Multiple Modules

[Mechboards]

Hello all,

I'm looking at creating a Let's Split with 2/3 extra modules. could I daisy chain these using TRRS Jacks/cables or would the power output be too much for all these to work? Or course I'd have a master slave that's always plugged in, but then modules feeding off of that, or each other.

Any help would be appreciated (wiring 4 modules together for use together or minus modules)

Cheers!

David

[cribbit]

When you say "extra modules" do you mean more of the 4x6 halves?

I'd be curious as to whether you'll need an extra headphone jack on each module in order to do a real daisy chain or whether you can just use a headphone splitter. You'll certainly need some firmware work either way.

I wouldn't be worried about the power requirement, as long as you're not running LEDs. For just switches you can run quite a number of modules, in theory.

If you don't need modifier keys to be usable across modules or are comfortable using software fixes such as AHK for modifiers across modules then you can make each module a separate keyboard and have your daisy chaining just be USB splitters built into the units.

It's certainly a cool concept, cool enough that I wish there was more applications for it.

[Mechboards]

When you say "extra modules" do you mean more of the 4x6 halves?

I'd be curious as to whether you'll need an extra headphone jack on each module in order to do a real daisy chain or whether you can just use a headphone splitter. You'll certainly need some firmware work either way.

I wouldn't be worried about the power requirement, as long as you're not running LEDs. For just switches you can run quite a number of modules, in theory.

If you don't need modifier keys to be usable across modules or are comfortable using software fixes such as AHK for modifiers across modules then you can make each module a separate keyboard and have your daisy chaining just be USB splitters built into the units.

It's certainly a cool concept, cool enough that I wish there was more applications for it.

Thanks for the reply.

It's an idea using the way the Let's Split works, so 4 modules in total. Imagine a Let's Split kit with 2 extra modules as the basic idea.

The firmware will be the tricky part. I assume as each module wouldn't have an Arduino board i can't just flash each with their own layout? Or if I did, is that possible?

Daisy Chain with USB splitters sounds interesting.

[cribbit]

I don't know how closely you've studied the let's split design. To my basic understanding, each module has an arduino in it (they're like $3 each). When you plug the USB into an LS module it knows its layout and is just a small keyboard at that point. It listens for data through the TRRS. This data is just matrix locations, not keycodes. The "master" LS determines what keycodes to send using its mapping. Thus, you can switch layouts on an LS just by switching the USB from one half to the other.

For the USB splitting, you would replace the TRRS with a USB port and each LS module would emulate being a USB splitter with a keyboard attached (this is how Apple's aluminum boards do their USB ports and how USB boards can achieve more than 6 key rollover). Thus, each additional module just plugs into the end of the chain. From a firmware and PCB redesign standpoint this is actually your easiest path. Your big downside is that you lose modifiers across the boards - it's literally the same as just plugging in the modules all straight to the computer.

Pretty much any design you do, it's far easier to just have each board have its own arduino.