CM3I with E25 USB3 Options

[chengguizi]

I am about to evaluate the CM3I on the E25 baseboard. I have two questions related to USB3:

1. It is documented that the USB3 OTG port (Type A connector) has an associate button to toggle HOST and Device mode. May I find more documentation on how to use it? It is operate by click to toggle, or must press and hold while plugging in the cable? Could a schematic of the design be provided, so I could take reference of when making new baseboard.

2. The USB-C connector is said to be a power port and serieal console. May I understand if it is a USB2 serial, or a pure UART port? Again a E25 schematics would help a lot.

Currently this is empty:
https://dl.radxa.com/cm3p/e25/

[RadxaNaoki]

1. It is documented that the USB3 OTG port (Type A connector) has an associate button to toggle HOST and Device mode. May I find more documentation on how to use it? It is operate by click to toggle, or must press and hold while plugging in the cable? Could a schematic of the design be provided, so I could take reference of when making new baseboard.

there is a switch to change the role (default is device)

2. The USB-C connector is said to be a power port and serieal console. May I understand if it is a USB2 serial, or a pure UART port? Again a E25 schematics would help a lot.

it’s a USB-serial. you need to connect PC, not power supply.

[chengguizi]

Hi @RadxaNaoki, thanks for the quick reply. Could I obtain a schematic of how this switch is implemented? As I need to deisgn a baseboard to set the OTG to device mode.

For the USB-Serial, is it possible to set in the Firmware / Linux to use the USB as a normal USB2 Host?