid that ii lines are low. I’m not sure why. I checked all the cables, and they’re all connected properly, ground-ground (I tried flipping them all every which way anyway, but that didn’t fix it). My i2c setup was at least kind of working before, using the same cables (I was getting some weird behavior from w/, which is why I picked up the busboard, but crow was sending messages to jf without any issues). Anyone else run into issues like this with a busboard or have any other ideas for a fix?

EDIT: fixed. Playing around with the order seemed to do the job