Using Type C for AT90USB1286

[Croktopus]

I was wondering if anyone's done this and would be willing to share that part of their schematic, or if someone knows of an open source schematic like this (or with a similar chip like a 32u4). I've given it my best go, but I feel like I've missed something.

My main concerns are

• resistor value
• if i need one resistor or two
• if the resistor needs to be hooked up to any other pins

but if anyone notices other issues, that'd be cool. all i want out of this port is the type c physical port - so reversability, durability, and not needing so many different cables. dont need mega speed

[synonzelra]

Simply saying, usb type c is just a combination of 2 normal usb interfaces with extra pins.

So, the resistor shall be the same as normal usb, as is, 22 ohm.

I would not recommend you to tie usb lines together, like A6 and B6. This will not work on a native type c port.

[dr_derivative]

I often look at this application note from ST about using USB-C connectors. You can see the schematic it uses with two 5.1k resistors on page 16.

I have also seen schematics with just one 5.1k resistor (I think this should work too), but most schematics do use two. Regardless, it should be a 5.1k resistor, not 5.6k.

I would not recommend you to tie usb lines together, like A6 and B6. This will not work on a native type c port.

Tying A6 and B6 together is necessary in a USB-C device. Only one set D+/D- pins is connected through a type-C cable, so the pins need to be connected together to make device work in both orientations.

[Croktopus]

Awesome, thanks for the advice guys. I'm looking at basically copying the circuit design of JayKey1 https://github.com/josuegaleas/JayKey1 since it seems to be doing almost exactly what I want

[dr_derivative]

Awesome, thanks for the advice guys. I'm looking at basically copying the circuit design of JayKey1 https://github.com/josuegaleas/JayKey1 since it seems to be doing almost exactly what I want

That schematic looks good to me. Good luck with your design!